Solar Charger for
6V 4.5Ah Battery
Here is a solar charger circuit that is used to charge Lead
Acid or Ni-Cd batteries using
the solar energy power. The circuit harvests solar energy to charge a 6 volt 4.5 Ah
rechargeable battery for various applications. The charger has voltage and current
regulation and over voltage cut-off facilities.
The circuit uses a 12 volt solar panel and a variable voltage regulator IC LM 317.
The solar panel consists of solar cells each rated at 1.2 volts.
12 volt DC is available from the panel to charge the battery. Charging current passes through D1 to the voltage regulator IC LM 317. By adjusting its Adjust pin, output voltage and current can be regulated.
The circuit uses a 12 volt solar panel and a variable voltage regulator IC LM 317.
The solar panel consists of solar cells each rated at 1.2 volts.
12 volt DC is available from the panel to charge the battery. Charging current passes through D1 to the voltage regulator IC LM 317. By adjusting its Adjust pin, output voltage and current can be regulated.
Solar Charger Circuit
Schematic
VR is placed between the adjust pin and ground to provide an output
voltage of 9 volts to the battery. Resistor R3 Restrict the charging current
and diode D2 prevents discharge of current from the battery.
Transistor T1 and Zener diode ZD act as a cut off switch when the
battery is full. Normally T1 is off and battery gets charging current. When the
terminal voltage of the battery rises above 6.8 volts, Zener conducts and
provides base current to T1. It then turns on grounding the output of LM317 to
stop charging.
