T61 Battery Problem

[rebop]

Hi folks,

I have two Thinkpads - a T-43 and a T61. The battery in the T43 works as expected and maintains close to rated capacity. But in the T-61, a new battery rarely shows full capacity and on each maintenance cycle, as I have read that it takes several to rise to rated capacity, I LOSE more and more battery.

I can tell you the cells in the T43 are Panasonic and the cells in the T61 both Lenovo battery and a third party I thought I would try are Sanyo's. Not ruling out that is the problem.

There are no BIOS updates that indicate anything that would cure a charging or battery problem.

Ran a test last night and I am more confused than ever. Here are full details:

New third party battery with 51.86 capacity. Showed 47 something first time, so following suggestions it may need to be maintained a few times to reach rated capacity, I did. Each time it lost what it thought was full charge (not design capacity - current full charge level) until down to 45.21.

So, I thought maybe it was my power scheme and alert settings. I thought I stumbled on to something.

So, I turned it to Always On, no alerts and tried again.

It started at 95% charge and got to 42.87 saying 10 minutes left to 100%. Then 13 minutes, then 21, then 30 something. It never got higher than 42.87 before it started to discharge.

Now, after full discharge and recharge I sit at 43.42! New battery, 5 cycles, all in maintaining.

Is this the battery cells, the chip or the charging circuit in the Thinkpad?

I'd really appreciate some input as I have two batteries that should be like new with 80% or less of what they should be holding for a charge.

Thanks for any input.

~Bob