Ditto, on the Radio Shack answer.
I been playing wif RC cars for better than 20 years and have also tried to pump up some older cells. They may look good on a discharger but when actually trying them in a car/buggy/truck..., They will flop!
I have even bot some new ones on Ebay that charge up just fine but they will never be used in one of My vehicles, cuz they just simply SUK!
Even for just bashing, it wood be best to just git new ones. They ain't that expensive and U'll waste more time and energy trying to pump-up those older Packs.