X61s cuts out

[cfds]

Hello,

Since a while my X61s shuts down from time to time like if you suddenly remove the power supply. So far it seems only to happen on battery power and it does it random...
I am running since a couple of months on a new non OEM 8cel battery. I find it difficult to believe that this battery would cause this problem...
The event logs show; Kernel power ID 41...

Suggestions? Could it be a problem on the motherboard? I hope not because this X61s is in perfect condition and runs perfect. Should I look for a replacement X61s to have a spare in case of?

Thanks

[RealBlackStuff]

If you run without battery, you also have those problems?
If not, the battery is your problem.
Any non-IBM or non-Lenovo battery is usually suspect.

[cfds]

Never tried running the X61 without battery, but it has never happend while recharging the computer...