Solar Charge Controllers
If you have a simple off-grid setup with just one panel or even a few solar panels and several batteries, the other vital ingredient is a charge controller that regulates the power going from the panel to the battery and shuts off power input when the batteries are fully charged.
This makes the process of running your own power station almost maintenance free.
When you are starting up its best to buy a medium-priced controller so that you can add a few panels and batteries to the mix before having to upgrade. The HQRP 20A Solar Panel Battery Charge Controller / Regulator 12V / 24V 20 Amp 300W with PWM Type of Charging retails at under $50 on Amazon.