If you wish to live off the grid, you have to install a solar panel charge controller. The purpose of this device is to allow you to charge your rechargeable batteries so they can supply you with electricity during the night.
The reason why rechargeable batteries cannot be charged straight from the output of the solar panels is because the voltage and current is not regulated. As such, there might be current spikes that may perhaps damage the batteries. Or the voltage may be too low, causing the current to flow into the solar panels instead. This will drain the stored energy from within the batteries.
A charge controller will keep the charging voltage relatively constant and direct the current into the batteries in a controlled manner. Once the batteries are totally charged, the solar charge controller will electrically disconnect the charging current from the battery to prevent overcharging.
When the batteries are fully charged, the charge controller can redirect the electricity to other loads or a different set of batteries. They can even be made to flow back into the power grid if you so desire.
There are many types of charge controller available in the market. Some are complex while others are simple.
When shopping for your charge regulator, you have to know what rating to buy in order for it to work properly with your solar panels and your rechargeable batteries. When in doubt, always double-check your ratings with the supplier or an expert before buying. Also, different charge regulators have different lengths of warranty. Be sure to check that the warranty is within your expectation before leaving the store.
Another good way to have a good solar charge controller for your solar power generator is to build one yourself.
This requires a little skill. But if you have some experience making simple circuits and soldering those electronic components onto a printed circuit board or a perforated board, you should do well.
You can find different circuits in books or on the Internet. There will surely be a design that is suitable for your solar generator. If you find it a hassle to etch printed circuit boards or cut perforated boards, you can always buy a do-it-yourself hobby kit that comes with schematics. In the kit, you’ll usually find instructions on where to place each component, a description of the circuit, how to use it and which project box to house your circuit board in.