FAQs
Victron & Electrical Systems
What size battery bank and inverter do I need?
It depends on what you run and for how long. List your appliances with their watts and how many hours a day you use each one, and that gives you your daily amp-hours. Most RV and van systems land between 200Ah and 600Ah of lithium, with a 2,000–3,000W inverter/charger. If you'd rather not do the math, book a System Consultation and we'll size it for you.
Should I build a 12V, 24V, or 48V system?
12V is simplest for most vans and smaller RVs because everything runs on it natively. 24V or 48V makes sense for larger systems (roughly 3,000W+ inverters or big air conditioners), because it cuts the current in half or more. That means thinner cables and less heat.
Can I mix Victron with other battery brands?
Yes. Victron inverters and chargers work with most LiFePO4 batteries, including SOK and EG4. For the best monitoring and control, pair them with a battery that can talk to a Victron GX device such as the Cerbo GX.
What is a Cerbo GX, and do I need one?
The Cerbo GX is the brain of a Victron system. It connects your inverter, solar charger, battery monitor and DC-DC charger, and it shows everything on one screen and in the VRM app, including remote monitoring from your phone. It isn't required, but we recommend it for almost any multi-component system.
Do I need a DC-DC charger to charge from my vehicle's alternator?
In most modern vehicles, yes. A DC-DC charger like the Victron Orion protects your alternator, charges lithium correctly, and works with smart alternators. For high-output charging, a second alternator is another option.
I installed my system myself and something isn't working. What can I do?
We can help, even if you didn't buy your parts from us. We offer in-shop and remote diagnostics and troubleshooting on existing systems, including Victron programming, wiring checks and battery/BMS issues. Book a Diagnostic / Troubleshooting Consultation and we'll get to the bottom of it.
RV & Van Air Conditioning
Can I run a 12V air conditioner off my batteries all night?
Yes, if the battery bank is sized for it. Take our OutEquipPro 12V 11,500 BTU Rooftop AC with Heat Pump. Its inverter compressor draws about 22–62 amps at 12V depending on how hard it's working, so an 8-hour night typically uses around 200–400Ah. A 400Ah+ lithium bank, plus a way to recharge (solar, alternator or shore power), is a good starting point.
What's the difference between a 12V DC AC and a standard 120V rooftop AC?
A 12V DC unit runs directly off your batteries with no inverter, so it's more efficient and quieter, and it's built for off-grid use. A 120V rooftop unit needs shore power, a generator or a large inverter, and it uses more energy. A soft starter like Micro-Air EasyStart can help a 120V unit start on a generator or inverter.
Will a rooftop unit fit my existing roof opening?
Most of the rooftop units we carry fit the standard RV vent opening. For example, the OutEquipPro 11,500 BTU Heat Pump unit fits 14.1" x 13.7" or 14.1" x 14.1" cutouts, so it can replace a vent fan or an old AC. Check each product page for its exact opening size, or ask us before you order.
Where do you ship, and do you offer installation?
We ship within the 48 contiguous states. If you're in Alaska, Hawaii or Puerto Rico, contact us before ordering at info@cissolardesign.com or (772) 494-5238 and we'll provide a custom freight quote. We also do full RV, coach, van and marine installs at our Vero Beach, FL shop. Book a call to get on the schedule.