I'm planning to set up a solar power system with about 3000 watts of panels and need to purchase or build a battery pack. I'm wondering how the size of my solar panel array affects the size of the battery pack I should get. Specifically, does the array size influence whether I should go for a 100Ah or 200Ah battery? What's the difference in terms of charging time and power availability? Also, can I start with a 100Ah battery and later add a 200Ah battery to the same system?
3 Answers
It's crucial to first figure out your daily power usage to size your battery correctly. You generally want enough battery capacity to cover three days of usage without any charging, especially for cloudy days. Then, your panels should be sized to recharge that capacity within one sunny day. Starting with just one day's worth of batteries might be okay if you're planning to expand later. Also, think about having backup options like a generator for emergencies.
Just a heads up, you can't just mix and match batteries of different types and capacities into one bank. If you start with a 100Ah battery, that's fine, but plan ahead on how you'll expand without causing potential issues later. Also, make sure you know the voltage because that affects how you calculate your battery capacity.
The size of the battery pack really depends on how long you want your devices to run without sun. You should avoid running your batteries down too much by having extra capacity. Make sure your solar array produces enough energy to replace what you use each day. Oversizing your panels can take some stress off your battery and help with charging! Just keep in mind that mixing different battery sizes can be tricky since their maximum charge rates can differ.