1Battery Characteristics
2
3The devicetree battery node provides static battery characteristics.
4In smart batteries, these are typically stored in non-volatile memory
5on a fuel gauge chip. The battery node should be used where there is
6no appropriate non-volatile memory, or it is unprogrammed/incorrect.
7
8Upstream dts files should not include battery nodes, unless the battery
9represented cannot easily be replaced in the system by one of a
10different type. This prevents unpredictable, potentially harmful,
11behavior should a replacement that changes the battery type occur
12without a corresponding update to the dtb.
13
14Required Properties:
15 - compatible: Must be "simple-battery"
16
17Optional Properties:
18 - voltage-min-design-microvolt: drained battery voltage
19 - energy-full-design-microwatt-hours: battery design energy
20 - charge-full-design-microamp-hours: battery design capacity
21 - precharge-current-microamp: current for pre-charge phase
22 - charge-term-current-microamp: current for charge termination phase
23 - constant-charge-current-max-microamp: maximum constant input current
24 - constant-charge-voltage-max-microvolt: maximum constant input voltage
25
26Battery properties are named, where possible, for the corresponding
27elements in enum power_supply_property, defined in
28https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/power_supply.h
29
30Batteries must be referenced by chargers and/or fuel-gauges
31using a phandle. The phandle's property should be named
32"monitored-battery".
33
34Example:
35
36	bat: battery {
37		compatible = "simple-battery";
38		voltage-min-design-microvolt = <3200000>;
39		energy-full-design-microwatt-hours = <5290000>;
40		charge-full-design-microamp-hours = <1430000>;
41		precharge-current-microamp = <256000>;
42		charge-term-current-microamp = <128000>;
43		constant-charge-current-max-microamp = <900000>;
44		constant-charge-voltage-max-microvolt = <4200000>;
45	};
46
47	charger: charger@11 {
48		....
49		monitored-battery = <&bat>;
50		...
51	};
52
53	fuel_gauge: fuel-gauge@22 {
54		....
55		monitored-battery = <&bat>;
56		...
57	};
58