if you are taking about the dome top battery.
a batterys+ store can fix them.
after seeing how they used a heat gun to take the top off and
resolder the dome onto a new battery i did it myself the second time
for $20 bucks. i think i got it off amazon, that was like over 3 years ago.
dont know what the price would be now.
still on amazon for 23 bucks.
note my dome top is gorilla taped on, this is the 3rd battery
on this top and the adhesive glue was not as sticky as the 2nd time.
****
sorry, i just realized the 4500 used lithium ion.
still might be able to have it rebuilt.