Energy and solar panels

How to choose the power system for your motorhome

A properly sized system allows you to stay off-grid without relying on an electric hookup. The main components—solar panel, MPPT controller, leisure battery, and distribution panel—must be compatible with each other both electrically and physically.

Solar panels: power, size, and technology

300 W monocrystalline panels are among the most sought-after for motorhomes and vans because they offer a good compromise between the surface area required and performance. PERC technology improves efficiency in diffuse light conditions. Before purchasing, check the dimensions of the available roof space and the maximum weight it can support. All Black panels—with black frames and cells—are appreciated for their aesthetics without compromising performance. Among the brands available: ExtraSun and Antarion.

Charge controllers: MPPT or PWM

The charge controller sits between the panel and the battery, optimizing energy transfer. MPPT controllers recover more energy than PWM controllers, especially when the panel voltage is significantly higher than the battery voltage. The maximum current rating determines how much photovoltaic power the controller can process. Victron Energy is a leading brand with its BlueSolar and SmartSolar ranges; Votronic also offers products in this category.

Leisure batteries: AGM, GEL, or lithium

AGM batteries—brands available: Exide, Varta—are a proven choice for reliability at a low cost. LiFePO4 lithium batteries are lighter, have longer lifespans, and offer a greater usable depth of discharge, but require an integrated BMS and a charger compatible with the lithium charging profile. The capacity in Ah should be calculated based on estimated daily onboard consumption.

Inverters, battery chargers, and DC-DC converters

The inverter converts the battery's direct current into alternating current for 230 V appliances. The battery charger charges the batteries when connected to the mains or a generator. The DC-DC converter charges the leisure battery from the alternator in a controlled manner, protecting both the starter battery and the lithium battery. Victron Energy, Votronic, and Redarc offer products covering all three functions.

Distribution panels, sockets, and cables

The 12 V distribution panel centralizes the fuses and circuits for various systems; the CBE DS300 is a model designed specifically for motorhomes and caravans. For wiring, the cable cross-section must be chosen based on the current to be carried and the length of the run: insufficient cross-sections cause voltage drops and overheating. 230 V external CEE sockets for campsite hookups must provide the moisture resistance required for outdoor use.