I'm new to solar power and want to maximize my off-grid living options. Currently, I have a medium-sized RV equipped with a 30-amp, 12-volt system. It has a 190w solar panel paired with a 1000w inverter charger, but the original PWM charge controller has failed. I've upgraded to a battery bank consisting of 3x 280amp 12v LifePo4 batteries and added extra panels for a total of 800-1000w, depending on whether I use my portable panel. Now, I'm planning to upgrade to Victron components, specifically a Multiplus II 50-amp inverter, but I want to know the best way to make my system flexible enough to transition to a 48v system when I move to a 40-foot sailboat in the next couple of years. I want to replace as few components as possible, including any necessary converters for my 12v appliances. Any advice?
3 Answers
I recommend going for a 24v system. If you add one more 12v 280ah battery, you could set up a 2s2p configuration to achieve around 14kwh of capacity. The Multiplus-II 24v version would also let you add more in the future. Just keep in mind, you may not have enough solar panels to keep up with your battery, especially if you want to avoid running out of charge. I run 1200w with 8kwh, and it’s tough to fully recharge a dead battery on a good day.
If your current Multiplus is 12v, switching to 48v won't work without a costly converter. You’d need a 48v to 12v converter strong enough for your needs, but honestly, it might just be easier to sell your Multiplus and buy a new one that supports 48v. Right now, stick with the 12v setup for your RV; it’ll be simpler in the long run.
Victron has you covered for multi-voltage setups with their DC to DC converters. If you’re only running lights or small appliances, a converter should be adequate. But remember, your batteries need to match the inverter’s voltage. Most of the Victron components are pretty flexible on voltage, so you're good there!