I’ve got a dead 14.4V Dewalt DW9091 pack. It has a series string of sub-C size Nicads.
It isn’t worth buying a new 14.4V Dewalt battery. If I can find one, they go for about £90. DeWalt doesn’t even sell 14.4V tools anymore.
I’m thinking about rebuilding it with NiMH cells or maybe even LiIon.
4 x 18650s would fit and have more capacity than the original pack. 26650s might fit. LiIon is going to over-volt the tool. The drill is over 10 years old and a little hot rodding will be good for it. :smiling_imp:
My charger is newer than the drill and can handle both NiCd and NiMH. Supposed to work with DeWalt packs between 7.2V and 18V. It might blow up a LiIon series string. Or not???
Any ideas or suggestions? I’m open to crazy ideas. The drill and battery pack are going to recycling if I can’t hack it back to life.
you can use 4s li-ion battery, you will also need BMS pcb, a different charger too
a little over voltage wont do any harm, but if you want to play safe, maybe use 3s li-ion battery
I would say throw it away and buy a new drill (lipo) and when those batteries die it is much easier to replace them. Converting to lipo isn’t as simple as it sounds and those cheap BMS pcb’s aren’t what they claim to be. Look it up on You tube, there are numerous tests and reviews.
Only conversion I would consider is to stuff a lipo battery or batteries inside and charge them separately with some kind of a balance charger.
I’ve got a Dewalt drill that uses the same battery, and have about decided it’s cheaper to just buy a new drill. The drill works fine, so as a last attempt to save it, I just ordered a third party replacement battery for much less money than the Dewalt and will see how long it lasts. When it goes bad (may be total junk) I’ll shop for a new drill. This may be sooner than later, as I’ve not had great luck with these third party replacement batteries, but I just hate to toss a perfectly good drill.
Was gonna suggest just that. For putzing around the car and such, a lighter-plug and some heavy gauge wire would be perfect.
Or, use the same wired approach, but with a separate battery-pack and, say, a 6’ cord. This way, you just drop ’em into a Tomo and keep them around for other things, too.
Nb: without the battery-pack acting as a counterweight, the drill may feel kinda top-heavy. Not a big deal, but takes a little getting used to. But, it’ll be significantly lighter, too.
Hell, with beefy alligator clips, you can just attach it to a car-battery.
Used their 4200mAh cell to overhaul a DeWalt De9502 battery pack a good deal of months ago. Vastly superior battery life and increased torque versus a stock pack.
If you have a garage or dedicated workspace that could benefit from a handy drill:
strip the batteries and attach a long cord to the + and - terminals, (old vacuum cleaner cords are great!) and hook it up to the power supply from an old computer.
May not get maximum torque or RPMs but most times you don’t need to drive lag bolts.
Methods for converting old PC power supplies vary, google for your model.
