Charging 1 2v Nimh Batteries With A 2 Watt Solar Panel

The solar panel is rated at 1 w with a max load voltage of 6 4 v and the product page is here.

Charging 1 2v nimh batteries with a 2 watt solar panel.

Because most consumer devices use either internal batteries aa or aaa batteries. There are restrcitions on the size of the solar panel that can be used. To charge a battery with a solar panel connect a charge connector to the solar panel. I have 2 nimh aa batteries 1 2v 2050mah 1 solar panel at 2v 0 3w generating 150mah.

With the standard 0 7v drop of a diode you ll have 1 3v of charge voltage which won t be high enough for a maximum charge but a schottky rectifier diode selected for 0 5v forward voltage drop would get you 1 5v charging. My circuit to power a red led require 1 8v so i have to connect the batteries in series in order to light the led. Divide the wattage of the solar panel by the voltage of the battery to get the number of amps your charge connector needs to handle. The battery capacity is 2450 mah with a nominal 1 2 v per cell and the datasheet is here.

The batteries are charging in series. I actually tested the panel myself and found that in the best case with 90 000 lux full sun the max voltage was 5 2 v corresponding to a max current of 157 ma. A 2v solar cell would be more appropriate for charging a single rechargeable battery. Then run wires from the battery to the charge connector making sure to match the positive and negative poles.

It varies from 3 2 v to 3 7 v ni mh is 1 2 v and nicd is also 1 2 v. The solar panel being used is a 12v 40ma solar panel.