battery and AC Adapter together

[deelo83]

Hello, I have been told two different stories about using the battery and AC Adapter at the same time.

1. When the using the AC Adapter, you should take off the battery.

2. It doesn't matter if they are both on the computer.

So, which one is true?

[AlphaKilo470]

Assuming you have a newer ThinkPad, since lithium-ion batteries all have integrated charge control hardwere in them, you really don't have to worry about damaging the battery while leaving it in with the AC adapter plugged in.

Assuming you have an older ThinkPad, this may be untrue. For some older ThinkPads that either have NiMH or NiCD batteries or some lower end ThinkPads that have LiION batteries but lack IBM's advanced power features will charge the battery when plugged in regardless of whether the battery is full or not, so you would want to remove the battery before charging in order to save battery cycles.