Solar powered battery charger
This solar charger circuit is used to charge a twelve-volt, lead acid battery. The battery in turn, can supply any device within its power capacity.
This circuit will charge a variety of SLA batteries up to about 3 Ah. The circuit will reduce the charge current as the battery reaches its Vmax, and the comparator shuts off the MOSFET. You will need the Vmax spec for the battery you are using.
Adjust the potentiometer until the point where battery voltage equals Vmax and current no longer flows. Placing the circuit and solar panel in a reflective, hinged box will boost output and protect the panel when not in use.
The original design is from the web, by Oscar den Uijl, odu@xs4all.nl at http://www.electronics-lab.com/projects/power/031/. I eliminated some parts and added a charging current meter.
