Building an RV or Van Power System

Whether you are fitting out a camper van or a family RV, the power question comes first. Do you plug in a portable station, or build a fixed battery bank into the vehicle? This page walks you through that choice, then through charging and sizing for a fridge, fans and induction cooking.

Step one: portable station or fixed bank?

A portable station is a battery, inverter and charger in one box. You carry it in, plug it in and go. It suits weekend trips, shared vehicles and anyone who wants to take the power indoors or to a campsite table. It also suits renters and people who do not want to drill holes. The trade-off is size. Past a certain capacity, one box gets heavy and you pay for convenience.

If you already own a station, small 12V cables let it feed vehicle-powered devices that need more current. They are made for vandwellers and DIYers. Pick the cable by the station model, because each one is listed for a specific unit.

Step two: a fixed LiFePO4 bank

A fixed bank is built into the vehicle and wired to your loads. It suits full-timers and long stays off grid, where capacity matters more than portability. The choice is usually between 12V and 48V. A 12V bank matches the rest of a typical vehicle and suits smaller systems. A 48V bank (the B4810 is listed at 51.2 V, 100 Ah) carries the same power at lower current, which suits bigger loads and larger inverters.

The 12V batteries come in two sizes: 100 Ah and 314 Ah. The smaller one suits a modest build. The larger one gives a van more room for a fridge, fans and lights over several days.

For 48V, the RV5 is the core unit, and the B4810 is the battery you add to it. Batteries link with short or long connection cables, so think about where each one will sit before you order.

Step three: kits that bundle the pieces

If you would rather not pick every part, the RV kits pair the RV5 with B4810 batteries, an Epanel and an Epad. The 5kWh version has one battery. The 10kWh version has two. Some 5kWh kits add one, two or three 200W panels, so roof solar is part of the box. A kit suits a first-time builder who wants parts chosen to work together.

The kits with three panels, or with two, suit a longer stay away from hookups. Compare the panel count to your roof space before you commit.

Step four: charging on the move

Alternator charging turns driving time into battery time. A DC-DC charger sits between the starter battery and the house battery and manages the charge. The D40 is listed at 12V and 30A, up to 400W, and works with LiFePO4, AGM, gel, lead-acid and calcium batteries. That makes it a flexible choice for a 12V house battery.

For bigger power stations, the Charger 1 is listed at up to 560W, enough to fully charge a 1kWh station in about 2.5 hours. The Charger 2 is the bidirectional option, with separate cables listed for the AC240 and for FridgePower, plus a D+ signal wire. Match the cable to your unit.

Step five: shore power and roof solar

Shore power fills the bank quickly at a campsite, so it is worth having a charger that can use it. Solar tops up slowly all day and keeps the fridge running when you are parked somewhere quiet. Most travellers end up with all three: shore, alternator and roof panels. Solar is the one that decides how long you can stay put.

The Charger 2 with a 200W PV100FX panel is a bundle for those who want a starting point that mixes vehicle charging and solar.

How to choose

• Start with loads. List the fridge, fans and any induction hob, with watts and hours per day.
• Induction cooking is the big one. It needs inverter output well above everything else, so size the inverter for it, and expect it to drain a battery quickly.
• Pick 12V for a small, simple build. Pick 48V when the inverter is large and you want lower current.
• Count your charging sources. Alternator, shore and solar should together refill what you use.
• Check each cable and charger against the exact model name in the listing.

Questions people ask

Can a portable station run a fridge in a van?

Yes, if its output and capacity cover the fridge's draw over the hours you need. Check the fridge's watts and the station's specifications first.

Do I need a DC-DC charger?

If you want the alternator to charge a house battery, a DC-DC charger is the usual way to do it. Follow the manual for wiring.

Is 12V or 48V better?

Neither is better in every case. 12V suits smaller builds. 48V suits larger loads and bigger inverters.

How much solar do I need?

It depends on your daily use and how sunny your trips are. Add up your daily watt hours first, then choose the panel count.