Recharging li-on batteries

[klem kedidelhopper]

I just was given two 36 volt Dewalt drill batteries that would not
take a charge. I opened them up and found what looks like the charger
unit built right into the battery pack. These batteries are about the
size of C batteries but a little bigger. They measure about 3.2 volts
apiece. I know that these are li-on cells because there are 8 monitor
wires going into the charger unit. One pack has one bad battery and
the other has several bad ones. I also have a set of these type of
batteries that came out of a laptop. The shame of it is I really can't
do anything with any of these good cells because I have no way to
recharge any of these. Does anyone know of a generic charger for li-on
cells or some way that I can recharge these? Thanks, Lenny

 

[Jeff Liebermann]

On Fri, 7 Jan 2011 20:31:59 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

Does anyone know of a generic charger for li-on
cells or some way that I can recharge these?

Model airplane and model car LIPO packs are usually just the cell,
without the electronics to keep the weight and complexity down. You
might want to Google for the chargers they use. eBay has plenty:
<http://shop.ebay.com/lipo+battery+charger>

Or, just build your own:
<http://www.eleccircuit.com/usb-powered-lithium-ion-battery-charger-by-lm3622/>

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[(PeteCresswell)]

Per klem kedidelhopper:

I just was given two 36 volt Dewalt drill batteries that would not
take a charge. I opened them up and found what looks like the charger
unit built right into the battery pack. These batteries are about the
size of C batteries but a little bigger. They measure about 3.2 volts
apiece. I know that these are li-on cells because there are 8 monitor
wires going into the charger unit. One pack has one bad battery and
the other has several bad ones. I also have a set of these type of
batteries that came out of a laptop. The shame of it is I really can't
do anything with any of these good cells because I have no way to
recharge any of these. Does anyone know of a generic charger for li-on
cells or some way that I can recharge these? Thanks, Lenny

If they are DeWalt DC9360's, what looks like a charger unit is
for cell protection. Each cell's voltage is monitored, and the
pack is shut down before it can be drained to the point where
cells are damaged. Might have more functionality to somehow
work with an external charger, but I am unaware of it.

The cells are A123's and I *think* they are a variation on the
Lithium chemistry that is not subject to bursting into flame
if/when things go wrong.

I charge mine with a DeWalt charger dedicated to DC9360
batteries. Can't recall the price, but it was quite reasonable.

For chargers that will do individual cells, look to the model
airplane suppliers.
--
PeteCresswell

 

On Fri, 7 Jan 2011 20:31:59 -0800 (PST), klem kedidelhopper
<captainvideo462009@gmail.com> wrote:

I just was given two 36 volt Dewalt drill batteries that would not
take a charge. I opened them up and found what looks like the charger
unit built right into the battery pack. These batteries are about the
size of C batteries but a little bigger. They measure about 3.2 volts
apiece. I know that these are li-on cells because there are 8 monitor
wires going into the charger unit. One pack has one bad battery and
the other has several bad ones. I also have a set of these type of
batteries that came out of a laptop. The shame of it is I really can't
do anything with any of these good cells because I have no way to
recharge any of these. Does anyone know of a generic charger for li-on
cells or some way that I can recharge these? Thanks, Lenny

You can build a single-cell charger for under $20. SparkFun has the
basic Li-Ion/LiPoly charger unit for $10 and you can power it froma
USB port on your computer or one of the plug-in USB power packs (~$5).
http://www.sparkfun.com/products/10217

John