This circuit is intended for charging lead-acid batteries with a solar panel. The customary diode that prevents the battery from discharging through the solar panel has been replaced by a FET-comparator combination. The charger will stop charging once a pre-set voltage (temperature compensated) has been reached, and recommence charging when the voltage has dropped off sufficiently. The load is disconnected when the baterry voltage drops below 11V and reconnected when it gets back to 12.5V.
The circuit has the following features:
* Charges until Vbat = 13,8V (adjustable), then float charges;
* Shuts down load when Vbat < 11V (adjustable), resets at 12,5V;
* Temperature compensation;
* Will work with cheap and readily