Solar charge controller- LM317 + Battery over charge controller (1.5A Max) -02 |
When the battery voltage reaches a fully charged voltage set by P2, the Op Amp turns off the voltage regulator.
This circuit is similar to the tool charger circuit except that the op amp is driven by the battery as a solar panel cannot be counted on to supply a steady voltage. Normally voltages will go up and down with the brightness. The regulator should deliver the same current, but limit the voltage supplied to the battery to 14 volts. The voltage regulator may need a heat sink if it gets too hot to touch and could melt a breadboard! BC547 transistor can be substituted for the 2N2222