Go for 3 volts instead and use small encapsulated panels in series and parallel for your requirements. Nicads are the way to go, charge them and let them run completely down, recharge them again. If you match your solar output to your daily usage you can just let them run down (like outdoor solar garden lights). Nicads can cycle everyday for 3 or 4 years or more without replacement.
You could get the system down to little money out of pocket, especially if you score cheap garden lights and use the batteries and leds out of them.[ Parent ]
