How many batteries to power a solar home?

Determining how many batteries you'll need to run your solar home is a matter of basic mathematics, as well as a little study of your electric bills. A battery will have its voltage and amp-hour capacity labeled on it. If you multiply those two numbers, you come out with the battery's capacity in watts. On your electric bill, you'll find the amount of electricity you consume each month. Some simple calculations will lead you to a figure for how much electricity you use each day.

Say, for example, that your home consumes 2,000 watts of electricity per day on average. You would logically need to reach at least that much capacity with your batteries to power your home. But here's the thing. You never want to overdraw your batteries, as you'll lose power and it will damage the batteries. Therefore, a good rule of thumb is to maintain twice the watt capacity in your batteries than your home consumes on a daily basis. So if you consume 2,000 watts per day, you'll want 4,000 watts worth of batteries. However many batteries it takes to get you to 4,000 watts is how many batteries you'll need to power your solar home.