[ltp] Aggressive battery diagnostics on T42p, should I return these?

[David A. Desrosiers]

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	Ever since Day 1 of using my shiny new T42p (bought new, direct from
IBM), I have had pretty horrible battery life on the unit. When I bought
it, I was told that the "extended" battery was the only option, because
the "regular" battery (like my wife's T42, non 'p' uses) would provide
less than an hour of life, so the extended battery was the only option.=20

	I bought two of them, since I travel frequently for work and other
purposes, and I'd like to be able to use the laptop for at least one
cross-country trip without losing juice.=20

	The *MAX* life I've ever gotten out of these batteries is just over 2h,
while doing absolutely nothing. In fact, this laptop has been sitting
overnight, powered off, charging in the dock. When I came in this
morning, I booted up, and 'acpi -V' shows the following:=20

# acpi -V
   Battery 1: discharging, 97%, 02:19:58 remaining
   Thermal 1: ok, 34.0 degrees C
AC Adapter 1: off-line

	If I launch a few applications, anything that hits the disk, it'll cut
that value almost in half. Play a DVD? Forget it. I won't even get
through 1/2 of it.=20

	Right now, the laptop is running at 600Mhz, using the powersave
governor, and laptop_mode is enabled. I'm also using hdparm -B to turn
the powersave features of the drives on as well. I've done just about as
much as I can do to save and extend the battery life, except turn off
the LCD proper. The LCD dims when on battery, as it should, and dims
when idle.=20

	I've also configured X with the proper "PowerSave" and "DynamicClocks"
values, so I'm not sucking too much juice there either.=20

	Here's what shows up in /proc/acpi/battery/BAT0/

# cat info state  | sort | uniq
battery technology:      rechargeable
battery type:            LION
capacity granularity 1:  1 mWh
capacity granularity 2:  1 mWh
capacity state:          ok
charging state:          charged
design capacity:         71280 mWh
design capacity low:     200 mWh
design capacity warning: 2714 mWh
design voltage:          10800 mV
last full capacity:      54290 mWh
model number:            IBM-08K8198
OEM info:                SANYO
present rate:            0 mW
present voltage:         12238 mV
present:                 yes
remaining capacity:      52190 mWh
serial number:             103

	The curious part here, is the pretty big difference between "design
capacity" and "last full capacity" on this battery. There's a 24%
difference there.=20

	Just to be sure it wasn't a fluke, I ran BOTH of my extended batteries
down as far as they could go, by running a simple 'dd' command to drain
them (while /bin/true; do dd if=3D/dev/hda of=3D/dev/null; done;)

	The values you see above, are from an overnight recharge of one of the
batteries, after this action.=20

	The other curious thing here, is that running the extended battery down
to nothing, also drains the CMOS battery. When I completely run out of
battery life and the laptop powers off because it has no more power
left, I have to go back into the BIOS and reset the time, date, and
other settings. CMOS seems to be tied to the main battery, for some
reason.=20

	So my real question here is... are these batteries "damaged" in some
way? Or do they really run down this much in life over less than a
year's worth of usage? The second battery (my 'spare'), has just over
51000mWh in it, and its probably been used 10 times. Will IBM honor a
replacement of these batteries?

	Shouldn't a Pentium M laptop running at 600Mhz be getting WELL over 3-4
hours on these batteries? It seems unrealistic that a new battery would
give me 2 hours of life, on a laptop designed to run for multiple hours
at a time.=20

	I'd love to see the results of others in this area on similar
hardware.=20

	Thanks in advance for any advice/ideas you can provide.


--=20
David A. Desrosiers
desrod@gnu-designs.com
http://gnu-designs.com


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