Hi Folks! I started out with wanting to add solar just to keep my batteries charged when the RV is in storage…and then it grew from there! I can get (3) 440w Panels JA Solar panels and I want to run them in parallel. My batteries can only take 60A charging so my thinking is use a 100/50 MPPT but …

You are at 12V and say that you can fit 3 x 440W panels = 1320W. At a nominal voltage of 12.0 this equates to 110A output to the battery. The default settings for the Victron MPPT Calculator is a maximum over panelling of 30%. An 85A output MPPT is the smallest fit as 85A x 1.3 = 110.5A. What you n…

Victron has a pretty sweet tool for figuring these details out here. MPPT Calculator - Victron Energy There is more to it than you are factoring here.

Yeah, I think I’m going to have to go with the 150/85… Now I’m wondering about what cable size I’m going to need…and it looks like I have to go series because the cable requirement for parallel seems to be 1/0…

See screenshot [Screenshot_20260812_062318_Chrome]

Thanks for the great reply! It seems that you’re saying the 150/85 is already on the small side. If so, then I feel better because I just ordered it :slight_smile: It was much more than I was planning to spend. I was originally going to go with two panels but got a deal on another one, only to fin…

[image] BobKones: I have a Multiplus 2x120, a Cerbo and a Shunt already installed. The best way would be to use three Smartsolar 100/30 with one Module th each. Than you can use smaller wires and you have 3 MPPs. They can deliver at best sun 90A. But you bought a 150/85. Because that ist too …

This comes back to proper design and functionality and I really like the sounds of it. I can return the 150/85 and am already using DVCC. What I don’t like about my design is all 3 are in series. I wanted parallel but this would not work due to cable size. Your design sounds like it’s the best! Ho…

How much can you overload a MPPT?

DIY

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How much can you overload a MPPT?

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