I had the same problem with a Nextel 7510. Any battery I put in it would either die immediately or within 20 minutes. It did this for two regular batteries (one of which was brand new) and an extended battery that I borrowed. All three batteries held an all day charge when used in a Cingular 7290 or a Nextel 7520.
I ended up swapping the 7510 for a 7520, since it was work provided (then later a cingular 8700c a month later).
Good luck. Maybe try the solution woody suggested?
Last edited by Aroc : 09-20-2006 at 09:46 PM.