Hey everyone! I've put together a DIY solar power system for my bus with a bit of research and guidance from the internet. Right now, I've got a Power Queen 30 AMP MPPT controller, four 100Ah 12.8V LiFePO4 batteries wired in parallel, a 2000/3500W peak inverter, and two solar panels on the roof. Unfortunately, I can't remember the specs of the panels since it's been a while and I don't have a ladder to check.
I have a couple of important questions: First, Power Queen says I can only connect up to four batteries in parallel— is that true? If I decide to get four more, can I set up a 4s4p or just go for an 8p configuration? Also, how do people manage 12V systems while their batteries are at 24V? The MPPT has a 12V output, but the current seems pretty limited, meaning I might need to keep it powered on constantly. Lastly, I'm struggling to find the maximum solar input the MPPT can handle— does anyone know? I really need more solar generation capacity since my current setup isn't cutting it for my power consumption, which includes a cheap TCL TV, a gaming PC with an RTX 4070, and an Alpicool fridge. I also use the system for lights, fans, and a water pump. Any advice on upgrading my system efficiently while being cost-effective would be greatly appreciated! Thanks!
1 Answer
It sounds like you're on the right track! Upgrading your solar array to four 305W panels in a 2s2p setup would definitely increase your charging capacity compared to the two 180W panels you have now. Keeping under the 100V range for the charge controller is key, and it should help you get more energy during the day. Plus, don’t feel bad about the 12V 100Ah batteries; many people start there. However, it’s true that four of those won’t keep up with higher power needs, especially with a setup like yours.
Absolutely, you've likely got enough battery capacity, but the solar panel output is falling short. Just do the math: with your existing panels, you'll need more than 13 hours of full sunlight to charge an empty battery bank. In contrast, four 300W panels can give you that boost and recharge everything nicely in just a few hours during good weather!