self-made charger for cordless drill batteries

[jtnospam]

I came across a lot of cordless drills and other such appliances at an estate sale, but it had been already picked over for parts, and someone else had bought up all the battery chargers. I don't know a whole lot about these things, but neither am I an ignoramus, and I was wondering if someone out there knew of a website or could just tell me how to rig up some homemade chargers with these small plugin transformers and some alligator clips. I know about polarity and voltage, but there is no indicator on these batteries on which is positive or negative, and most of them have three or more contacts. The replacement chargers cost an arm and a leg, and eBay hasn't had what I need for several weeks now. Thanks in advance for all useful replies.

[Main Man]

Best to find a proper charger, otherwise you may cook batteries if you make device that simply inputs DC voltage. Look on E Bay for makes you want; are often there.

[m Ransley]

There is alot to charging batteries, just a few examples, 1.2V Nicads are charged at 1.35 , dead at 1.2 but 1.5V is good to charge at. When it gets warm or it has voltage drop its fully charged. RC Hobby stores and magazines offer what you want , RCers know more about batteries because they race in classes that limit cells and must get the most life and power out of the cells, plus they pay big premiums for matched cells, go to a hobby shop, get RC Car magazine or online at Tower Hobbys etc. but your batteries may be junk, you wont know till you use them. now Nimh, L ion is a new game of charging rules to learn.