The solar panel based charger described here is capable of charging Lead acid, Ni-Cd And Lithium-ion batteries. This circuit diagram is designed for a solar panel which is capable of delivering 5W power. The solar panel outputs 16.5V. It can deliver a current of 300-350 mA.lead acid, Ni-Cd and Li-ion. The lead-acid batteries are commonly used in emergency lamps and UPS.
|Circuit Diagram of Solar Charger : Right Click >> View Image to view full size|
Working Of The Circuit
The output of the solar panel is fed through polarity protector diode 1N5402 (D1). The battery charging current can be monitored via ammeter connected in series between diode D1 and the fuse. Diode D2 is used for protection against reverse polarity in case of wrong connection of the lead-acid battery.
The circuit can charge the following type batteries with rated voltages.
A. Lead acid 12 volt battery
B. Ni-Cd 1.2V - four cell
C. Li-ON 3.6 volt Battery.
To charge a lead acid battery, shift switch S1 to ‘on’ position and use connector ‘A.’ To charge Ni-Cd cells, put switches S1 and S3 to ON position and use connector B. Note that IC 7806 act as a constant current source. Resistor R2 limits the charging current.
To cahrge LI-ON battery, shift switches S1 and S2 to ON position and use connector C. Regulator IC 7805 (IC2) provides 5V for charging the Li-ion battery.