Hey everyone! I'm currently working on sizing an MPPT for my campervan solar setup and could use some help checking my calculations to ensure they're safe. I plan to mount three 200W 24V solar panels in series on my roof, which have the following specs: each panel has an open circuit voltage of 38V and a short circuit current of 6.85A. My battery voltage will be at 12V.
Here's the math I have so far: the max voltage is calculated as 38V times 3 panels times 1.2, giving me a total of 136.8V. For the max current to the battery, I calculated it as 200W times 3 panels divided by 12V, which equals 50A. Based on this, I think a Victron 150/60 MPPT should work fine, right? I'd appreciate any feedback—thanks!
2 Answers
Your calculations look solid! Just keep in mind that if any of your panels get shaded, it can affect the entire series setup. Have you thought about installing micro-optimizers? They help by allowing the better-performing panels to keep producing at their best while shading affects others.
I’m not sure about your current calculation. You mentioned that 600W will go to the charge controller from the panels, which seems off since they’re in series. Just remember that while the voltage adds up in series, the total current remains the same as one panel. So you’re not multiplying the current here, just considering the total power delivered to charge your battery, which sounds right to me.
Thanks for clarifying! I think I misunderstood that part. Your points make it clearer. I appreciate it!
I get what you're saying. I'm considering series connections given my parking habits, but I didn't know about micro-optimizers before. I'll definitely look into that!