It is very similar to the battery in an iTouch/iPod or cell phone. Over time the battery just doesn't hold as much charge as it did when new. Typically, Lithium Ion batteries are most efficient after a few charging cycles so a brand new battery is not as good as one that's been used for a week or so. One that's over a year old may be erratic (or not). On 11/11/09 4:59 PM, "Shaver Sonya" <[log in to unmask]> wrote: I have a few battery questions. There was a lot of discussion about changing batteries and I just wanted to clarify. Did people say they had better or worse performance when they purchased a new rechargeable battery? And were you talking about purchasing an actual battery pack from LEGO, not just new rechargeable AA's? Does the battery pack just sometimes wear out? Also, is it bad to "overcharge" the battery? Can we plug it in at night and leave it overnight? Some batteries can stay plugged in and they stop charging once they are full and don't harm the battery. Is that the case with this one? Thanks! Sonya Shaver in Harrisonburg ________________________________ To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html <https://listserv.jmu.edu/archives/vadcfll-l.html> and select "Join or leave the list". VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe. -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ADMIN-L. Visit https://listserv.jmu.edu/archives/vadcfll-admin-l.html to subscribe.