[ltp] Battery does not charge at all T400

Paul Seelig linux-thinkpad@linux-thinkpad.org
Sun, 13 Mar 2016 14:28:02 +0100


On 03/13/2016 07:28 AM, Toyam Cox wrote:
> battery cycle count (as reported through the tp_smapi module) is 331
> cycles. So the battery is in reasonable condition, and the thinkpad
> itself is in good condition in all but caring the battery.
> 
I wouldn't call 331 cycles a death verdict yet, but it certainly is no
indicator for a battery being still in reasonable condition either.

I have had SANYO batteries with much less cycles die, while a Panasonic
produced in 2006-08-07 is still providing slightly half of its former
capacity of 84240 in spite of its 814 charge cycles. But only Panasonic
are known to have such an incredible longevity (with SONY being worst).

> I do not know why, but despite buing plugged in, while the computer is
> on or off, the battry stays at 0$ charge. I cat
> /sys/devices/platform/smapi/BAT0/state and get "idle" back .
> 
Does another battery charge fine on the same machine?

Try with another Thinkpad of the same generation or also a widescreen
14.1" T61, in order to exclude your T400 from being the main culprit.

> Yes, the battery is at 0%. I can unplug the laptop and watch the machine
> instantly poweroff.
> 
When was the last time you ever used that battery? How many months did
it sit unused before? Chances are it has simply died while being deep
discharged during a too long period of not being used?

I once acquired a nice 14.1" T60 in excellent condition for just a
steal. The former owner forgot its power on password and just had it
lying around unused for some unknown amount of years before he decided
to give it away. When i finally received it, the Panasonic battery had
just a dozen charge cycles, but was dead as a brick. I tried charging it
continuously and uninterruptedly over a full week on a well known good
machine, hoping to miracuously resuscitate it, but to no avail.

Extended storage of laptop batteries without periodic charge control and
refresh simply kills them. Batteries in general are consumables that
eventually die after a more or less extended time of usage and simply
need to be replaced if it happens.

Hope you are still lucky, though.

Regards,
Paul