I've had my Inpsiron 1501 for about a year and a half to 2 years. I needed to replace my original battery as every time the computer would boot up I would be given a message to insert a Dell battery or it would not charge. It did however work fine for a few months after the message started appearing. When the battery started acting up finally (i.e. not charging anytime) I bought a new one. It was a model GD761 that I purchased online from another non-Dell retailer. When I put in the battery while I was connected to my A/C adapter the battery indicator light would flash green. A day later I checked up on it and it simply stays a solid green. When I turned the computer on today it only had a 40% charge on it although I'd kept it plugged in for several days unused. The battery display icon on my desktop also says that the a/c adapter isn't plugged in. Looking at some other cases on this forum for different models, a new motherboard my be in order, but that's a thing I'd rather not do. Hopefully it's because I purchased a charger for my old battery and now the same charger cannot be used for my new one, but there may be something else. My service tag is: 4MQ3BF1 if that is of any help.