NiCad Batteries, hassle and solution

[reb]

I got tired of buying replacement batteries for my 12v DeWalt drill. Even aftermarket batteries were a bit expensive for my occasional use. I dismantled an old battery and attached a 12 ga cable to it. Now I hook it to a 12v lead-acid battery when I need it. It is not as convenient as before, but it does the job.

 

[kc5dlo]

I learned recently the 18 volt Black and Decker batteries can be "rebuilt" by swapping in the guts to a 18volt Harbour Freight Battery. Simple and cheap.

 

[Larry Caldwell]

NiCd batteries have a flat discharge curve and high current potential. You can get an amp at 1.2v out of a NiCd AA cell until it is discharged. They are great for high torque, short duration use. They need to be frequently discharged to avoid the memory effect, though newer batteries are better than the old ones were. They also need a smart charger to avoid getting fried if you leave them on the charger. They do not have a good shelf life, but store them discharged rather than letting them leak down. Some manufacturers recommend completely discharging them and then shorting the terminals.

 

[crazyal]

One thing I'm finding out with Li batteries is they have lots of electronics in them. My Milwaukee batteries will just shut off when the circuit says they are low on power. I've had issues charging them because the circuit will decide that the battery is not ready to be charged. They also store the information so you can't charge them until you erase the memory. That means, if it has a charge left, you use the battery some more. If not then you leave it on the charger and unplug it from the wall. Once the charger lights go out then the memory is erased. It's nice having a charge gauge on them but I have to wonder how well will they work years down the road.

 

[crazyal]

I have a Makita 2sp 14.4 Volt. I replaced one of the orig packs with high capacity NiMH -- poor comparative torque. I returned the pack and got another. Same thing. I had the pack rebuilt with NiCad at Batteries Plus. Great torque -- real zip. NiMH has higher internal resistance than NiCad and thus cant deliver the high currents that NiCads can. Your extra speed overcame this but unfortunately the smaller parts are fragile.

I sure wish Lithium retrofits were available. But these packs can be dangerous unless treated in a controlled fashion. Electronics in drill, battery, and charger. :confused3:

I've never had much luck with Makita NiCad batteries. Back in the day they were great but it seams like they aren't as good. The 18v NiMH worked fine and neither battery had died. Clearly they had enough power to strip out the gears in the gearbox. Not sure if that means they were strong or if Makita just made a cheap gearbox. Either way I chucked the whole mess in the recycling bin and switched brands.

 

[dfkrug]

I learned recently the 18 volt Black and Decker batteries can be
"rebuilt" by swapping in the guts to a 18volt Harbour Freight Battery. Simple and cheap.

I have done that too, since I bought a B&D pole chainsaw a while ago. I also buy the HF 18V
battery packs, take out the cells, then use them in other brands. They go on sale for as
little as $10 each. My earlier Chinese 18V cordless drills actually had Energizer brand NiCad cells
in them. (Did you ever notice that the cheaper of the Chinese battery packs have no thermal
protection inside?)

I did that with my Makitas, but they are quite difficult to dissassemble. The newer ones have to be
cut apart. Oh, and they use TWO thermisters, not one. Still love those Makitas, but after years of
hard use, my oldest, a 9.6V impact driver, died with broken gears.

 

[SPYDERLK]

I have a Makita 2sp 14.4 Volt. I replaced one of the orig packs with high capacity NiMH -- poor comparative torque. I returned the pack and got another. Same thing. I had the pack rebuilt with NiCad at Batteries Plus. Great torque -- real zip. NiMH has higher internal resistance than NiCad and thus cant deliver the high currents that NiCads can. Your extra speed overcame this but unfortunately the smaller parts are fragile.

I sure wish Lithium retrofits were available. But these packs can be dangerous unless treated in a controlled fashion. Electronics in drill, battery, and charger. :confused3:

I've never had much luck with Makita NiCad batteries. Back in the day they were great but it seams like they aren't as good. The 18v NiMH worked fine and neither battery had died. Clearly they had enough power to strip out the gears in the gearbox. Not sure if that means they were strong or if Makita just made a cheap gearbox. Either way I chucked the whole mess in the recycling bin and switched brands.

Ah. Further contributing issues. 18V vs 14.4 lowers the amperage requirement for power. With a higher voltage you essentially ease away from the applications requiring hi current where NiCads excel.
larry