The basic setup
A standard off-grid van setup has three components: a solar panel (or two) on the roof, an MPPT charge controller that regulates the charge going into the battery, and a leisure battery that stores the power. The leisure battery is separate from the van's starter battery - drawing it flat doesn't leave you stranded.
For most buyers, 200-400W of solar and a 100Ah+ leisure battery is the right starting point. That runs a diesel heater fan, phone and device charging, LED lighting, a 12V compressor fridge, and a USB socket for a day or two without sun before you need to drive or find a hookup - weather and usage depending. In practice, most UK trips get enough sun to top it up daily.
One tip if you have a pop-top: the roof angles when lifted, so think about which direction you park and where the sun arcs during the day. A few degrees of tilt can make a noticeable difference to your solar input.
Lithium vs AGM
The leisure battery choice matters. A 100Ah AGM battery gives you around 50Ah of usable capacity - drawing below 50% significantly shortens its lifespan. A 100Ah LiFePO4 (lithium iron phosphate) battery gives you close to 100Ah usable, lasts 2,000+ charge cycles versus 300-500 for AGM, and is half the weight. The upfront cost is 3× higher. If you're specifying a new conversion and plan to keep the van, the lithium upgrade is worth it. If you're buying pre-converted with an AGM, it's fine to start with - upgrade later.
Prices shown as a guide - they can change at any time.
Always check compatibility with your specific vehicle before buying. Van models, years, and conversion specs vary - we can't guarantee every product fits every setup. If in doubt, contact the manufacturer or your converter.
What to specify at conversion time
Ask your conversion company for: panel brand and wattage (not just "solar"), the MPPT controller model (Victron SmartSolar is the standard - it has Bluetooth monitoring), the battery type and capacity, and a DC-DC charger (also called a B2B charger) so the battery charges from the alternator when driving. A split charge relay is cheaper but less effective - insist on a DC-DC charger if you're spending proper money on the battery.