Rebuilding batteries

[jussi]

Anyone have any recommendations. It seems batteryrebuilders.com isn't up anymore?

(2) 18V Dewalt XRP battery

[jonmulzer]

Rebuild them yourself if you have a multimeter and a soldering iron.

[gimpy]

jussi, just got the "Fine Woodworking" magazine yesterday, April, 2008, No. 197. Page 20 has a very short comparison article titled "Rebuilt Batteries Cheaper Than New". The two places it used for replacement cells for old batteries is, 1) www.primecell.com and 2) www.voltmanbatteries.com.

Frank

[Tom Slick]

you can buy a new 18V battery for $60, it will cost you nearly that for new cells to rebuild them yourself.
sub-c cells (size battery packs use) cost between $2.50-5.00 each, an 18v battery uses 15 of them.

http://www2.northerntool.com/product/200316181.htm
http://www.amazon.com/DeWalt-DC9096-...4481487&sr=1-1

[jonmulzer]

But usually it is just one or two cells that have gone bad, dragging the rest of the pack down with them. If you can rebuild it for $5-6, that is quite a savings.

[Tom Slick]

I guess I had never thought about just replacing the bad cell, good idea. got any good ways of getting the case open? I know makita and milwaukee can be really tough if not impossible to get open without destroying them.

[jonmulzer]

Well, the ones I have messed with have all been screwed together. I know Ryobi, Craftsman and Porter-Cable are like that. Typically they use security Torx bits with the post in the middle. You can get a cheap set of bits at Harbor Freight for that. As for Makita, I don't know. I do know that sometimes screws are hidden under labels and stickers so make sure you feel around on those.

Make sure the packs are all charged up before you take it apart and then check each cell with a multimeter. If they read 1.3V or better, they are still good. Any that read under 1.1 need replaced. Most packs I have ever done have only had a cell or two that were bad. If two cells are reading 1.0V after a fresh charge, the pack will only run the tool for a few minutes at best.

[Tom Slick]

makita are glued or sonically welded together.

I'm curious how durable the newer 3000 and 4000 mAh cells are.

[jonmulzer]

You usually only see those on cheap foreign tools. Odd. Try cutting the joint gently with a utility knife. It would take a while, but then PVC cement should glue it back together.