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

The batteries are charging in series.

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. 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 am working on a school project involving charging 4 aaa nimh batteries 1 2v each with a small solar panel used for outside lighting.

The solar panel is rated at 1 w with a max load voltage of 6 4 v and the product page is here. Let s eliminate the lithium ion because its nominal voltage is over twice the voltage of aa or aaa batteries. The battery capacity is 2450 mah with a nominal 1 2 v per cell and the datasheet is here. The solar panel being used is a 12v 40ma solar panel.

It varies from 3 2 v to 3 7 v ni mh is 1 2 v and nicd is also 1 2 v. 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. That thing i already understand the problem is that i can t charge the 2 batteries with the solar panel while the batteries are in series as. I have 2 nimh aa batteries 1 2v 2050mah 1 solar panel at 2v 0 3w generating 150mah.

A 2v solar cell would be more appropriate for charging a single rechargeable battery. 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.