Inverters

Most appliances in a campervan run directly from the 12v leisure battery. But some things like a kettle, a microwave, a laptop charger, an e-bike charger, simply need 230v mains power to work. An inverter converts your battery's 12v DC power into 230v AC, giving you a mains socket anywhere you park.

Choosing the right type

There are two types, and for most builds the decision is straightforward: go pure sine wave.

A pure sine wave inverter produces clean power that closely matches a mains socket. It is safe for all appliances including laptop chargers, induction hobs, air fryers, microwaves, and e-bike chargers. If a customer wants to go gas-free and run their cooking and charging from battery power, pure sine wave is the answer. It is the closest you will get to mains electricity from a battery system.

A modified sine wave inverter produces a rougher approximation. It works for very basic resistive loads but is not clean enough for many modern appliances and risks damaging or causing problems with the items listed above. The price gap between the two has narrowed, and the risk is not worth it.

Choosing the right size

Two numbers matter when sizing an inverter:

• Continuous rated power: what the inverter can sustain indefinitely
• Surge or peak power: the short burst it can deliver to handle the startup spike from motors and heating elements

Many appliances draw two to three times their running wattage at startup. This is because motors and heating elements require more power to get going than they do to keep running. A 700W microwave might pull over 1,500W for the first second. Size for the surge, not just the running load, and keep normal use to around 70 to 80% of the rated output to leave headroom and keep the unit cool..

Be realistic about battery impact

An inverter does not create power, it draws it from the leisure battery. A 2,000W kettle running for two minutes draws roughly 20Ah from a 12v battery. That is a significant chunk of a 100Ah battery.

The more you rely on mains appliances through an inverter, the more battery capacity and charging you need to keep pace. If you plan to use an inverter regularly off-grid, factor it into your battery and solar sizing. The inverter is also only as good as the battery and cabling behind it, if either cannot keep up with the current demand, the inverter will trip regardless of its rating.