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PROPOSED STANDARD
Internet Engineering Task Force (IETF)                        J. Quittek
Request for Comments: 7577                                     R. Winter
Category: Standards Track                                       T. Dietz
ISSN: 2070-1721                                         NEC Europe, Ltd.
                                                               July 2015


          Definition of Managed Objects for Battery Monitoring

Abstract

   This memo defines a portion of the Management Information Base (MIB)
   for use with network management protocols in the Internet community.
   In particular, it defines managed objects that provide information on
   the status of batteries in managed devices.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7577.

Copyright Notice

   Copyright (c) 2015 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.







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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  The Internet-Standard Management Framework  . . . . . . . . .   5
   3.  Design of the Battery MIB Module  . . . . . . . . . . . . . .   6
     3.1.  MIB Module Structure  . . . . . . . . . . . . . . . . . .   6
     3.2.  Battery Technologies  . . . . . . . . . . . . . . . . . .   8
       3.2.1.  Guidelines for Adding Battery Technologies  . . . . .   9
     3.3.  Battery Identification  . . . . . . . . . . . . . . . . .   9
     3.4.  Charging Cycles . . . . . . . . . . . . . . . . . . . . .  10
     3.5.  Charge Control  . . . . . . . . . . . . . . . . . . . . .  10
     3.6.  Imported Definitions  . . . . . . . . . . . . . . . . . .  11
   4.  Definitions . . . . . . . . . . . . . . . . . . . . . . . . .  11
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  33
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  36
     6.1.  SMI Object Identifier Registration  . . . . . . . . . . .  36
     6.2.  Battery Technology Registration . . . . . . . . . . . . .  36
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  37
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .  37
     7.2.  Informative References  . . . . . . . . . . . . . . . . .  38
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .  40
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  40

1.  Introduction

   Today, more and more managed devices contain batteries that supply
   them with power when disconnected from electrical power distribution
   grids.  Common examples are nomadic and mobile devices, such as
   notebook computers, netbooks, and smartphones.  The status of
   batteries in such a device, particularly the charging status, is
   typically controlled by automatic functions that act locally on the
   device and manually by users of the device.

   In addition to this, there is a need to monitor battery status of
   these devices by network management systems.  This document defines a
   portion of the Management Information Base (MIB) that provides a
   means for monitoring batteries in or attached to managed devices.
   The Battery MIB module defined in Section 4 meets the requirements
   for monitoring the status of batteries specified in RFC 6988
   [RFC6988].

   The Battery MIB module provides for monitoring the battery status.
   According to the framework for energy management [RFC7326], it is an
   Energy Managed Object; thus, MIB modules such as the Power and Energy
   Monitoring MIB [RFC7460] could, in principle, be implemented for
   batteries.  The Battery MIB extends the more generic aspects of
   energy management by adding battery-specific information.  Amongst
   other things, the Battery MIB enables the monitoring of:



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   o  the current charge of a battery,

   o  the age of a battery (charging cycles),

   o  the state of a battery (e.g., being recharged),

   o  last usage of a battery, and

   o  maximum energy provided by a battery (remaining and total
      capacity).

   Further, means are provided for battery-powered devices to send
   notifications to inform the management system of needed replacement
   when the current battery charge has dropped below a certain
   threshold.  The same applies to the age of a battery.

   Many battery-driven devices have existing instrumentation for
   monitoring the battery status because this is already needed for
   local control of the battery by the device.  This reduces the effort
   for implementing the managed objects defined in this document.  For
   many devices, only additional software will be needed; no additional
   hardware instrumentation for battery monitoring is necessary.

   Since there are a lot of devices in use that contain more than one
   battery, means for battery monitoring defined in this document
   support addressing multiple batteries within a single device.  Also,
   batteries today often come in packages that can include
   identification and might contain additional hardware and firmware.
   The former allows tracing a battery and allows continuous monitoring
   even if the battery is installed in another device.  The firmware
   version is useful information as the battery behavior might be
   different for different firmware versions.

   Not explicitly in the scope of definitions in this document are very
   small backup batteries, for example, batteries used on a PC
   motherboard to run the clock circuit and retain configuration memory
   while the system is turned off.  Other means may be required for
   reporting on these batteries.  However, the MIB module defined in
   Section 3.1 can be used for this purpose.

   A traditional type of managed device containing batteries is an
   Uninterruptible Power Supply (UPS) system; these supply other devices
   with electrical energy when the main power supply fails.  There is
   already a MIB module for managing UPS systems defined in RFC 1628
   [RFC1628].  The UPS MIB module includes managed objects for
   monitoring the batteries contained in a UPS system.  However, the
   information provided by the UPS MIB objects is limited and tailored
   to the particular needs of UPS systems.



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   A huge variety of battery technologies are available, and they are
   evolving over time.  For different applications, different battery
   technologies are preferable, for example, because of different
   weight, cost, robustness, charging time, etc.  Some technologies,
   such as lead-acid batteries, are continuously in use for decades,
   while others, such as nickel-based battery technologies (nickel-
   cadmium and nickel-metal hydride), have, to a wide extent, been
   replaced by lithium-based battery technologies (lithium-ion and
   lithium polymer).

   The Battery MIB module uses a generic abstraction of batteries that
   is independent of particular battery technologies and expected to be
   applicable to future technologies as well.  While identification of a
   particular battery technology is supported by an extensible list of
   battery technology identifiers (see Section 3.2), individual
   properties of the technologies are not modeled by the abstraction.
   In particular, methods for charging a battery, and the parameters of
   those methods, which vary greatly between different technologies are
   not individually modeled.

   Instead, the Battery MIB module uses a simple common charging model
   with batteries being in one of the following states: 'charging',
   'maintaining charge', 'not charging', and 'discharging'.  Control of
   the charging process is limited to requests for transitions between
   these states.  For charging controllers that use charging state
   engines with more states, implementations of the Battery MIB module
   need to map those states to the four listed above.

   For energy management systems that require finer-grained control of
   the battery charging process, additional means need to be developed;
   for example, MIB modules that model richer sets of charging states
   and parameters for charging states.

   All use cases sketched above assume that the batteries are contained
   in a managed entity.  In a typical case, this entity also hosts the
   SNMP applications (command responder and notification generator) and
   the charging controller for contained batteries.  For definitions in
   this document, it is not strictly required that batteries be
   contained in the same managed entity, even though the Battery MIB
   module (defined further below) uses the containment tree of the
   Entity MIB module [RFC6933] for battery indexing.

   External batteries can be supported as long as the charging
   controller for these batteries is connected to the SNMP applications
   that implement the Battery MIB module.  An example with an external
   battery is shown in the figure below.  It illustrates that the
   Battery MIB module is designed as an interface between the management
   system and battery charging controller.  Out of scope of this



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   document is the interface between the battery charging controller and
   controlled batteries.

                 +-----------------------------------+
                 |         management system         |
                 +-----------------+-----------------+
                                   |
                                   | Battery MIB
                                   |
                 +-----------------+-----------------+
                 | managed element |                 |
                 |                 |                 |
                 |  +--------------+--------------+  |
                 |  | battery charging controller |  |
                 |  +-----+--------------+--------+  |
                 |        |              |           |
                 |  +-----+-----+        |           |
                 |  | internal  |        |           |
                 |  | battery   |        |           |
                 |  +-----------+        |           |
                 +-----------------------+-----------+
                                         |
                                   +-----+-----+
                                   | external  |
                                   | battery   |
                                   +-----------+

     Figure 1: Battery MIB as Interface between Management System and
         Battery-Charging Controller Supporting External Batteries

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in RFC
   2119 [RFC2119].

2.  The Internet-Standard Management Framework

   For a detailed overview of the documents that describe the current
   Internet-Standard Management Framework, please refer to section 7 of
   RFC 3410 [RFC3410].

   Managed objects are accessed via a virtual information store, termed
   the Management Information Base or MIB.  MIB objects are generally
   accessed through the Simple Network Management Protocol (SNMP).
   Objects in the MIB are defined using the mechanisms defined in the
   Structure of Management Information (SMI).  This memo specifies MIB
   modules that are compliant to the SMIv2, which is described in STD




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   58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58,RFC
   2580 [RFC2580].

3.  Design of the Battery MIB Module

3.1.  MIB Module Structure

   The Battery MIB module defined in this document defines objects for
   reporting information about batteries.  All managed objects providing
   information on the status of a battery are contained in a single
   table called "batteryTable".  The batteryTable contains one
   conceptual row per battery.

   Batteries are indexed by the entPhysicalIndex of the
   entPhysicalTable defined in the Entity MIB module [RFC6933].  An
   implementation of the Entity MIB module complying with the
   entity4CRCompliance MODULE-COMPLIANCE statement is required for
   compliant implementations of the Battery MIB module.

   If a battery is replaced, and the replacing battery uses the same
   physical connector as the replaced battery, then the replacing
   battery MUST be indexed with the same value of object
   entPhysicalIndex as the replaced battery.

   The kind of entity in the entPhysicalTable of the Entity MIB module
   is indicated by the value of enumeration object entPhysicalClass.
   All batteries SHOULD have the value of object entPhysicalClass set to
   battery(14) in their row of the entPhysicalTable.

   The batteryTable contains three groups of objects.  The first group
   (OIDs ending with 1-9) provides information on static properties of
   the battery.  The second group of objects (OIDs ending with 10-18)
   provides information on the current battery state, if it is charging
   or discharging, how much it is charged, its remaining capacity, the
   number of experienced charging cycles, etc.
















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      batteryTable(1)
      +--batteryEntry(1) [entPhysicalIndex]
         +-- r-n SnmpAdminString batteryIdentifier(1)
         +-- r-n SnmpAdminString batteryFirmwareVersion(2)
         +-- r-n Enumeration     batteryType(3)
         +-- r-n Unsigned32      batteryTechnology(4)
         +-- r-n Unsigned32      batteryDesignVoltage(5)
         +-- r-n Unsigned32      batteryNumberOfCells(6)
         +-- r-n Unsigned32      batteryDesignCapacity(7)
         +-- r-n Unsigned32      batteryMaxChargingCurrent(8)
         +-- r-n Unsigned32      batteryTrickleChargingCurrent(9)
         +-- r-n Unsigned32      batteryActualCapacity(10)
         +-- r-n Unsigned32      batteryChargingCycleCount(11)
         +-- r-n DateAndTime     batteryLastChargingCycleTime(12)
         +-- r-n Enumeration     batteryChargingOperState(13)
         +-- rwn Enumeration     batteryChargingAdminState(14)
         +-- r-n Unsigned32      batteryActualCharge(15)
         +-- r-n Unsigned32      batteryActualVoltage(16)
         +-- r-n Integer32       batteryActualCurrent(17)
         +-- r-n Integer32       batteryTemperature(18)
         +-- rwn Unsigned32      batteryAlarmLowCharge(19)
         +-- rwn Unsigned32      batteryAlarmLowVoltage(20)
         +-- rwn Unsigned32      batteryAlarmLowCapacity(21)
         +-- rwn Unsigned32      batteryAlarmHighCycleCount(22)
         +-- rwn Integer32       batteryAlarmHighTemperature(23)
         +-- rwn Integer32       batteryAlarmLowTemperature(24)
         +-- r-n SnmpAdminString batteryCellIdentifier(25)

   The third group of objects in this table (OIDs ending with 19-25) is
   used for notifications.  Threshold objects (OIDs ending with 19-24)
   indicate thresholds that can be used to raise an alarm if a property
   of the battery exceeds one of them.  Raising an alarm may include
   sending a notification.

   The Battery MIB defines seven notifications for indicating:

   1.  a battery-charging state change that was not triggered by writing
       to object batteryChargingAdminState,

   2.  a low-battery charging state,

   3.  a critical-battery state in which it cannot be used for power
       supply,

   4.  an aged battery that may need to be replaced,

   5.  a battery that has exceeded a temperature threshold,




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   6.  a battery that has been connected, and

   7.  disconnection of one or more batteries.

   Notifications 2-5 can use object batteryCellIdentifier to indicate a
   specific cell or a set of cells within the battery that have
   triggered the notification.

3.2.  Battery Technologies

   Static information in the batteryTable includes battery type and
   technology.  The battery type distinguishes primary (not
   rechargeable) batteries from rechargeable (secondary) batteries and
   capacitors.  The battery technology describes the actual technology
   of a battery, which typically is a chemical technology.

   Since battery technologies are the subject of intensive research and
   widely used technologies are often replaced by successor technologies
   within a few years, the list of battery technologies was not chosen
   as a fixed list.  Instead, IANA has created a registry for battery
   technologies at <http://www.iana.org/assignments/battery-
   technologies> where numbers are assigned to battery technologies.

   The table below shows battery technologies known today that are in
   commercial use with the numbers assigned to them by IANA.  New
   entries can be added to the IANA registry if new technologies are
   developed or if missing technologies are identified.  Note that there
   exists a huge number of battery types that are not listed in the IANA
   registry.  Many of them are experimental or cannot be used in an
   economically useful way.  New entries should be added to the IANA
   registry only if the respective technologies are in commercial use
   and relevant to standardized battery monitoring over the Internet.



















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      +--------------------------------+---------------+
      | Battery Technology             |      Value    |
      +--------------------------------+---------------+
      | Reserved                       |             0 |
      | Unknown                        |             1 |
      | Other                          |             2 |
      | Zinc-carbon                    |             3 |
      | Zinc chloride                  |             4 |
      | Nickel oxyhydroxide            |             5 |
      | Lithium-copper oxide           |             6 |
      | Lithium-iron disulfide         |             7 |
      | Lithium-manganese dioxide      |             8 |
      | Zinc-air                       |             9 |
      | Silver oxide                   |            10 |
      | Alkaline                       |            11 |
      | Lead-acid                      |            12 |
      | Valve-Regulated Lead-Acid, Gel |            13 |
      | Valve-Regulated Lead-Acid, AGM |            14 |
      | Nickel-cadmium                 |            15 |
      | Nickel-metal hydride           |            16 |
      | Nickel-zinc                    |            17 |
      | Lithium-ion                    |            18 |
      | Lithium polymer                |            19 |
      | Double layer capacitor         |            20 |
      | Unassigned                     | 21-4294967295 |
      +--------------------------------+---------------+

3.2.1.  Guidelines for Adding Battery Technologies

   New entries can be added to the IANA registry if new technologies are
   developed or if missing technologies are identified.  Note that there
   exists a huge number of battery types that are not listed in the IANA
   registry.  Many of them are experimental or cannot be used in an
   economically useful way.  New entries should be added to the IANA
   registry only if the respective technologies are in commercial use
   and relevant to standardized battery monitoring over the Internet.

3.3.  Battery Identification

   There are two identifiers to be used: the entPhysicalUUID defined in
   the Entity MIB [RFC6933] module and the batteryIdentifier defined in
   this module.  A battery is linked to an entPhysicalUUID through the
   shared entPhysicalIndex.

   The batteryIdentifier uniquely identifies the battery itself while
   the entPhysicalUUID identifies the slot of the device in which the
   battery is (currently) contained.  For a non-replaceable battery,
   both identifiers are always linked to the same physical battery.  But



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   for batteries that can be replaced, the identifiers have different
   functions.

   The entPhysicalUUID is always the same for a certain battery slot of
   a containing device even if the contained battery is replaced by
   another.  The batteryIdentifier is a representation of the battery
   identifier set by the battery manufacturer.  It is tied to the
   battery and usually cannot be changed.

   Many manufacturers deliver not just plain batteries but battery
   packages including additional hardware and firmware.  Typically,
   these modules include a battery identifier that can by retrieved by a
   device in which a battery has been installed.  The value of the
   object batteryIdentifier is an exact representation of this
   identifier.  The batteryIdentifier is useful when batteries are
   removed and reinstalled in the same device or in other devices.
   Then, the device or the network management system can trace batteries
   and achieve continuity of battery monitoring.

3.4.  Charging Cycles

   The lifetime of a battery can be approximated using the measure of
   charging cycles.  A commonly used definition of a charging cycle is
   the amount of discharge equal to the design (or nominal) capacity of
   the battery [SBS].  This means that a single charging cycle may
   include several steps of partial charging and discharging until the
   amount of discharging has reached the design capacity of the battery.
   After that, the next charging cycle immediately starts.

3.5.  Charge Control

   Managed object batteryChargingOperState indicates the current
   operational charging state of a battery and is a read-only object.
   For controlling the charging state, object batteryChargingAdminState
   can be used.  Writing to this object initiates a request to adapt the
   operational state according to the value that has been written.

   By default, the batteryChargingAdminState object is set to notSet(1).
   In this state, the charging controller is using its predefined
   policies to decide which operational state is suitable in the current
   situation.

   Setting the value of object batteryChargingAdminState may result in
   not changing the state of the battery to this value or even in
   setting the charging state to another value than the requested one.
   Due to operational conditions and limitations of the implementation
   of the Battery MIB module, changing the battery status according to a
   set value of object batteryChargingAdminState might not be possible.



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   For example, the charging controller might, at any time, decide to
   enter state discharging(5), if there is an operational need to use
   the battery for supplying power.

   The object batteryChargingAdminState will not automatically change
   when the object batteryChargingOperState changes.  If the operational
   state is changed, e.g., to the state discharging(5) due to
   operational conditions, the admin state will remain in its current
   state.  The charging controller SHOULD change the operational state
   to the state indicated by the object batteryChargingAdminState as
   soon as operational conditions allow this change.

   If a state change of the object batteryChargingAdminState is desired
   upon change of the operational state, the object
   batteryChargingOperState must be polled or the notification
   batteryChargingStateNotification must be used to get notified about
   the state change.  This could be used, e.g., if maintaining charge is
   not desired after fully charging a battery even if the charging
   controller and battery support it.  The object
   batteryChargingAdminState can then be set to doNotCharge(3) when the
   object batteryChargingOperState changes from charging(2) to
   maintainingCharge(3).  Another use case would be when performing
   several charge and discharge cycles for battery maintenance.

3.6.  Imported Definitions

   The BATTERY-MIB module defined in this document imports definitions
   from the following MIB modules: SNMPv2-SMI [RFC2578], SNMPv2-TC
   [RFC2579], SNMPv2-CONF [RFC2580], SNMP-FRAMEWORK-MIB [RFC3411], and
   ENTITY-MIB [RFC6933].

4.  Definitions

  BATTERY-MIB DEFINITIONS ::= BEGIN

  IMPORTS
      MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
      mib-2, Integer32, Unsigned32
          FROM SNMPv2-SMI                                -- RFC 2578
      DateAndTime
          FROM SNMPv2-TC                                 -- RFC 2579
      MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
          FROM SNMPv2-CONF                               -- RFC 2580
      SnmpAdminString
          FROM SNMP-FRAMEWORK-MIB                        -- RFC 3411
      entPhysicalIndex
          FROM ENTITY-MIB;                               -- RFC 6933




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  batteryMIB MODULE-IDENTITY
      LAST-UPDATED "201506150000Z"         -- 15 June 2015
      ORGANIZATION "IETF EMAN Working Group"
      CONTACT-INFO
          "General Discussion: eman@ietf.org
          To Subscribe: <http://www.ietf.org/mailman/listinfo/eman>
          Archive: <http://www.ietf.org/mail-archive/web/eman>

          Editor:
            Juergen Quittek
            NEC Europe, Ltd.
            NEC Laboratories Europe
            Kurfuersten-Anlage 36
            69115 Heidelberg
            Germany
            Tel: +49 6221 4342-115
            Email: quittek@neclab.eu"

      DESCRIPTION
          "This MIB module defines a set of objects for monitoring
          batteries of networked devices and of their components.

          Copyright (c) 2015 IETF Trust and the persons identified as
          authors of the code.  All rights reserved.

          Redistribution and use in source and binary forms, with or
          without modification, is permitted pursuant to, and subject
          to the license terms contained in, the Simplified BSD License
          set forth in Section 4.c of the IETF Trust's Legal Provisions
          Relating to IETF Documents
          (http://trustee.ietf.org/license-info).

          This version of this MIB module is part of RFC 7577; see
          the RFC itself for full legal notices."
  --  Revision history

      REVISION "201506150000Z"         -- 15 June 2015
      DESCRIPTION
          "Initial version published as RFC 7577."

      ::= { mib-2 233 }










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  --******************************************************************
  -- Top-Level Structure of the MIB Module
  --******************************************************************

  batteryNotifications OBJECT IDENTIFIER ::= { batteryMIB 0 }
  batteryObjects       OBJECT IDENTIFIER ::= { batteryMIB 1 }
  batteryConformance   OBJECT IDENTIFIER ::= { batteryMIB 2 }

  --==================================================================
  -- 1.  Object Definitions
  --==================================================================

  --------------------------------------------------------------------
  -- 1.1.  Battery Table
  --------------------------------------------------------------------
  batteryTable  OBJECT-TYPE
      SYNTAX      SEQUENCE OF BatteryEntry
      MAX-ACCESS  not-accessible
      STATUS      current
      DESCRIPTION
          "This table provides information on batteries.  It contains
          one conceptual row per battery in a managed entity.

          Batteries are indexed by the entPhysicalIndex of the
          entPhysicalTable defined in the ENTITY-MIB (RFC 6933).

          For implementations of the BATTERY-MIB, an implementation of
          the ENTITY-MIB complying with the entity4CRCompliance
          MODULE-COMPLIANCE statement of the ENTITY-MIB is required.

          If batteries are replaced, and the replacing battery uses
          the same physical connector as the replaced battery, then
          the replacing battery SHOULD be indexed with the same value
          of object entPhysicalIndex as the replaced battery."
      ::= { batteryObjects 1 }

  batteryEntry OBJECT-TYPE
      SYNTAX      BatteryEntry
      MAX-ACCESS  not-accessible
      STATUS      current
      DESCRIPTION
          "An entry providing information on a battery."
      INDEX  { entPhysicalIndex }
      ::= { batteryTable 1 }







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  BatteryEntry ::=
      SEQUENCE {
         batteryIdentifier               SnmpAdminString,
         batteryFirmwareVersion          SnmpAdminString,
         batteryType                     INTEGER,
         batteryTechnology               Unsigned32,
         batteryDesignVoltage            Unsigned32,
         batteryNumberOfCells            Unsigned32,
         batteryDesignCapacity           Unsigned32,
         batteryMaxChargingCurrent       Unsigned32,
         batteryTrickleChargingCurrent   Unsigned32,
         batteryActualCapacity           Unsigned32,
         batteryChargingCycleCount       Unsigned32,
         batteryLastChargingCycleTime    DateAndTime,
         batteryChargingOperState        INTEGER,
         batteryChargingAdminState       INTEGER,
         batteryActualCharge             Unsigned32,
         batteryActualVoltage            Unsigned32,
         batteryActualCurrent            Integer32,
         batteryTemperature              Integer32,
         batteryAlarmLowCharge           Unsigned32,
         batteryAlarmLowVoltage          Unsigned32,
         batteryAlarmLowCapacity         Unsigned32,
         batteryAlarmHighCycleCount      Unsigned32,
         batteryAlarmHighTemperature     Integer32,
         batteryAlarmLowTemperature      Integer32,
         batteryCellIdentifier           SnmpAdminString
      }

  batteryIdentifier OBJECT-TYPE
      SYNTAX      SnmpAdminString
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object contains an identifier for the battery.

          Many manufacturers deliver not only simple batteries but
          battery packages including additional hardware and firmware.
          Typically, these modules include an identifier that can be
          retrieved by a device in which a battery has been installed.
          The identifier is useful when batteries are removed and
          reinstalled in the same or other devices.  Then, the device
          or the network management system can trace batteries and
          achieve continuity of battery monitoring.

          If the battery is identified by more than one value,
          for example, by a model number and a serial number,
          then the value of this object is a concatenation of these



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          values, separated by the colon symbol ':'.  The values
          should be ordered so that a more significant value comes
          before a less significant one.  In the example above, the
          (more significant) model number would be first, and the serial
          number would follow: '<model number>:<serial number>'.

          If the battery identifier cannot be represented using the
          ISO/IEC IS 10646-1 character set, then a hexadecimal
          encoding of a binary representation of the entire battery
          identifier must be used.

          The value of this object must be an empty string if there
          is no battery identifier or if the battery identifier is
          unknown."
      ::= { batteryEntry 1 }

  batteryFirmwareVersion OBJECT-TYPE
      SYNTAX      SnmpAdminString
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object indicates the version number of the firmware
          that is included in a battery module.

          Many manufacturers deliver not pure batteries but battery
          packages including additional hardware and firmware.

          Since the behavior of the battery may change with the
          firmware, it may be useful to retrieve the firmware version
          number.

          The value of this object must be an empty string if there
          is no firmware or if the version number of the firmware is
          unknown."
      ::= { batteryEntry 2 }

  batteryType OBJECT-TYPE
      SYNTAX      INTEGER {
                      unknown(1),
                      other(2),
                      primary(3),
                      rechargeable(4),
                      capacitor(5)
                  }
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object indicates the type of battery.



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          It distinguishes between primary (not rechargeable)
          batteries, rechargeable (secondary) batteries, and
          capacitors.  Capacitors are not really batteries but
          are often used in the same way as a battery.

          The value other(2) can be used if the battery type is known
          but is none of the ones above.  Value unknown(1) is to be used
          if the type of battery cannot be determined."

      ::= { batteryEntry 3 }

  batteryTechnology OBJECT-TYPE
      SYNTAX      Unsigned32
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object indicates the technology used by the battery.
          Numbers identifying battery technologies are registered at
          IANA.  A current list of assignments can be found at
          <http://www.iana.org/assignments/battery-technologies>.

          Value unknown(1) MUST be used if the technology of the
          battery cannot be determined.

          Value other(2) can be used if the battery technology is known
          but is not one of the types already registered at IANA."
      ::= { batteryEntry 4 }

  batteryDesignVoltage OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "millivolt"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the design (or nominal) voltage of the
          battery in units of millivolt (mV).

          Note that the design voltage is a constant value and
          typically different from the actual voltage of the battery.

          A value of 0 indicates that the design voltage is unknown."
      ::= { batteryEntry 5 }

  batteryNumberOfCells OBJECT-TYPE
      SYNTAX      Unsigned32
      MAX-ACCESS  read-only
      STATUS      current




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      DESCRIPTION
          "This object indicates the number of cells contained in the
          battery.

          A value of 0 indicates that the number of cells is unknown."
      ::= { batteryEntry 6 }

  batteryDesignCapacity OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere hours"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the design (or nominal) capacity of
          the battery in units of milliampere hours (mAh).

          Note that the design capacity is a constant value and
          typically different from the actual capacity of the battery.
          Usually, this is a value provided by the manufacturer of the
          battery.

          A value of 0 indicates that the design capacity is
          unknown."
      ::= { batteryEntry 7 }

  batteryMaxChargingCurrent OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the maximum current to be used for
          charging the battery in units of milliampere (mA).

          Note that the maximum charging current may not lead to
          optimal charge of the battery and that some batteries can
          only be charged with the maximum current for a limited
          amount of time.

          A value of 0 indicates that the maximum charging current is
          unknown."
      ::= { batteryEntry 8 }

  batteryTrickleChargingCurrent OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere"
      MAX-ACCESS  read-only
      STATUS      current



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      DESCRIPTION
          "This object provides the recommended average current
          to be used for trickle charging the battery in units of
          mA.

          Typically, this is a value recommended by the manufacturer
          of the battery or by the manufacturer of the charging
          circuit.

          A value of 0 indicates that the recommended trickle charging
          current is unknown."
      ::= { batteryEntry 9 }

  batteryActualCapacity OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere hours"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the actual capacity of the
          battery in units of mAh.

          Typically, the actual capacity of a battery decreases
          with time and with usage of the battery.  It is usually
          lower than the design capacity.

          Note that the actual capacity needs to be measured and is
          typically an estimate based on observed discharging and
          charging cycles of the battery.

          A value of 'ffffffff'H indicates that the actual capacity
          cannot be determined."
      ::= { batteryEntry 10 }

  batteryChargingCycleCount OBJECT-TYPE
      SYNTAX      Unsigned32
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object indicates the number of completed charging
          cycles that the battery underwent.  In line with the
          Smart Battery Data Specification Revision 1.1, a charging
          cycle is defined as the process of discharging the battery
          by a total amount equal to the battery design capacity as
          given by object batteryDesignCapacity.  A charging cycle
          may include several steps of charging and discharging the
          battery until the discharging amount given by
          batteryDesignCapacity has been reached.  As soon as a



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          charging cycle has been completed, the next one starts
          immediately, independent of the battery's current charge at
          the end of the cycle.

          For batteries of type primary(3), the value of this object is
          always 0.

          A value of 'ffffffff'H indicates that the number of charging
          cycles cannot be determined."
      ::= { batteryEntry 11 }

  batteryLastChargingCycleTime OBJECT-TYPE
      SYNTAX      DateAndTime
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "The date and time of the last charging cycle.  The value
          '0000000000000000'H is returned if the battery has not been
          charged yet or if the last charging time cannot be
          determined.

          For batteries of type primary(1), the value of this object is
          always '0000000000000000'H."
      ::= { batteryEntry 12 }

  batteryChargingOperState OBJECT-TYPE
      SYNTAX      INTEGER {
                      unknown(1),
                      charging(2),
                      maintainingCharge(3),
                      noCharging(4),
                      discharging(5)
                  }
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object indicates the current charging state of the
          battery.

          Value unknown(1) indicates that the charging state of the
          battery cannot be determined.

          Value charging(2) indicates that the battery is being
          charged in a way such that the charge of the battery
          increases.

          Value maintainingCharge(3) indicates that the battery is
          being charged with a low-average current that compensates



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          self-discharging.  This includes trickle charging, float
          charging, and other methods for maintaining the current
          charge of a battery.  In typical implementations of charging
          controllers, state maintainingCharge(3) is only applied
          if the battery is fully charged or almost fully charged.

          Value noCharging(4) indicates that the battery is not being
          charged or discharged by electric current between the
          battery and electric circuits external to the battery.
          Note that the battery may still be subject to
          self-discharging.

          Value discharging(5) indicates that the battery is either
          used as the power source for electric circuits external to
          the battery or discharged intentionally by the
          charging controller, e.g., for the purpose of battery
          maintenance.  In any case, the charge of the battery
          decreases."
      ::= { batteryEntry 13 }

  batteryChargingAdminState OBJECT-TYPE
      SYNTAX      INTEGER {
                      notSet(1),
                      charge(2),
                      doNotCharge(3),
                      discharge(4)
                  }
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "The value of this object indicates the desired
          charging state of the battery.  The real state is
          indicated by object batteryChargingOperState.  See the
          definition of object batteryChargingOperState for a
          description of the values.

          When this object is initialized by an implementation of the
          BATTERY-MIB module, its value is set to notSet(1).  In this
          case, the charging controller is free to choose which
          operational state is suitable.

          When the batteryChargingAdminState object is set, then the
          BATTERY-MIB implementation must try to set the battery
          to the indicated state.  The result will be indicated by
          object batteryChargingOperState.

          Setting object batteryChargingAdminState to value notSet(1)
          is a request to the charging controller to operate



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          autonomously and choose the operational state that is
          suitable.

          Setting object batteryChargingAdminState to value charge(2)
          is a request to enter the operational state charging(2) until
          the battery is fully charged.  When the battery is fully
          charged, or if the battery was already fully charged or
          almost fully charged at the time of the request, the
          operational state will change to maintainingCharge(3) if the
          charging controller and the battery support the functionality
          of maintaining the charge, or it will change to noCharging(4)
          otherwise.

          Setting object batteryChargingAdminState to value
          doNotCharge(3) is a request for entering operational
          state noCharging(4).

          Setting object batteryChargingAdminState to value
          discharge(4) is a request for entering operational
          state discharging(5).  Discharging can be accomplished
          by ordinary use, applying a dedicated load, or any other
          means.  An example for applying this state is battery
          maintenance.  If the battery is empty or almost empty, the
          operational state will change to noCharging(4).
          The charging controller will decide which charge condition
          will be considered empty dependent on the battery
          technology used.  This is done to avoid damage on the
          battery due to deep discharge.

          Due to operational conditions and limitations of the
          implementation of the BATTERY-MIB module, changing the
          battery status according to a set value of object
          batteryChargingAdminState may not be possible.
          Setting the value of object batteryChargingAdminState
          may result in not changing the state of the battery
          to this value or even in setting the charging state
          to another value than the requested one.  For example,
          the charging controller might at any time decide to
          enter state discharging(5), if there is an operational need
          to use the battery for supplying power."
      ::= { batteryEntry 14 }

  batteryActualCharge OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere hours"
      MAX-ACCESS  read-only
      STATUS      current




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      DESCRIPTION
          "This object provides the actual charge of the battery
          in units of mAh.

          Note that the actual charge needs to be measured and is
          typically an estimate based on observed discharging and
          charging cycles of the battery.

          A value of 'ffffffff'H indicates that the actual charge
          cannot be determined."
      ::= { batteryEntry 15 }

  batteryActualVoltage OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "millivolt"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the actual voltage of the battery
          in units of mV.

          A value of 'ffffffff'H indicates that the actual voltage
          cannot be determined."
      ::= { batteryEntry 16 }

  batteryActualCurrent OBJECT-TYPE
      SYNTAX      Integer32
      UNITS       "milliampere"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "This object provides the actual charging or discharging
          current of the battery in units of mA.
          The charging current is represented by positive values,
          and the discharging current is represented by negative values.

          A value of '7fffffff'H indicates that the actual current
          cannot be determined."
      ::= { batteryEntry 17 }

  batteryTemperature OBJECT-TYPE
      SYNTAX      Integer32
      UNITS       "deci-degrees Celsius"
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "The ambient temperature at or within close proximity
          of the battery.



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          A value of '7fffffff'H indicates that the temperature
          cannot be determined."
      ::= { batteryEntry 18 }

  batteryAlarmLowCharge OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere hours"
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "This object provides the lower-threshold value for object
          batteryActualCharge.  If the value of object
          batteryActualCharge falls below this threshold,
          a low-battery alarm will be raised.  The alarm procedure may
          include generating a batteryLowNotification.

          This object should be set to a value such that when the
          batteryLowNotification is generated, the battery is still
          sufficiently charged to keep the device(s) that it powers
          operational for a time long enough to take actions before
          the powered device(s) enters a 'sleep' or 'off' state.

          A value of 0 indicates that no alarm will be raised for any
          value of object batteryActualVoltage."
      ::= { batteryEntry 19 }

    batteryAlarmLowVoltage OBJECT-TYPE
        SYNTAX      Unsigned32
        UNITS       "millivolt"
        MAX-ACCESS  read-write
        STATUS      current
        DESCRIPTION
            "This object provides the lower-threshold value for object
            batteryActualVoltage.  If the value of object
            batteryActualVoltage falls below this threshold,
            a low-battery alarm will be raised.  The alarm procedure may
            include generating a batteryLowNotification.

            This object should be set to a value such that when the
            batteryLowNotification is generated, the battery is still
            sufficiently charged to keep the device(s) that it powers
            operational for a time long enough to take actions before
            the powered device(s) enters a 'sleep' or 'off' state.

            A value of 0 indicates that no alarm will be raised for any
            value of object batteryActualVoltage."
        ::= { batteryEntry 20 }




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  batteryAlarmLowCapacity OBJECT-TYPE
      SYNTAX      Unsigned32
      UNITS       "milliampere hours"
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "This object provides the lower-threshold value for object
          batteryActualCapacity.  If the value of object
          batteryActualCapacity falls below this threshold,
          a battery aging alarm will be raised.  The alarm procedure
          may include generating a batteryAgingNotification.

          A value of 0 indicates that no alarm will be raised for any
          value of object batteryActualCapacity."
      ::= { batteryEntry 21 }

  batteryAlarmHighCycleCount OBJECT-TYPE
      SYNTAX      Unsigned32
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "This object provides the upper-threshold value for object
          batteryChargingCycleCount.  If the value of object
          batteryChargingCycleCount rises above this threshold,
          a battery aging alarm will be raised.  The alarm procedure
          may include generating a batteryAgingNotification.

          A value of 0 indicates that no alarm will be raised for any
          value of object batteryChargingCycleCount."
      ::= { batteryEntry 22 }

  batteryAlarmHighTemperature OBJECT-TYPE
      SYNTAX      Integer32
      UNITS       "deci-degrees Celsius"
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "This object provides the upper-threshold value for object
          batteryTemperature.  If the value of object
          batteryTemperature rises above this threshold, a battery
          high temperature alarm will be raised.  The alarm procedure
          may include generating a batteryTemperatureNotification.

          A value of '7fffffff'H indicates that no alarm will be
          raised for any value of object batteryTemperature."
      ::= { batteryEntry 23 }





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  batteryAlarmLowTemperature OBJECT-TYPE
      SYNTAX      Integer32
      UNITS       "deci-degrees Celsius"
      MAX-ACCESS  read-write
      STATUS      current
      DESCRIPTION
          "This object provides the lower-threshold value for object
          batteryTemperature.  If the value of object
          batteryTemperature falls below this threshold, a battery
          low temperature alarm will be raised.  The alarm procedure
          may include generating a batteryTemperatureNotification.

          A value of '7fffffff'H indicates that no alarm will be
          raised for any value of object batteryTemperature."
      ::= { batteryEntry 24 }

  batteryCellIdentifier OBJECT-TYPE
      SYNTAX      SnmpAdminString
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
          "The value of this object identifies one or more cells of a
          battery.  The format of the cell identifier may vary between
          different implementations.  It should uniquely identify one
          or more cells of the indexed battery.

          This object can be used for batteries, such as lithium
          polymer batteries for which battery controllers monitor
          cells individually.

          This object is used by notifications of types
          batteryLowNotification, batteryTemperatureNotification,
          batteryCriticalNotification, and batteryAgingNotification.
          These notifications can use the value of this object to
          indicate the event that triggered the generation of the
          notification in more detail by specifying a single cell
          or a set of cells within the battery that is specifically
          addressed by the notification.

          An example use case for this object is a single cell in a
          battery that exceeds the temperature indicated by object
          batteryAlarmHighTemperature.  In such a case, a
          batteryTemperatureNotification can be generated that not
          only indicates the battery for which the temperature limit
          has been exceeded but also the particular cell.

          The initial value of this object is the empty string.  The
          value of this object is set each time a



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          batteryLowNotification, batteryTemperatureNotification,
          batteryCriticalNotification, or batteryAgingNotification
          is generated.

          When a notification is generated that does not indicate a
          specific cell or set of cells, the value of this object is
          set to the empty string."
      ::= { batteryEntry 25 }

  --==================================================================
  -- 2.  Notifications
  --==================================================================

  batteryChargingStateNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryChargingOperState
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when a charging state
          of the battery (indicated by the value of object
          batteryChargingOperState) is triggered by an event other
          than a write action to object batteryChargingAdminState.
          Such an event may, for example, be triggered by a local
          battery controller."
      ::= { batteryNotifications 1 }

  batteryLowNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryActualCharge,
          batteryActualVoltage,
          batteryCellIdentifier
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when the current charge
          (batteryActualCharge) or the current voltage
          (batteryActualVoltage) of the battery falls below a
          threshold defined by object batteryAlarmLowCharge or object
          batteryAlarmLowVoltage, respectively.

          Note that, typically, this notification is generated in a
          state where the battery is still sufficiently charged to keep
          the device(s) that it powers operational for some time.
          If the charging state of the battery has become critical,
          i.e., the device(s) powered by the battery must go to a
          'sleep' or 'off' state, then the batteryCriticalNotification
          should be used instead.



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          If the low charge or voltage has been detected for a single
          cell or a set of cells of the battery and not for the entire
          battery, then object batteryCellIdentifier should be set to
          a value that identifies the cell or set of cells.
          Otherwise, the value of object batteryCellIdentifier should
          be set to the empty string when this notification is
          generated.

          The notification should not be sent again for the same
          battery or cell before either (a) the current voltage or
          the current charge, respectively, has become higher than the
          corresponding threshold through charging or (b) an indication
          of a maintenance action has been detected, such as a battery
          disconnection event or a reinitialization of the battery
          monitoring system.

          This notification should not be sent when the battery is in
          a charging mode, i.e., the value of object
          batteryChargingOperState is charging(2)."
      ::= { batteryNotifications 2 }

  batteryCriticalNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryActualCharge,
          batteryActualVoltage,
          batteryCellIdentifier
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when the current charge
          of the battery falls so low that it cannot provide a
          sufficient power supply function for regular operation
          of the powered device(s).  The battery needs to be charged
          before it can be used for regular power supply again.  The
          battery may still provide sufficient power for a 'sleep'
          mode of a powered device(s) or for a transition into an 'off'
          mode.

          If the critical state is caused by a single cell or a set of
          cells of the battery, then object batteryCellIdentifier
          should be set to a value that identifies the cell or set of
          cells.  Otherwise, the value of object batteryCellIdentifier
          should be set to the empty string when this notification is
          generated.

          The notification should not be sent again for the same
          battery before either the battery charge has increased
          through charging to a non-critical value or an indication



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          of a maintenance action has been detected, such as a battery
          disconnection event or a reinitialization of the battery
          monitoring system.

          This notification should not be sent when the battery is in
          a charging mode, i.e., the value of object
          batteryChargingOperState is charging(2)."
      ::= { batteryNotifications 3 }

  batteryTemperatureNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryTemperature,
          batteryCellIdentifier
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when the measured
          temperature (batteryTemperature) rises above the threshold
          defined by object batteryAlarmHighTemperature or falls
          below the threshold defined by object
          batteryAlarmLowTemperature.

          If the low or high temperature has been detected for a
          single cell or a set of cells of the battery and not for the
          entire battery, then object batteryCellIdentifier should be
          set to a value that identifies the cell or set of cells.
          Otherwise, the value of object batteryCellIdentifier should
          be set to the empty string when this notification is
          generated.

          It may occur that the temperature alternates between values
          slightly below and slightly above a threshold.  For limiting
          the notification rate in such a case, this notification
          should not be sent again for the same battery or cell,
          respectively, within a time interval of 10 minutes.

          An exception to the rate limitations occurs immediately
          after the reinitialization of the battery monitoring system.
          At this point in time, if the battery temperature is above
          the threshold defined by object batteryAlarmHighTemperature
          or below the threshold defined by object
          batteryAlarmLowTemperature, respectively, then this
          notification should be sent, independent of the time at
          which previous notifications for the same battery or cell,
          respectively, had been sent."
      ::= { batteryNotifications 4 }





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  batteryAgingNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryActualCapacity,
          batteryChargingCycleCount,
          batteryCellIdentifier
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when the actual
          capacity (batteryActualCapacity) falls below a threshold
          defined by object batteryAlarmLowCapacity
          or when the charging cycle count of the battery
          (batteryChargingCycleCount) exceeds the threshold defined
          by object batteryAlarmHighCycleCount.

          If the aging has been detected for a single cell or a set
          of cells of the battery and not for the entire battery, then
          object batteryCellIdentifier should be set to a value that
          identifies the cell or set of cells.  Otherwise, the value
          of object batteryCellIdentifier should be set to the empty
          string when this notification is generated.

          This notification should not be sent again for the same
          battery or cell, respectively, before an indication of a
          maintenance action has been detected, such as a battery
          disconnection event or a reinitialization of the battery
          monitoring system."
      ::= { batteryNotifications 5 }

  batteryConnectedNotification NOTIFICATION-TYPE
      OBJECTS     {
          batteryIdentifier
      }
      STATUS      current
      DESCRIPTION
          "This notification can be generated when it has been
          detected that a battery has been connected.  The battery
          can be identified by the value of object batteryIdentifier
          as well as by the value of index entPhysicalIndex that is
          contained in the OID of object batteryIdentifier."
      ::= { batteryNotifications 6 }

  batteryDisconnectedNotification NOTIFICATION-TYPE
      STATUS      current
      DESCRIPTION
          "This notification can be generated when it has been
          detected that one or more batteries have been disconnected."
      ::= { batteryNotifications 7 }



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  --==================================================================
  -- 3.  Conformance Information
  --==================================================================

  batteryCompliances OBJECT IDENTIFIER ::= { batteryConformance 1 }
  batteryGroups      OBJECT IDENTIFIER ::= { batteryConformance 2 }

  --------------------------------------------------------------------
  -- 3.1.  Compliance Statements
  --------------------------------------------------------------------

  batteryCompliance MODULE-COMPLIANCE
      STATUS      current
      DESCRIPTION
          "The compliance statement for implementations of the
          BATTERY-MIB module.

          A compliant implementation MUST implement the objects
          defined in the mandatory groups batteryDescriptionGroup
          and batteryStatusGroup.

          Note that this compliance statement requires
          compliance with the entity4CRCompliance
          MODULE-COMPLIANCE statement of the
          ENTITY-MIB (RFC 6933)."
      MODULE  -- this module
          MANDATORY-GROUPS {
              batteryDescriptionGroup,
              batteryStatusGroup
          }

          GROUP   batteryAlarmThresholdsGroup
          DESCRIPTION
             "A compliant implementation does not have to implement
              the batteryAlarmThresholdsGroup."

          GROUP   batteryNotificationsGroup
          DESCRIPTION
             "A compliant implementation does not have to implement
              the batteryNotificationsGroup."

          GROUP   batteryPerCellNotificationsGroup
          DESCRIPTION
             "A compliant implementation does not have to implement
              the batteryPerCellNotificationsGroup."

          GROUP   batteryAdminGroup
          DESCRIPTION



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             "A compliant implementation does not have to implement
              the batteryAdminGroup."

          OBJECT batteryAlarmLowCharge
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

          OBJECT batteryAlarmLowVoltage
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

          OBJECT batteryAlarmLowCapacity
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

          OBJECT batteryAlarmHighCycleCount
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

          OBJECT batteryAlarmHighTemperature
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

          OBJECT batteryAlarmLowTemperature
          MIN-ACCESS  read-only
          DESCRIPTION
              "A compliant implementation is not required
              to support set operations on this object."

      ::= { batteryCompliances 1 }

  --------------------------------------------------------------------
  -- 3.2.  MIB Grouping
  --------------------------------------------------------------------

  batteryDescriptionGroup OBJECT-GROUP
      OBJECTS {
         batteryIdentifier,



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         batteryFirmwareVersion,
         batteryType,
         batteryTechnology,
         batteryDesignVoltage,
         batteryNumberOfCells,
         batteryDesignCapacity,
         batteryMaxChargingCurrent,
         batteryTrickleChargingCurrent
      }
      STATUS      current
      DESCRIPTION
         "A compliant implementation MUST implement the objects
         contained in this group."
      ::= { batteryGroups 1 }

  batteryStatusGroup OBJECT-GROUP
      OBJECTS {
         batteryActualCapacity,
         batteryChargingCycleCount,
         batteryLastChargingCycleTime,
         batteryChargingOperState,
         batteryActualCharge,
         batteryActualVoltage,
         batteryActualCurrent,
         batteryTemperature
      }
      STATUS      current
      DESCRIPTION
         "A compliant implementation MUST implement the objects
         contained in this group."
      ::= { batteryGroups 2 }

  batteryAdminGroup OBJECT-GROUP
      OBJECTS {
         batteryChargingAdminState
      }
      STATUS      current
      DESCRIPTION
         "A compliant implementation does not have to implement the
         object contained in this group."
      ::= { batteryGroups 3 }

  batteryAlarmThresholdsGroup OBJECT-GROUP
      OBJECTS {
         batteryAlarmLowCharge,
         batteryAlarmLowVoltage,
         batteryAlarmLowCapacity,
         batteryAlarmHighCycleCount,



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         batteryAlarmHighTemperature,
         batteryAlarmLowTemperature
      }
      STATUS      current
      DESCRIPTION
         "A compliant implementation does not have to implement the
         objects contained in this group."
      ::= { batteryGroups 4 }

  batteryNotificationsGroup NOTIFICATION-GROUP
      NOTIFICATIONS {
         batteryChargingStateNotification,
         batteryLowNotification,
         batteryCriticalNotification,
         batteryAgingNotification,
         batteryTemperatureNotification,
         batteryConnectedNotification,
         batteryDisconnectedNotification
      }
      STATUS      current
      DESCRIPTION
          "A compliant implementation does not have to implement the
          notifications contained in this group."
      ::= { batteryGroups 5 }

  batteryPerCellNotificationsGroup OBJECT-GROUP
      OBJECTS {
         batteryCellIdentifier
      }
      STATUS      current
      DESCRIPTION
          "A compliant implementation does not have to implement the
          object contained in this group."
      ::= { batteryGroups 6 }
  END

5.  Security Considerations

   There are a number of management objects defined in this MIB module
   with a MAX-ACCESS clause of read-write.  Such objects may be
   considered sensitive or vulnerable in some network environments.  The
   support for SET operations in a non-secure environment without proper
   protection opens devices to attack.  These are the tables and objects
   and their sensitivity/vulnerability:

   o  batteryChargingAdminState:
      Setting the battery charging state can be beneficial for an
      operator for various reasons such as charging batteries when the



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      price of electricity is low.  However, setting the charging state
      can be used by an attacker to discharge batteries of devices and
      thereby switching these devices off if they are powered solely by
      batteries.  In particular, if the batteryAlarmLowCharge and
      batteryAlarmLowVoltage can also be set, this attack will go
      unnoticed (i.e., no notifications are sent).

   o  batteryAlarmLowCharge and batteryAlarmLowVoltage:
      These objects set the threshold for an alarm to be raised when the
      battery charge or voltage falls below the corresponding one of
      them.  An attacker setting one of these alarm values can switch
      off the alarm by setting it to the 'off' value 0, or it can modify
      the alarm behavior by setting it to any other value.  The result
      may be loss of data if the battery runs empty without warning to a
      recipient expecting such a notification.

   o  batteryAlarmLowCapacity and batteryAlarmHighCycleCount:
      These objects set the threshold for an alarm to be raised when the
      battery becomes older and less performant than required for stable
      operation.  An attacker setting this alarm value can switch off
      the alarm by setting it to the 'off' value 0 or modify the alarm
      behavior by setting it to any other value.  This may lead to
      either a costly replacement of a working battery or use of
      batteries that are too old or too weak.  The consequence of the
      latter could be that, e.g., a battery cannot provide power long
      enough between two scheduled charging actions causing the powered
      device to shut down and potentially lose data.

   o  batteryAlarmHighTemperature and batteryAlarmLowTemperature:
      These objects set thresholds for an alarm to be raised when the
      battery rises above / falls below them.  An attacker setting one
      of these alarm values can switch off these alarms by setting them
      to the 'off' value '7fffffff'H, or it can modify the alarm
      behavior by setting them to any other value.  The result may be,
      e.g., an unnecessary shutdown of a device if
      batteryAlarmHighTemperature is set too low, there is damage to the
      device by temperatures that are too high if switched off or set to
      values that are too high, or there is damage to the battery when,
      e.g., it is being charged.  Batteries can also be damaged, e.g.,
      in an attempt to charge them at temperatures that are too low.

   Some of the readable objects in this MIB module (i.e., objects with a
   MAX-ACCESS other than not-accessible) may be considered sensitive or
   vulnerable in some network environments.  It is thus important to
   control even GET and/or NOTIFY access to these objects and possibly
   to even encrypt the values of these objects when sending them over
   the network via SNMP.  These are the tables and objects and their
   sensitivity/vulnerability:



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   All potentially sensible or vulnerable objects of this MIB module are
   in the batteryTable.  In general, there are no serious operational
   vulnerabilities foreseen in case of an unauthorized read access to
   this table.  However, corporate confidentiality issues need to be
   considered.  The following information or parts of it might be a
   trade secret:

   o  the number of batteries installed in a managed node (batteryIndex)

   o  properties of these batteries (batteryActualCapacity and
      batteryChargingCycleCount)

   o  the time at which the next replacement cycle for batteries can be
      expected (batteryAlarmLowCapacity and batteryAlarmHighCycleCount)

   o  the types of batteries in use and their firmware versions
      (batteryIdentifier, batteryFirmwareVersion, batteryType, and
      batteryTechnology)

   For any battery-powered device whose use can be correlated to an
   individual or a small group of individuals, the following objects
   have the potential to reveal information about those individuals'
   activities or habits (e.g., if they are near a power outlet, if they
   have been using their devices heavily, etc.):

   o  batteryChargingCycleCount

   o  batteryLastChargingCycleTime

   o  batteryChargingOperState

   o  batteryActualCharge

   o  batteryActualVoltage

   o  batteryActualCurrent

   o  batteryTemperature

   o  batteryAlarmLowCharge

   o  batteryAlarmLowVoltage

   o  batteryAlarmLowCapacity

   o  batteryAlarmHighCycleCount

   o  batteryAlarmHighTemperature



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   o  batteryAlarmLowTemperature

   Implementers of this specification should use appropriate privacy
   protections as discussed in Section 9 of "Requirements for Energy
   Management" [RFC6988].  Battery monitoring of devices used by
   individuals or in homes should only occur with proper authorization.

   SNMP versions prior to SNMPv3 did not include adequate security.
   Even if the network itself is secure (for example by using IPsec),
   there is no control as to who on the secure network is allowed to
   access and GET/SET (read/change/create/delete) the objects in this
   MIB module.

   Implementations SHOULD provide the security features described by the
   SNMPv3 framework (see [RFC3410]), and implementations claiming
   compliance to the SNMPv3 standard MUST include full support for
   authentication and privacy via the User-based Security Model (USM)
   [RFC3414] with the AES cipher algorithm [RFC3826].  Implementations
   MAY also provide support for the Transport Security Model (TSM)
   [RFC5591] in combination with a secure transport such as SSH
   [RFC5592] or TLS/DTLS [RFC6353].

   Further, deployment of SNMP versions prior to SNMPv3 is NOT
   RECOMMENDED.  Instead, it is RECOMMENDED to deploy SNMPv3 and to
   enable cryptographic security.  It is then a customer/operator
   responsibility to ensure that the SNMP entity giving access to an
   instance of this MIB module is properly configured to give access to
   the objects only to those principals (users) that have legitimate
   rights to indeed GET or SET (change/create/delete) them.

6.  IANA Considerations

6.1.  SMI Object Identifier Registration

   The Battery MIB module defined in this document uses the following
   IANA-assigned OBJECT IDENTIFIER value recorded in the SMI Numbers
   registry:

             Descriptor        OBJECT IDENTIFIER value
             ----------        -----------------------
             batteryMIB        { mib-2 233 }

6.2.  Battery Technology Registration

   Object batteryTechnology defined in Section 4 reports battery
   technologies.  Eighteen values for battery technologies have
   initially been defined.  They are listed in a table in Section 3.2.




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   For ensuring extensibility of this list, IANA has created a registry
   for battery technologies at <http://www.iana.org/assignments/battery-
   technologies> and filled it with the initial list given in
   Section 3.2.

   New assignments of numbers for battery technologies will be
   administered by IANA through Expert Review [RFC5226].  Experts must
   check for sufficient relevance of a battery technology to be added
   according to the guidelines in Section 3.2.1.

7.  References

7.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC2578]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Structure of Management Information
              Version 2 (SMIv2)", STD 58, RFC 2578,
              DOI 10.17487/RFC2578, April 1999,
              <http://www.rfc-editor.org/info/rfc2578>.

   [RFC2579]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Textual Conventions for SMIv2",
              STD 58, RFC 2579, DOI 10.17487/RFC2579, April 1999,
              <http://www.rfc-editor.org/info/rfc2579>.

   [RFC2580]  McCloghrie, K., Ed., Perkins, D., Ed., and J.
              Schoenwaelder, Ed., "Conformance Statements for SMIv2",
              STD 58, RFC 2580, DOI 10.17487/RFC2580, April 1999,
              <http://www.rfc-editor.org/info/rfc2580>.

   [RFC3411]  Harrington, D., Presuhn, R., and B. Wijnen, "An
              Architecture for Describing Simple Network Management
              Protocol (SNMP) Management Frameworks", STD 62, RFC 3411,
              DOI 10.17487/RFC3411, December 2002,
              <http://www.rfc-editor.org/info/rfc3411>.

   [RFC3414]  Blumenthal, U. and B. Wijnen, "User-based Security Model
              (USM) for version 3 of the Simple Network Management
              Protocol (SNMPv3)", STD 62, RFC 3414,
              DOI 10.17487/RFC3414, December 2002,
              <http://www.rfc-editor.org/info/rfc3414>.





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   [RFC3826]  Blumenthal, U., Maino, F., and K. McCloghrie, "The
              Advanced Encryption Standard (AES) Cipher Algorithm in the
              SNMP User-based Security Model", RFC 3826,
              DOI 10.17487/RFC3826, June 2004,
              <http://www.rfc-editor.org/info/rfc3826>.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              DOI 10.17487/RFC5226, May 2008,
              <http://www.rfc-editor.org/info/rfc5226>.

   [RFC5591]  Harrington, D. and W. Hardaker, "Transport Security Model
              for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 5591, DOI 10.17487/RFC5591, June 2009,
              <http://www.rfc-editor.org/info/rfc5591>.

   [RFC5592]  Harrington, D., Salowey, J., and W. Hardaker, "Secure
              Shell Transport Model for the Simple Network Management
              Protocol (SNMP)", RFC 5592, DOI 10.17487/RFC5592, June
              2009, <http://www.rfc-editor.org/info/rfc5592>.

   [RFC6353]  Hardaker, W., "Transport Layer Security (TLS) Transport
              Model for the Simple Network Management Protocol (SNMP)",
              STD 78, RFC 6353, DOI 10.17487/RFC6353, July 2011,
              <http://www.rfc-editor.org/info/rfc6353>.

   [RFC6933]  Bierman, A., Romascanu, D., Quittek, J., and M.
              Chandramouli, "Entity MIB (Version 4)", RFC 6933,
              DOI 10.17487/RFC6933, May 2013,
              <http://www.rfc-editor.org/info/rfc6933>.

7.2.  Informative References

   [RFC1628]  Case, J., Ed., "UPS Management Information Base",
              RFC 1628, DOI 10.17487/RFC1628, May 1994,
              <http://www.rfc-editor.org/info/rfc1628>.

   [RFC3410]  Case, J., Mundy, R., Partain, D., and B. Stewart,
              "Introduction and Applicability Statements for Internet-
              Standard Management Framework", RFC 3410,
              DOI 10.17487/RFC3410, December 2002,
              <http://www.rfc-editor.org/info/rfc3410>.

   [RFC6988]  Quittek, J., Ed., Chandramouli, M., Winter, R., Dietz, T.,
              and B. Claise, "Requirements for Energy Management",
              RFC 6988, DOI 10.17487/RFC6988, September 2013,
              <http://www.rfc-editor.org/info/rfc6988>.




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   [RFC7326]  Parello, J., Claise, B., Schoening, B., and J. Quittek,
              "Energy Management Framework", RFC 7326,
              DOI 10.17487/RFC7326, September 2014,
              <http://www.rfc-editor.org/info/rfc7326>.

   [RFC7460]  Chandramouli, M., Claise, B., Schoening, B., Quittek, J.,
              and T. Dietz, "Monitoring and Control MIB for Power and
              Energy", RFC 7460, DOI 10.17487/RFC7460, March 2015,
              <http://www.rfc-editor.org/info/rfc7460>.

   [SBS]      "Smart Battery Data Specification", Revision 1.1, December
              1998.







































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Acknowledgements

   We would like to thank Steven Chew, Bill Mielke, and Alan Luchuk for
   their valuable input.

Authors' Addresses

   Juergen Quittek
   NEC Europe, Ltd.
   NEC Laboratories Europe
   Network Research Division
   Kurfuersten-Anlage 36
   Heidelberg  69115
   Germany

   Phone: +49 6221 4342-115
   Email: quittek@neclab.eu


   Rolf Winter
   NEC Europe, Ltd.
   NEC Laboratories Europe
   Network Research Division
   Kurfuersten-Anlage 36
   Heidelberg  69115
   Germany

   Phone: +49 6221 4342-121
   Email: Rolf.Winter@neclab.eu


   Thomas Dietz
   NEC Europe, Ltd.
   NEC Laboratories Europe
   Network Research Division
   Kurfuersten-Anlage 36
   Heidelberg  69115
   Germany

   Phone: +49 6221 4342-128
   Email: Thomas.Dietz@neclab.eu










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