# [EVDL] How to use DeWalt A123 battery packs...



## EVDL List (Jul 27, 2007)

Stupid Yahoo... ate my first email I typed up. Been asking me for my password a lot today... Anyway, let's see if I can remember what I typed.

The latest issue of Electronic Design has a "Design Idea" named "Nanophosphate Batteries Create High-Energy, Rechargeable Source". They prototyped an electric bicycle by reverse engineering a DeWalt DC900 drill and DC9360 battery back. They used (4) unmodified battery packs and a stock DC9000 charger, using connectors from (4) 509 flashlights. They used this to power a Crystalyte 406/409 brushless bycycle motor with a 72V 20A PWM controller built into a 16" bicycle wheel. They have put on about 700 miles on the bike, sustained speeds of 25 mph, and 11 mile range.

Interesting note: it appears that the drill doesn't contain the power electronics for controlling the motor speed; the battery does!

http://electronicdesign.com/Articles/ArticleID/19322/19322.html

- Steven Ciciora




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## EVDL List (Jul 27, 2007)

> Interesting note: it appears that the drill doesn't contain the power
> electronics for controlling the motor speed; the battery does!
>
> http://electronicdesign.com/Articles/ArticleID/19322/19322.html
>

I didn't catch that at first, interesting indeed.

I can understand not using the built in PWM since they are running the
batteries in series/parallel, but I wonder why they used a resistor
network instead of just shorting pin 6 to 7? From what I'm reading that
should have given them 100% duty cycle output.

I'm sure they had a reason, I just wonder what it was.

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## EVDL List (Jul 27, 2007)

My son set up a bike like that last winter, inspired a bit by a friend's trike. Here's a bit of info on the trike: http://www.geopathfinder.com/9659.html
So far they work fine.

Jim, in western Wisconsin


> Stupid Yahoo... ate my first email I typed up. Been asking
> me for my password a lot today... Anyway, let's see if
> I can remember what I typed.
> 
> The latest issue of Electronic Design has a "Design
> Idea" named "Nanophosphate Batteries Create
> High-Energy, Rechargeable Source". They prototyped an
> electric bicycle by reverse engineering a DeWalt DC900 drill
> and DC9360 battery back. They used (4) unmodified battery
> packs and a stock DC9000 charger, using connectors from (4)
> 509 flashlights. They used this to power a Crystalyte
> 406/409 brushless bycycle motor with a 72V 20A PWM
> controller built into a 16" bicycle wheel. They have
> put on about 700 miles on the bike, sustained speeds of 25
> mph, and 11 mile range.





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## EVDL List (Jul 27, 2007)

Quite interesting stuff you got there.

Just a note... you may have realized by now that there's no reason to retire
your ET for the winter just because it's cold. Mine sees more use in the
winter than it does in the summer. Sure it has less range, but still enough
to blow both mine and my neighbors driveways twice a day.

Stay Charged!
Hump






> jiminwis wrote:
> >
> > My son set up a bike like that last winter, inspired a bit by a friend's
> > trike. Here's a bit of info on the trike:
> ...


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