And for Mango-Man, I'd estimate the repaired batteries last 85% as long as when they were new. I figure I can do the same repair again in a year or so and still be at less than half the cost of one new 12v battery. Before putting the whole mess back together, I moved a few cells from one pack to the other to balance out the potentially weak cells. I should add that 4 cells were bad in one pack and 2 in the other. I could have spent about double that for better batteries, but got the cheaper ones so the amp/hours per cell matched the ones from the packs. I bought the 6 cells I needed at Radio Shack for $9 or so. Of the 20 total cells, only 14 were any good (and several of those were marginal). On my DeWalt 12V batteries that were repaired, each actually had 10 1.2v cells. It's been over a year since the repair, the charger still works and the same tape is still holding it together. When I had to cut open the charger for the DeWalt to replace a blown fuse, I just wrapped it back up with black electrical tape. I suppose, if necessary you could glue it back together. Sealing? I was able to open the packs by simply removing 4 screws. Essentially I was only working with 4.5v of power. For my 12v Dewalts (9 - 1.5v cells) having 3 bad cells each, it meant that I wasn't even getting the benefit of the remaining 6 good cells, because they were giving up their charge to the the three bad cells with reversed polarity. If a battery pack is allowed to go very dead, the cells holding a higher charge will actually start recharging the weakest cells and reverse the polarity of those cells. who likes fixing things, it wasnt so bad. I just ressurected a pair of 12v DeWalt batteries ($56 each new) for $9 in rechargable batteries and an afternoon of fussy work. Again, you will have to solder the leads back on.
Be certain, when putting new cells back in, that the polarity is correct. You will probably have to cut or de-solder the leads going from cell to cell to beable to extract the bad cells. Mark the cell and keep checking the cells until you get to the end. From cell to cell you should see a 1.5v jump. Using a multimeter, check and make note of the voltage reading between that point and the negative end of that cell and then from the negative end of each cell in sequence. After your battery pack has been on the charger long enough, take the cover off the pack and identify the positive end of the first cell in the chain. These are available at Radioshack or any place that sells rechargable batteries. An 18 volt battery pack is made up with 12 "C" sized rechargable cells.
It will take some doing, but you can repair cordless drill batteries.
0 kommentar(er)
