For the majority of solar shoppers, there’s no need to worry about charge controllers. Rooftop or ground-mount solar installations with a battery backup arealmost always linked to the electric grid, and in the case that your battery completely fills up, your excess solar energy will automatically reroute there.

       If you are interested in installing a small off-grid solar energy system with battery backup, you might need to look into a solar charge controller toensure that your battery is safely charged. For relatively small batteriespaired with low-output 5-10 Watt solar panels, a PWM charge controller should do the job. For more complex DIY solar projects with higher output panels, youmay want to consider a MPPT charge controller.