Powering a single Device with 2 energy sources

Thread Starter


Joined Nov 16, 2007
Is there a way to power a device with Primarily solar, but in addition, when the situation occurs, with battery power as well?

In other words, If the solar energy is not sufficient, add the additional power from onboard batteries, NiMH, Lithium ion...


Joined Sep 21, 2007
That's easy and, in fact, it is what is normally done. The solar cells are dumping into the battery when they are active while the device is powered from the battery all the time. Same thing.


Joined Dec 23, 2006
Would you just place the Solar Cell in parallel with the battery with a diode to prevent current from passing back into the cell?


Joined Jan 10, 2006
In some cases yes, although it is good practice to put a solar regulator between the solar panel and the battery, especially if it is a higher power or 36 cell 12v panel, to prevent overcharging the battery.


Joined May 16, 2005
A common set-up is to have a photo-voltaic panel charging the batteries through the regulator Gadget describes. The batteries then feed an inverter to provide AC for common household conveniences.

The inverter is the usually weak link in the chain. If your device is DC, then no inverter is needed, of course.