Estley,
I've done exactly what you a contemplating doing. Rebuilding a DeWalt 14.4 volt battery pack. Before I lay out the facts I'll give you the final answer so you can quit reading and move on:
It's not worth it.
Here are the facts for DeWalt 14.4 v drill battery packs:
- the battery packs are based on nicad battery technology.
- the packs are built up from series connected sub-c cells
- nicad batteries are 1.2 volts per cell as opposed to the typical 1.5 volts per cell for alkaline
- to get to 14.4 volts you need 12 cells (12Ă—1.2 = 14.4)
- you notice pretty much all of the nicad battery pack voltages are some multiple of 1.2, like 7.2 (6Ă—1.2) 9.6 (8Ă—1.2) 12 (10Ă—1.2) 14.4 (12Ă—1.2) 18 (15Ă—1.2) and so on. That's because they're all built up from a series of 1.2 volt nicad cells
- nicad sub-c cells are around $2.50 - $5.00 USD
Sanyo Nicads
Powerstream Nicads
- you need 12 of them per battery pack so you are looking at $30 - $60 in raw nicad batteries per pack
- when you open up the battery pack you will notice the factory cells are resistance welded together (a good thing).
- you will also notice the factory packs the batteries in with near zero wasted space.
You probably dont have a resistance welder that will work to spot weld the tabs of one battery to the post of the other battery. Too bad, that means you are going to have to solder the tabs together and possibly have to use some jumper wire. This is bad because the connections are not as good and the soldered connections take up more physical space. You have a poorer solution that you have a hard time fitting back in the case.
But if you decide to keep going make sure you buy the batteries
with tabs, you'll need the tabs, top and bottom, to solder together.
If you are determined you can make it work. It is possible to get the batteries soldered together in way that is reasonably sound and will eventually fit, with a little filing and pounding.
Hopefully you made sure the batteries bought are suitable to use with your factory dewalt charger with similar charging characteristics. That way you can just drop you newly rebuilt pack onto the factory charger, otherwise you'll need to find or build a new charger.
Oh, and don't forget, when you cracked the case you might have split the plastic, but even if you didn't you'll have to find a way to epoxy it all back together and not leave any bumps or changes in shape so it will still fit and lock into the tools handle.
And finally nicad batteries require controlled disposal, dont just throw the old ones in the garbage.
So, if you went through all that fun you can actually rebuild a tool battery pack. And it will work, and it will have performance similar to a factory pack. But unless you've got a secret stash of sub-c cells, the right tools, patience and general handy skills, you wont save much, or any, money, and you'll likely end up with a sub par result.
So I'll say again:
It's not worth it.