porter-cable

I have a large collection of 18V Porter Cable tools. The oldest are from 2010, and the batteries are starting to fail. I've heard that Harbor Freight's 18V battery uses the same cells. A new Porter Cable battery is about $40, whereas the Harbor Freight battery, with the ubiquitous 20% off coupon, is just $10.40.

Both batteries open by just removing a few screws. The Porter Cable battery is better packaged, but the layout of the cells is identical:

side_by_side.jpg