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

Let s eliminate the lithium ion because its nominal voltage is over twice the voltage of aa or aaa batteries.

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

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. The batteries are charging in series. 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. A 2v solar cell would be more appropriate for charging a single rechargeable battery.

There are restrcitions on the size of the solar panel that can be used. Then run wires from the battery to the charge connector making sure to match the positive and negative poles. I have 2 nimh aa batteries 1 2v 2050mah 1 solar panel at 2v 0 3w generating 150mah. To charge a battery with a solar panel connect a charge connector to the solar panel.

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

The battery capacity is 2450 mah with a nominal 1 2 v per cell and the datasheet is here. 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.