I have a self-converted van equipped with an all-in-one MPPT inverter that only accepts solar input between 120-450V DC. Unfortunately, I'm using two solar panels that typically output about 65V and optimally 75V. Given that my system is a Soec 15kWh unit and I primarily charge from mains (especially considering how dark and cold it gets here in the Nordics during winter), I was wondering if there's a practical way to increase the voltage without damaging the system. Is replacing my panels the only viable option, or is there a workaround? I'm pretty sure it'll be tough to find a solution since my setup was perhaps not well thought out, but I'd love to hear from more experienced users if there's any hope here.
4 Answers
Thanks for all the insights! I’ve decided to replace the panels and maybe use the ones I have for something else or sell them. I realize that while I could theoretically work around this issue, the effort seems unnecessary at this point. I’ll stick to mains power for now.
You might be experiencing a classic sunk cost fallacy here. Acknowledge the mistake and consider that pushing a flawed setup isn’t worth the hassle. With a van, system failures could lead to significant discomfort, so it might be better to sell what you have, research what’s actually necessary for your needs, and invest in the correct solution. Consider it a learning experience!
If your setup uses a 48V battery or lower, you could bypass the inverter and attach a cheap Victron Smart MPPT to charge your battery directly. These controllers need a bit more than 5V from solar compared to your battery voltage before they start charging, and Victron models in that category are relatively affordable and smart. However, this only works if you can connect outside of the all-in-one system.
That’s a good option if the system allowed for it. Since it’s an all-in-one unit though, this workaround might not be possible.
Quick question: does your Soec all-in-one unit have external battery terminals? If they do (typically found on the right side near the AC terminals), you can connect an external charge controller like a Victron directly to those terminals and the solar panels to the Victron. It's a straightforward solution for someone willing to try!

Yeah, I’m leaning towards getting new panels that’ll just work without complications. I just wanted to make sure I explored every angle first. The mounting process was the most tedious part, but I can handle getting new ones.”