Beginner questions re. Victron 75/15 , Lifepo4 and solar setup for RV
I have a camper/trailer that I plan to set up with the following equipment and need advice on the installation. I will use it to power just led lights, water pump, exhaust fan and minimal draw from usb charger, and refrigerator control panel ( not to power the refrigerator) when camped without electric hookup.
System consists of: Victron 75/15 mppt controller, lifepo4 100ah battery w/ bms and bluetooth. I have 2 100w renogy suitcase panels that I would possibly like to wire/connect in parallel for powering the system.
The system would “top off” the battery which should be charged close to 80% from the tow vehicle when driven to camping destinations, But Also charge the battery when camped without electric hookup. Alternative plan would be to purchase a 220w suitcase panel ( for ease of setup and space) to use instead of the 2 100w suitcase panels and sell or save them for another project. In either case would it be better to use a Victron 100/20 controller or will the 75/15 be suffiecient ?
fyi: you also can use solar panels used for house roofs for a static mount because you might be loosing power in the wiring of the panels when searching for a good spot with the suitcase panels.
The two 100w suitcases each have an optimum operating voltage of 20.0, as does the 220w suitcase….the open circuit voltage of either are both @ 23.6-24v
Then the 75/100 should do fine. i would connect them in series though (and double the voltage) as the solar voltage needs to be a few volts higher than the battery voltage to start the solar charger in the morning.
The single panel would not be very useful in this case.
I have 100/30 with a 200W panel. I will typically get about 1kwh on a sunny day. If it’s cloudy and peaks will go just over 15amps. The 75/15 will be ok but at its limit most of the charge cycle in good sun. The 100/20 is far superior with a large heatsink and 48v and 36v charging options. I would go for the 100/20 they are not much more expensive or larger.
I have the same Victron/100 Ah lithium setup on my truck camper, except I have 2 panels in parallel for 225 watts of solar on my roof. So, my charge while driving comes from my solar. I only power what you plan to, nothing high powered like a microwave. Even though I have a DC-DC charger installed, but have never had to use it. I do almost all of my camping in the six months around summer in the US West. I stay primarily in forest service campgrounds and almost never in RV Parks with hookups. Based on my experience, I think you’ll be very pleased with your setup. Safe travels.
