I've got an older laptop (Acer Aspire 1640) that responds terribly when the battery is actually inserted. The mouse-movement is very jittery, and it seems though the entire system is sluggish too. When the battery is removed, and the laptop is operating off of the adapter, it works just fine. Does anybody know what may cause this, and whether or not I can remedy it? At the very least, if I could have the battery inserted without the laptop detecting it, that would be sufficient - without the battery the laptop doesn't sit flat, and wobbles like a bad wal-mart shopping cart.
I would be curious if your battery may be causing some form of interference with the electrical signals that are generated by the keyboard/mouse. I doubt it would be possible for you to check with a different battery.
Edit: This is including extra idea(s) and information discussed in the comments...