Do rechargable batteries lose the ability to hold a charge if the're kept in the charger?

Question

like for a laptop or that wii charger thing

Answer 1

It will generally not hurt Laptop batteries because Lithium Ion (or polymer) batteries aren't harmed by it, but the Wii charger battery is a different story.  Depending on what kind of battery it is using it can damage it, and cause it to not hold as much of a charge the next time.  If you look at the battery pack it should say what kind it is, and then just google it or go on wikipedia, and you should be able to find out if there is any risk to leaving it on the charger.