| Battery Characteristics |
| |
| The devicetree battery node provides static battery characteristics. |
| In smart batteries, these are typically stored in non-volatile memory |
| on a fuel gauge chip. The battery node should be used where there is |
| no appropriate non-volatile memory, or it is unprogrammed/incorrect. |
| |
| Upstream dts files should not include battery nodes, unless the battery |
| represented cannot easily be replaced in the system by one of a |
| different type. This prevents unpredictable, potentially harmful, |
| behavior should a replacement that changes the battery type occur |
| without a corresponding update to the dtb. |
| |
| Required Properties: |
| - compatible: Must be "simple-battery" |
| |
| Optional Properties: |
| - voltage-min-design-microvolt: drained battery voltage |
| - energy-full-design-microwatt-hours: battery design energy |
| - charge-full-design-microamp-hours: battery design capacity |
| - precharge-current-microamp: current for pre-charge phase |
| - charge-term-current-microamp: current for charge termination phase |
| - constant-charge-current-max-microamp: maximum constant input current |
| - constant-charge-voltage-max-microvolt: maximum constant input voltage |
| |
| Battery properties are named, where possible, for the corresponding |
| elements in enum power_supply_property, defined in |
| https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h |
| |
| Batteries must be referenced by chargers and/or fuel-gauges |
| using a phandle. The phandle's property should be named |
| "monitored-battery". |
| |
| Example: |
| |
| bat: battery { |
| compatible = "simple-battery"; |
| voltage-min-design-microvolt = <3200000>; |
| energy-full-design-microwatt-hours = <5290000>; |
| charge-full-design-microamp-hours = <1430000>; |
| precharge-current-microamp = <256000>; |
| charge-term-current-microamp = <128000>; |
| constant-charge-current-max-microamp = <900000>; |
| constant-charge-voltage-max-microvolt = <4200000>; |
| }; |
| |
| charger: charger@11 { |
| .... |
| monitored-battery = <&bat>; |
| ... |
| }; |
| |
| fuel_gauge: fuel-gauge@22 { |
| .... |
| monitored-battery = <&bat>; |
| ... |
| }; |