# drill batteries?



## DavidDymaxion (Dec 1, 2008)

That's exactly what the Killacycle, BYU, and other racers are doing. A123 batteries out of DeWalt tool packs seem to be the favorite.


OMT said:


> i have an idea for a performance ev in the next year or two when im done my first conversion...
> 
> what about using 18v power tool lithium ion batteries? their tough, pretty light, have a decent amount of power? if i could get them cheap, by bulk, does anyone see a problem with putting a few hundred of them( or more) in en ev. i guess charging might be an issue?


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## mhud (Oct 19, 2009)

If you can get them for a great price, it might be worth it. The biggest problems I see are:

Less-safe chemistry than LiFePo4
Lots of individual connections
Strange Shape -- hard to get a lot of them in a small space. 

If you are willing to work around those issues, you might have a cheap traction pack on your hands. 

It'd be interesting to open up one of those drill batteries and see if there are just a few standard-size lithium cells in there, such as 18650 form-factor cells in series.


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## mhud (Oct 19, 2009)

Here's a link with a guide for dissecting one of those DeWalt packs containing A123 cells: http://www.slkelectronics.com/DeWalt/packs.htm

Cool! Thanks for the info, David.


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## pgt400 (Jul 12, 2008)

mhud said:


> Here's a link with a guide for dissecting one of those DeWalt packs containing A123 cells: http://www.slkelectronics.com/DeWalt/packs.htm
> 
> Cool! Thanks for the info, David.


A123 batteries are Lifepo4....they are rated at 30C. The best there is in Lifepo4 batts.


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## Duxuk (Jul 11, 2009)

In England the 36V 2.2Ah DeWalt packs cost at least £182 each. £10K wouldn't give me much more range than my £600 LA pack! Yes, I know they have many advantages but until the price comes down, I don't see them being viable. What sort of price do they come in at in the USA?

Andrew.


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## pgt400 (Jul 12, 2008)

A123's are about $6 per cell. I built a 16S4P pack for an E-Bike...fantastic performance but yes a little pricey. I've bought used cells for $4 each on ebay. Won't want to build a large pack with them though!


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## mhud (Oct 19, 2009)

Duxuk said:


> In England the 36V 2.2Ah DeWalt packs cost at least £182 each. £10K wouldn't give me much more range than my £600 LA pack! Yes, I know they have many advantages but until the price comes down, I don't see them being viable. What sort of price do they come in at in the USA?
> 
> Andrew.


http://www.dewalt.com/tools/cordless-batteries-dc9360.aspx

These packs are going for between $170 and $200 USD. Sounds like you're paying double overseas -- Ouch!

Edit: Here's a guy that's used these specific packs to get a bunch of A123 cells: http://ev.whitecape.org/insight/A123/


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## Duxuk (Jul 11, 2009)

Yes the price range is the same in the UK-180 to 200. It's just that it's £ not $ so we do pay more. By the time I had imported them from the USA though there would be little difference in cost to me. Looks like I'll have to move to the US if I want to use A123s.

I here your cheese is the worst in the world though so I think I'll stick with the lead acid for now.

Andrew.


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## Duxuk (Jul 11, 2009)

I've just recalled that I got up at 5.30 am today with the pathetic excuse that I needed to go to a 24 hour supermarket. It was 3.9 miles each way so I didn't "spare the horses". Great drive. Lots of twists and turns on the American sounding "Myles Standish Way". Since I toed the front wheels in the handling has been tranformed. I recharged in about an hour. Used about 140Wh/mile. Thats about 10 pence (15 cents) worth of electricity. You probably get that cheaper in America too!

Tommorow I have no need at all to go to the supermarket-so I'm going to talk to my wife about cheese and see if she suggests we need some.


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## mhud (Oct 19, 2009)

It's hard to believe you'd be paying 80% overhead by importing from the US, but you will know that better than I will. 



Duxuk said:


> Used about 140Wh/mile. Thats about 10 pence (15 cents) worth of electricity. You probably get that cheaper in America too!.


It sounds like you burned through 1.09 KWh. Here in Sacramento that would cost you just under $0.10 USD which is £0.06 at today's exchange rate. That is, if you could losslessly transmit the power from here to there...

Note that just because it's called "American cheese" does not mean that's the only cheese we have over here.


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