This circuit came about as the result of an urgent need for a NiMH battery charger. No suitable dedicated IC being immediately to hand, the author pressed an L200 regulator and a 4.7 kΩ NTC thermistor into service. Those components were enough to form the basis of a charger...
Universal Constant Current Charger for Lead Acid Battery
Posted by Okla
Posted on 06:21
Charge TerminationOnce a battery is fully charged, the charging current has to be dissipated somehow. The result is the generation of heat and gasses both of which are bad for batteries. The essence of good charging is to be able to detect when the reconstitution of the active chemicals is complete...
Simple Lead Acid Battery Charger 1
Posted by Okla
Posted on 01:04

Except for use as a normal Battery Charger, this circuit is perfect to constant-charge a 12-Volt Lead-Acid Battery, like the one in your flight box, and keep it in optimum charged condition. This circuit is not recommended for GEL-TYPE batteries since it draws to much current. The above circuit...