Power Basics
Most campervans use 12V for lights, water pump, fridge, and charging. Power comes from the vehicle alternator when driving, and/or solar panels and leisure batteries when parked. A battery monitor helps you avoid flattening the battery. In NZ, solar works well in summer; in winter or cloudy spells you may need to drive or use a powered site to top up.
Solar Panels
Solar (e.g. 100–200 W) can keep a fridge and lights going in good sun. Fixed panels on the roof are common; portable panels can be angled toward the sun. You need a solar charge controller (MPPT or PWM) between the panel and battery. Size the system for your usage — fridge is the biggest draw. See living in a campervan for daily power use.
Batteries
Leisure (deep-cycle) batteries are designed for repeated discharge; don’t rely on the starter battery for habitation loads. AGM or lithium are common; lithium is lighter and can discharge deeper but costs more. Match battery capacity (Ah) to your loads and how long you want to camp without driving or shore power. Keep batteries secure and ventilated.
NZ Conditions
Sunshine hours vary — North Island and eastern South Island get more sun; West Coast and Fiordland are cloudier. In winter, shorter days and lower sun mean less solar harvest. Plan for cloudy days: reduce usage or use holiday parks with power. Diesel heaters and LED lights help keep consumption down.