I have a Black & Decker Firestorm 14.4V drill & also a reciprocating saw and search light. The drill came with a battery and so did the saw/light and I also bought a spare. So I have 2 chargers & 3 batteries to go with the 3 tools. The drill & saw & light all work well and I'm too poor to replace them, so I want to see what I can do with what I have.
The batteries are 12 cell Sub-C NiCd
One of the batteries has been rebuilt (12 new cells) a couple of years back and is working well.
One of the batteries is original and reads 6.3V after charging - I've pulled this apart and 5 cells read over 1.2V and 7 cells read 0.00V.
The 3rd battery is also original and reads 9.4V after charging - I haven't pulled this one apart yet.
So - what to do? The rebuilt pack cost heaps to have rebuilt - around a hundred bucks! Stuff that - I'm not going to pay that for my other 2!
What I'm thinking:
Why don't I buy a hobby LiPo pack that will fit inside the battery housing and make that sucker work? A 4S LiPo pack with balance taps that should fit OK would cost around $16 + shipping from Hong Kong. 1600mAh is probably higher than my original sub-C NiCd cells and 30C constant/40C peak is probably enough output to run the drill or saw just fine.
So, has anyone tried this? Any reason why this wouldn't work?
Edit: For anyone wanting to do this it is important to realise that the hobby LiPo packs are unprotected LiCo batteries and there is some risk of a 'vent with flame' situation. There is no protection from the cells being discharged below the minimum recommended voltage, so adding a Low Battery Alarm to the pack would be a really good idea. Charging on a non-flammable surface would also be a sensible thing.