If you’ve gotten the opportunity to go camping, I’m sure you’ve considered how much better life might be with some extra power on hand. In my previous blog I began to expand on some of the basic components that you’d likely need or have encountered in your research. I wanted to go over some of the basics of how you should size your power system. Today we’ll begin to touch on how to size your power system.
If you’ve decided you want to either build or expand your power system for camping, the first thing that comes to mind is your battery system. I’m sure you’ve consider how many you might need or what type of battery may be best for you. Your battery setup is arguably the most important aspect of your system since it is what captures and delivers your power. To determine how many batteries you may need you need to first consider what you want to be able to run on a given day which means you need to get an estimate of your electrical load. You will want to look into the voltage of the components, total amperage draw, and will need to consider how long you will use your components for. The next step is to consider how long you need to be able to last without getting a recharge to your system. Depending on if you choose lithium or lead acid batteries, your depth of discharge for your batteries, or the maximum amount your batteries can be discharged, will vary. You will need to keep this in mind to make sure you are not draining your batteries past their depth of discharge.
To perform your calculations, it is helpful to convert everything to Watt hours. You can do this by first looking at the voltage requirement and amperage requirement of your components. If you multiply your volts by your amps you will get watts (VxA=W). Next you will want to multiply your wattage by the amount of hours in a given day that you will want to use the components to get Watt hours. For example, if I want to use a microwave that is 120V and 10A then it’s total wattage will be 1200W. If I expect to use it for a half hour before recharging my batteries, then the total watt hour requirement of this microwave will be 600Wh (1200W x 0.5). Most batteries will provide an expected deliverable Wh rating so you can then determine how many batteries you need. A common size for lithium batteries is 100Ah 12V (1200 Wh) so one battery would be able to run my microwave at least 2 times before recharging. There are a few other components that will be needed to build out a fully functional AC/DC system but we will touch on those in later blogs. If you have any questions please drop them in the comment section below!