LAPtop Dual Battery Issue

[Mikkel L. Ellertson]

chris at idlelion.net wrote:
> I have a ThinkPad T60 (Core Duo) running FC6 with latest updates. I
> recently swapped out the DVD drive for a second battery.
> 
> Now when the second battery reaches some very low threshold (not sure if
> it's 0% or 5%), the machine SHUTS DOWN. There's no warning; it doesn't
> suspend; it doesn't hibernate. At least it doesn't just turn off. Really
> very annoying.
> 
> After I turn it back on, it operates just fine with that second battery
> at 0%.
> 
> How can I fix this or at least learn what's going on?
> 
> Thanks,
> Chris
> 
I am not sure how to fix it, but what I suspect is happening is that
when the second battery is almost dead, it is generating an ACPI
event. You can check this by looking in /var/log/acpid. If that is
the case, then HAL is probably processing the event, and is not
smart enough to know that even though battery 1 is reporting a power
 low alarm, that battery 0 is still doing fine. The system is
probably motoring battery 0 only for power level, and because it
still has plenty of charge, you do not get a low power warning.

It is also possible that the machine BIOS is not handling having 2
batteries properly, and is doing a shutdown when the second battery
goes dead. You may want to check to see if there is a BIOS update
for the machine.

In ether case, the logs should give you a clue as to what is going
on. If it is Linux doing the shutdown, it should show in the logs.
If it is the BIOS, then the log will not show any shutdown messages,
but you should see some messages indicating that the machine did not
do a proper shutdown.

Mikkel
-- 

  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!