Last night I attempted to charge the battery on my Dell laptop. It has been about 3-4 months since I charged it or even used it. Anyway, I plug in the charger, the green light on the charger lights up which tells me it's working, but as soon as I plug the charger into the laptop the little green light slowly dims to nothing. The lights on the laptop never come on to indicate it's charging. The battery is a lithium ion. Can these things just go bad and not take a charge any longer? Are there any good on-line sources for replacement batteries? I checked Dell.com and they want $129 for a new battery.