Which battery for supercharged drill

Hey my battery on my drill is completely dead, I can't even drill one hole, so I have decided to supercharge it. I have found a great description of how to do it, but I am not sure which batteries and charger to buy to get started. Anyone have any advice?

I think we might need a bit more information to go on, such as what kind of drill you're using, what the description you found says, ext.

I once saw an article about rigging a drill with a remote lead acid battery. That would probably be a good cheep option.

On the other end of the spectrum, the dewalt Nano-Phosphate batteries use A123 cells, which I have tested a lot myself. They are amazing cells and would last a really long time.

I have a bosch bulldog, and I am planning on building a supercharger that the batteries can fit in a fanny pack. Here is the link to the description I found:

supertopo.com/climbing/thre…;tn=0

From what I understand I need to get 12v batteries, I am not sure what amp hours to get, or which charger.

go with lead acid. if you have a 24 volt drill then two 12v 7 Amp hrs will be fine. A standard 12v trickle charger can be purchased wherever you get the batteries. if you are even remotely electronically inclined you can carge it with a LM317, a dc power supply and a few resistors. try digikey.com and they will have both batteries and a charger for sure but they probably won't have the best price.

The article looks pretty good except for one thing. They uses a plug and receptacle pair in order to allow you to disconnect the battery from the drill, but they put the plug on the battery side of the connection. Thus when you disconnect the battery, you have these two exposed metal conductors. So if those conductors happen to hit something metal, you'll get a pretty big spark.

Put the receptacle on the battery side of the connection, and you'll have a much better design.

The Amp-hour rating determines run time. If your drill draws power off of the 7 amp-hour battery at the rate of one amp, you will be able to run it for seven hours. If it only draws half an amp, it will run for 14 hours, ext.

On the charging side, don't assume that faster (higher current in amps) is better. For your 7 amp hour batteries, charging at faster then 2.1 amps (7Ah * 0.3) will result in reduced life of your batteries.

My buddy reused an old crap battery with a wire and plugs as the connector between the bosch and the new battery. It kept the drill from needing any revision, just emptied the guts of the battery and added a longer cord on both battery and drill.

Thanks everyone,

I noticed the flaw in the recepticle as well, I am glad you said to switch it. As for the batteries I have been looking around and there is a huge price difference between batteries that look exacly the same to me. Some are $10 some are $40 and the have the same rating. Any ideas? Also will the trickle charger overcharge the batteries, do I have to keep an eye on them while they are charging.

ditto on the lead-acid batteries.

try a Batteries-Plus store...

http://www.power-sonic.com/site/doc/prod/88.pdf (x 2 for 24V)