dmi_battery

Synopsis

#include <opendmi/entity/battery.h>

typedef struct dmi_battery {
    const char *location;
    const char *vendor;
    dmi_date_t manufacture_date;
    const char *manufacture_date_string;
    const char *serial_number;
    const char *name;
    dmi_battery_chemistry_t chemistry;
    unsigned int capacity;
    unsigned short design_capacity;
    unsigned short voltage;
    const char *sbds_version;
    unsigned short maximum_error;
    uint16_t sbds_serial_number;
    dmi_date_t sbds_manufacture_date;
    const char *sbds_chemistry;
    uint8_t design_capacity_multiplier;
    uint32_t oem_defined;
} dmi_battery_t;

Description

The dmi_battery_t structure holds a decoded portable battery structure (type 22) of SMBIOS: the static attributes of a battery pack of a portable system, such as its maker, chemistry, capacity and voltage. There is one structure for each battery pack.

Smart batteries, which follow the Smart Battery Data Specification (SBDS), may leave the manufacture date, serial number and chemistry of the structure empty, and give them in the sbds_ fields instead. The decoder combines both for the manufacture date and the capacity.

The structure is returned by dmi_entity_info for the structures of type DMI_TYPE(portable_battery), and lives as long as the context it has been decoded in.

Fields

location

Where the battery is, for example "in the back, on the left-hand side", or nullptr if not given.

vendor

Name of the manufacturer of the battery, or nullptr if not given.

manufacture_date

Date the battery was made on: the date manufacture_date_string spells, or sbds_manufacture_date when the string is missing or cannot be parsed. DMI_DATE_NONE if neither gives a date.

manufacture_date_string

Manufacture date as the structure spells it, expected in the MM/DD/YY or MM/DD/YYYY format, or nullptr if not given, as smart batteries do.

serial_number

Serial number of the battery, or nullptr if not given, as smart batteries do (see sbds_serial_number).

name

Name of the battery device, for example "DR-36", or nullptr if not given.

chemistry

Chemistry of the battery. Smart batteries set it to DMI_BATTERY_CHEMISTRY_UNKNOWN, and give it in sbds_chemistry.

capacity

Design capacity of the battery, in milliwatt-hours: design_capacity times design_capacity_multiplier. 0 if unknown.

design_capacity

Design capacity as the structure carries it, in units of design_capacity_multiplier milliwatt-hours. 0 if unknown.

voltage

Design voltage of the battery, in millivolts, or 0 if unknown.

sbds_version

Version of the Smart Battery Data Specification the battery supports, or nullptr if it supports none.

maximum_error

Upper bound of the error of the energy the battery reports, as a percentage from 0 to 100, or USHRT_MAX if unknown.

sbds_serial_number

Serial number of a smart battery, which identifies it together with the manufacturer, the device name and the manufacture date. It is meaningful only when serial_number is nullptr. Present since SMBIOS 2.2; 0 in older structures.

sbds_manufacture_date

Manufacture date of a smart battery, decoded from the packed SBDS format. It is meaningful only when manufacture_date_string is nullptr. DMI_DATE_NONE if the structure carries none. Present since SMBIOS 2.2.

sbds_chemistry

Chemistry of a smart battery, for example "PbAc", or nullptr if not given. It is meaningful only when chemistry is DMI_BATTERY_CHEMISTRY_UNKNOWN. Present since SMBIOS 2.2.

design_capacity_multiplier

Factor the design capacity is multiplied by, which smart battery implementations set to 10. Present since SMBIOS 2.2; 1 in older structures.

oem_defined

Information specific to the OEM or to the firmware vendor. Present since SMBIOS 2.2; 0 in older structures.

Examples

dmi_registry_t *registry = dmi_get_registry(context);
dmi_entity_t   *entity   =
        dmi_registry_lookup_first(registry, DMI_TYPE(portable_battery),
                                  true);
dmi_battery_t  *battery  =
        dmi_entity_info(entity, DMI_TYPE(portable_battery));

if (battery != nullptr) {
    const char *chemistry = battery->sbds_chemistry;

    if (battery->chemistry != DMI_BATTERY_CHEMISTRY_UNKNOWN)
        chemistry = dmi_battery_chemistry_name(battery->chemistry);

    printf("%s: %u mWh, %s\n", battery->name ? battery->name : "Battery",
           battery->capacity, chemistry ? chemistry : "unknown");
}

See also

dmi_entity_info, dmi_battery_chemistry

Standards

DMTF SMBIOS Specification (DSP0134), version 2.1 or newer.