Module Name: src
Committed By: jruoho
Date: Wed Mar 17 17:16:43 UTC 2010
Modified Files:
src/share/man/man4: acpibat.4
Log Message:
Try to document this in a little more verbose manner.
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/share/man/man4/acpibat.4
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man4/acpibat.4
diff -u src/share/man/man4/acpibat.4:1.7 src/share/man/man4/acpibat.4:1.8
--- src/share/man/man4/acpibat.4:1.7 Mon May 4 19:17:49 2009
+++ src/share/man/man4/acpibat.4 Wed Mar 17 17:16:43 2010
@@ -1,6 +1,6 @@
-.\" $NetBSD: acpibat.4,v 1.7 2009/05/04 19:17:49 wiz Exp $
+.\" $NetBSD: acpibat.4,v 1.8 2010/03/17 17:16:43 jruoho Exp $
.\"
-.\" Copyright (c) 2002, 2004 The NetBSD Foundation, Inc.
+.\" Copyright (c) 2002, 2004, 2010 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
@@ -24,30 +24,66 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd September 4, 2007
+.Dd March 17, 2010
.Dt ACPIBAT 4
.Os
.Sh NAME
.Nm acpibat
-.Nd ACPI Control Method Battery
+.Nd ACPI Battery
.Sh SYNOPSIS
.Cd "acpibat* at acpi?"
.Sh DESCRIPTION
The
.Nm
-driver supports ACPI Control Method Battery.
+driver supports
+.Tn ACPI
+batteries.
.Pp
-The status can be monitored by
+The battery status is made available through the
.Xr envsys 4
-API or
+.Tn API .
+The battery information can be displayed also with the
.Xr envstat 8
-command.
+command:
+.Bd -literal -offset 2n
+$ 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
+.Ed
+.Pp
+Depending on the battery, the unit of measurement is either watt-hour
+.Tn Pq Wh
+or ampere hour
+.Tn Pq Ah
+for the capacity related information.
+From these the
+.Dq charge
+is usually the most interesting value,
+but it is possible to derive useful information also from the other values.
+For example, when
+.Xr acpiacad 4
+is disconnected, the
+.Dq discharge rate
+gives a coarse approximation of the current power consumption.
+The ratio between design capacity and last full capacity on the other hand
+reveals the overall
+.Dq health
+of deteriorating lithium-ion batteries.
.Sh EVENTS
The
.Nm
driver is able to send events to
.Xr powerd 8
-when capacity state has been changed.
+daemon when a capacity state has been changed.
The new state will be reported as the
.Em fourth
argument to the
@@ -68,8 +104,20 @@
.Sh HISTORY
The
.Nm
-driver
-appeared in
+driver appeared in
.Nx 1.6 .
.Sh BUGS
-Smart Battery Specification-based batteries are not supported.
+The
+.Tn ACPI
+specifications make a distinction between
+.Dq control method batteries
+and
+.Dq smart batteries .
+The
+.Nm
+driver only supports control method batteries.
+Furthermore,
+.Nm
+does not yet support some additional battery information introduced in the
+.Tn ACPI 4.0
+standard.
