Size relays, chargers, batteries, inverters, solar and hook-up loads with UK units, standards and safety checks the US tools ignore.
Browse calculatorsBuilt for UK campervans and motorhomes — mm², BS EN 1648-2, 16A hook-up, smart-alternator aware.
Size your VSR, cable & fuses — with smart-alternator & lithium safety checks
Alternator-safe B2B charger sizing for smart alternators & lithium
How much battery capacity you actually need
Continuous + surge watts to the right pure-sine inverter
Panel wattage by usage and UK peak sun hours
Will a 16A / 10A / 6A campsite bollard trip?
Most van electrical calculators are American — AWG wire, gallons, 30A shore power. CampervanCalc uses mm² cable, BS EN 1648-2, 16A hook-up, UK peak sun hours and smart-alternator/lithium safety checks so the answer actually fits a UK build.