1.\" $NetBSD: acpibat.4,v 1.9 2010/03/25 15:34:30 jruoho Exp $ 2.\" 3.\" Copyright (c) 2002, 2004, 2010 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 15.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 16.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25.\" POSSIBILITY OF SUCH DAMAGE. 26.\" 27.Dd March 17, 2010 28.Dt ACPIBAT 4 29.Os 30.Sh NAME 31.Nm acpibat 32.Nd ACPI Battery 33.Sh SYNOPSIS 34.Cd "acpibat* at acpi?" 35.Sh DESCRIPTION 36The 37.Nm 38driver supports 39.Tn ACPI 40batteries. 41.Pp 42The battery status is made available through the 43.Xr envsys 4 44.Tn API . 45The battery information can be displayed also with the 46.Xr envstat 8 47command: 48.Bd -literal -offset 2n 49$ envstat -d acpibat0 50 Current CritMax WarnMax WarnMin CritMin Unit 51 present: ON 52design voltage: 14.400 V 53 voltage: 16.267 V 54 design cap: 74.880 Wh 55 last full cap: 48.260 Wh 56 charge: 47.910 5.000% 0.414% Wh (99.27%) 57 charge rate: N/A 58discharge rate: 16.641 W 59 charging: OFF 60 charge state: NORMAL 61.Ed 62.Pp 63Depending on the battery, the unit of measurement is either watt-hour 64.Tn Pq Wh 65or ampere-hour 66.Tn Pq Ah 67for the capacity related information. 68From these the 69.Dq charge 70is usually the most interesting value, 71but it is possible to derive useful information also from the other values. 72For example, when 73.Xr acpiacad 4 74is disconnected, the 75.Dq discharge rate 76gives a coarse approximation of the current power consumption. 77The ratio between the design capacity and the last full capacity 78on the other hand reveals the overall 79.Dq health 80of deteriorating lithium-ion batteries. 81.Sh EVENTS 82The 83.Nm 84driver is able to send events to 85.Xr powerd 8 86daemon when a capacity state has been changed. 87The new state will be reported as the 88.Em fourth 89argument to the 90.Pa /etc/powerd/scripts/sensor_battery 91script. 92If a custom capacity limit was set via 93.Xr envstat 8 , 94the 95.Nm 96driver will report a 97.Em user-capacity 98event to the same script when current capacity limit has been reached. 99.Sh SEE ALSO 100.Xr acpi 4 , 101.Xr envsys 4 , 102.Xr envstat 8 , 103.Xr powerd 8 104.Sh HISTORY 105The 106.Nm 107driver appeared in 108.Nx 1.6 . 109.Sh BUGS 110The 111.Tn ACPI 112specifications make a distinction between 113.Dq control method batteries 114and 115.Dq smart batteries . 116The 117.Nm 118driver only supports control method batteries. 119Furthermore, 120.Nm 121does not yet support some additional battery information introduced in the 122.Tn ACPI 4.0 123standard. 124