Basic power supply for arduino with 6x1.2V Nimh Cell and solar 2.2W panel

Post date: Nov 11, 2015 6:49:36 AM

vqFrom old Isun solar charger i have hacked the 2 solar panel to try to make a solar charger for 6x1.2V cell Nimh.

Form the net i manage to find some datasheet (poor one) of this Isun solar panel:

• 2.2Watt 290ma @7.4V 145ma@15V

7.4 V is not going to be enough to charge 6x1.2V nimh cell =7.2V so i'll try to put the 2 solar panel in series.

Schematic:

A diode type 1N4001 or equivalent is used to avoid battery current to flow through the solar panel when the solar panel voltage output is lower than the 7.2V of the Nimh.The capacitor will absorb the sudden change of voltage.

Measuring the Amps and the Voltage:

I connect an ampere-meter in series to the solar panel and a voltmeter in parallel to the Nimh Cells to measure amp and voltage of the circuit..

Conclusion:

At noon with full sun exposure the solar panel are producing 100ma and 8.4 V with the cells pack connected.

It wont be enough to fully charge the 7.2V nimh battery but it should be enough to maintain the charge on the battery and power one arduinp board.

Not bad for a solar charger that i bough some 15 years ago....