This is a great a simple Solar Battery Charger circuit. The most simple power systems with solar panels are composed of 3 parts: a diode, a solar cells system and a rechargeble battery. The diode prevents the battery discharging through the solar cells in the lack of solar light. Although the diode is often a Schottky type, the direct voltage applied on it can produce a high power leakage.
The featured solar battery charger circuit presented here uses a special diode with reduced direct voltage.


The OA OP60 consumes a very low current: 20mA. Although it can work with a 1.6V voltage, the T1 gate needs at least 3V to switch. To adjust the circuit, replace the solar cell panel with a adjustable power supply with the current limited at a low value, safe for the battery. Adjust the voltage supply at 0.1V higher than the dc voltage of the battery. Then, adjust P1 until IC1 output is “1″. At the end you can chech with an ampermeter is the battery is not discharging when the power supply voltage is under the dc battery voltage.

Solar Powered Battery Charger Circuit Diagram

Solar Powered Battery Charger Circuit Diagram
Solar energy is very cheap so buy solar panels