ACPIBAT(4) | Device Drivers Manual | ACPIBAT(4) |
acpibat
—
acpibat* at acpi?
acpibat
driver supports ACPI batteries.
The battery status is made available through the envsys(4) API. The battery information can be displayed also with the envstat(8) command:
$ envstat -d acpibat0 Current CritMax WarnMax WarnMin CritMin Unit present: ON design voltage: 14.400 V voltage: 16.267 V design cap: 74.880 Wh last full cap: 48.260 Wh charge: 47.910 5.000% 0.414% Wh (99.27%) charge rate: N/A discharge rate: 16.641 W charging: OFF charge state: NORMAL
Depending on the battery, the unit of measurement is either watt-hour (Wh) or ampere-hour (Ah) for the capacity related information. From these the “charge” is usually the most interesting value, but it is possible to derive useful information also from the other values. For example, when acpiacad(4) is disconnected, the “discharge rate” gives a coarse approximation of the current power consumption. The ratio between the design capacity and the last full capacity on the other hand reveals the overall “health” of deteriorating lithium-ion batteries.
acpibat
driver is able to send events to
powerd(8) daemon when a capacity
state has been changed. The new state will be reported as the
fourth argument to the
/etc/powerd/scripts/sensor_battery script. If a custom
capacity limit was set via
envstat(8), the
acpibat
driver will report a
user-capacity event to the same script when current capacity
limit has been reached.
acpibat
driver appeared in NetBSD
1.6.
acpibat
driver only supports control method batteries.
Furthermore, acpibat
does not yet support some
additional battery information introduced in the ACPI 4.0 standard.
March 17, 2010 | NetBSD 9.4 |