seeking help/advice on 14.4 V Charger

[**DONOTDELETE**]

Hi Guys,

I recently bought 2 x Hitachi 14.4V NiCd Battery packs for their cordless handtools.
I plan to use these packs for powering 12V biking lights. I would like to build a simple, inexpensive charger for these packs. Can anyone point me to a design, or offer some advice? I have basic electronics skills and tools and better than average DIY skills.

For now, I don't mind even a simple circuit in which a simple intermatic wall timer will shut off the circuit. the only requirement that I have is, it needs to charge the whole pack, without removing the batteries. I have the standard 12V Makita charger but I doubt that it has enough voltage to properly charge a 14.4V pack. but if there's a way to leverage a design off of that, it would be great.

I opened the battery pack and there are two devices attached to the batteries. I suspect one is a thermistor and but I'm not sure what the other is. one is a small, 2 wire device about the size of a small tantalum capacitor. the other is a long, flat, black, 2 wire device about the size of a BIC pen cap.

thanks for any help!

Jeff

 

[Klaus]

zaki,

do a search on 12 cells charger - I wrote something about that in one of my 1000+ lumens threads - basically you need a 18V PS supply and a watch ;-)

Sorry for short post - need to run

Klaus

 

[MrAl]

Hi there,

Check this out:
http://forum.howstuffworks.com/showthreaded.php?Cat=&Board=elec&Number=37408

It's your most basic NiCd charger
with a schematic. You'll need an 18vac
output from the transformer rather then
the 6vac shown for charging only two cells.
You can also use a 18vac wall wart with
the diodes, or a 18vdc wall wart.
If you have ten batteries in series,
you can use a 30 ohm, 2 watt resistor
in series with an 18vdc wall wart.
Check the current to make sure it's not
too high.

Have fun,
Al