Hi Ohio,
I have the same problem with my Whites XLT rechargable pack, seems to last about 30 mins tops.....
Well, I opened it up and it's shot, corrosion mostly and batteries look bad. I just ordered a soldering gun and I'm going to give it a go. I believe I can clean it up and make my own pack of re-chargable batteries to fit and work. I'll take pics and post later.
Ned