T400 automatically shut off with battery pluged in

[wenh]

I have been experiencing problems with my T400 battery these days.

I usually run my T400 with both AC adapter and battery pluged in.  From time to time, my system automatically shuts off without any warning when I was running some programmes.  And when this happens, I am unable to turn on my laptop, unless I unplug both battery and AC adapter and re-plug in either of them once again.  I don't know exactly why this happen.

I looked it up in the board and didn't see any similar thread on this issue.

Anyone gets any idea?

Great Thanks

[ColonelONeill]

Could it be an overheating issue? Does your system lose time when it is turned off with no power source attached?

[wenh]

Thanks a lot for replying.

It might be due to overheating as that basically happened when I was running some programmes(sometimes close to 100% use of CPU, mine is dual-core).  But realizing that I was doing the same thing a couple of monthes ago and nothing bad came up, I doubt overheating is the main reason.

Also, it only happens when I am using external electrical source while with the battery pluged in.  So I guess there must be something wrong with the battery.

[wenh]

I didn't notice any system time loss because each time I rebooted the system immediately after crushing.

[ColonelONeill]

Install HWMonitor and watch the temperatures. However, the critical shutoff temperature is 105 degrees Celsius, so there should be noticeable amounts of thermal energy emanating from the laptop.

So if you run the laptop on AC only, the shutdowns don't occur?