Cordless Tool Battery Disassembly

[Joe Scarfo]

I need to take my DeWalt 12V batteries. Anyone here sucessfully taken apart their cordless tool batteries? Any advise to share?

Thanks
Joe in Tampa

[Carl Eyman]

I have repaired tool batteries (PC) and several radio battery packs. It is not hard. Be very careful that you note how things are put together before you take them apart. For instance, the routing of any conductors between one cell and another could be important. PC spot welds flat thin ribbons of metal to the nicad cell case. Your soldering iron will not melt this; so you will have to peel off the strip, flatten the strip, and solder it to the new cell. I peeled then off by grabbing the strip with needle nose pliers and twisting the pliers so the strip wound around the jaws of the pliers. Even if you have to buy your cells at radio shack its a lot cheaper repairing them yourself than having them repaired or buying new.

You may have to dissassemble a battery to see what size cells to buy. PC uses sub-C cells. Don't know about DeWalt.

[Steve Clardy]

Fixed on of my PC 12 volts. Year or so ago I had one that the strap came loose where it was spot welded on. I just took some sandpaper strips and shimmed it tight to the case. Worked for a year, then went dead. So I took it apart, and the loose strap had arced and burnt the bottom of the battery off spilling out the acid stuff in it. Went to radio shack and purchased a pack of two batteries, ten dollars, and soldered one of them back in place of the bad one. Works like new again.

[Bart Leetch]

I have the 9.6 Makita, how do I get them open to replace the batteries?

[Joe Scarfo]

I want to take the pack apart, not to replace the cells but to figure out a way to use my 12V battery charger to run the drill.

I don't know how to get the battery taken apart, anyone have any ideas?

Tks
Joe in Tampa.....

[Carl Eyman]

I've not done it, but I understand if they don't have screws that you can remove, the plastic is welded shut. You have to cut them open and glue them back together.

[Joe Scarfo]

Ok.... I got one apart without to much damage and the 2nd one will come apart much easier now that I know how they're assembled.

I got them apart with my smallest wood chisel and tapping it down the welded seam, this popped the seam.

I assume the dull lead is the negative and the shiny lead is the positive.

I also assume the polarity is the same as w/ any other battery? That is the tab is positive and the flat is the negative.

Anyone know if my assumptions are correct or not?

Thanks
Joe in Tampa...

[Eric Laliberte]

Joe,

I designed cordless drills for two years, and sorry but your plan won't work very well. Chargers are rated in terms of recharge time, 8 hour, 3 hour, 1 hour, 15 min, etc. Really what the manufacturer is telling you is the amount of current that is available to charge with. A 2.0 amp-hour battery will charge in 15 minutes with 8.0 amps being feed into it. With a 2.0 amp charge, it'll take an hour. Pretty straightforeward? You just won't be able to get much power out of the tool (about 24W, a decent corded tool will put out 360-480W).

Both Skil and DeWalt tried to come up with an adapter like the one you are describing. Both units delivered poor performance and never took off commercially.

If you decide to try it anyway, let me know how it works. I've been proved wrong before.

Good Luck,

Eric