Battery Sizer - Calculate needed batteries and UPS

How are amp hours calculated?

How do you calculate how long a battery will last?

How can I tell how much battery is left on my laptop?

How do you calculate battery watt hours?

How much storage you would like your battery bank to provide? Base this on the number of days your system will have to provide power without solar input. How many cloudy days in a row are typical for your location? Do you have an alternate source of power—grid intertie or generator—during these days?

Getting the right size battery. It's not good for batteries to be completely drained (ever), nor is it good for them to be consistently undercharged. It is best to size your battery bank so that it gets regularly charged to capacity.

If you are installing a system for a weekend home you may want to consider a larger battery bank, because your system will have all week to charge and store energy. Alternatively, if you are adding an array as a supplement to a generator-based system, your battery bank can be slightly undersized since the generator can be operated if needed for recharging.

When you sized your solar panel array you were dealing with watts per hour that you need to produce. Now you will be dealing with amps per hour that you need to store. Remember watts = volts X amps. Now grab a calculator and do the math..........