T60 Battery discharges even when plugged in

[nutrocobra]

Hi all,

I'm having a strange issue with a T60 battery. The user reported that the battery was slowly discharging over the course of the day while the laptop was plugged in. Switching to a known good battery and AC adapter did not solve the issue. During testing I noticed some strange behavior, in that the battery will continue to charge even after it has charged to 100%. It will then very slowly begin discharging. I left the laptop on and plugged in overnight at 98% and when I came back this morning the battery was at 50%. But once I unplug the AC adapter and wait for the battery status to go from "charging" to "discharging", then plug it back in the battery meter goes back to 100% after about ten seconds. Then the whole process repeats itself. I replaced the system board but that didn't solve the issue either. I've run out of things to try, hoping someone here might be able to shed some light on this.

Thanks in advance!

[DAH]

Have you tested the wiring between the battery connector and the system board? I'm assuming there is wiring between the two, if not it looks like you might have another bad system board. Looking at the maintenance manual it suggest that the backup battery should be tested as well.

[RonS]

Using a 65W power supply on a 'p' model?

[ryengineer]

Which Power Manager are you using?

[nutrocobra]

Using a 65W power supply on a 'p' model?

We're using a 90W, regular T60.

It appears the "known good" battery wasn't as good as we thought it was. Left off overnight and not plugged in the battery managed to drain itself completely, and now it won't charge at all. Laptop boots up just fine when plugged into AC. Waiting for a replacement battery to see what happens next.

Thanks to everyone that replied!