Solar AA Battery Charger

Build A Simple Solar AA Battery Charger-LM317 Circuit

This is a solar panel charger schematic for AA and AAA rechargeable batteries. A small solar panel would be very good as a source of voltage charger. Building a solar AA battery charger only requires a few components and a simple construction.

This Solar AA battery charger has a serious limitation. Solar panels should be well adapted to the battery to be charged or the battery may be overcharged. If you want to charge batteries with different capacities, then you need to change the solar panels.

Since this is a simple solar battery charger that does not automatically turn off when the battery is full. So we need to maintain the charging current is low enough that will not damage the battery even when they are fully charged.

An LM317T voltage regulator chip that can be used with a suitable resistor to regulate current. See solar AA battery charger below:

Required resistor value is given by Ohm's Law as 1.25V divided by the required output current. (1.25V is regulated output from the LM317T ADJ's output.)

The higher the input voltage and current, the more heat will be generated by LM317T since the output current is fixed and the extra power to go somewhere. LM317T will overcome the current to 1.5 Amps and the like will have no problem at all with small solar panels.

Read more about LM317 Circuit and Alkaline Charger.