Almost everything in the van runs off 12V DC power, or can be plugged into a 5V USB port, which itself is connected to the 12V DC supply. However, some things need mains AC power. Some of those things will for the foreseeable future (a domestic vacuum cleaner, a charger for the cordless drill batteries, etc.). Some are heading towards a low-voltage DC future (small battery chargers, electric toothbrushes, laptops) but the ones we actually have still need 230V AC. For us, the main culprit is my laptop, which is not sufficiently modern to have a USB-C power port.
These inverters take 12V DC, ‘invert’ it to 230V AC, and provide (in this case 2) 3-pin sockets into which you can plug your appliances. In the case of the laptop of course, this has a transformer inside the power supply, which takes the power back to about 20V DC. So the whole chain is inefficient (there is a fan on the inverter to dissipate all the wasted heat, though ours hasn’t got that warm yet) , graceless, and involves trailing wires all over the shop. But it will do the job until the future arrives.
This inverter is of the ‘pure sine’ variety, which is apparently better for some fussy devices. It’s also overkill for our current power requirements (my laptop charger is rated at 60W), but I figured this would give us some flexibility in case we need it in the future. The only tradeoff, other than price (and they’re pretty cheap really) is that it’s quite big.
£130 from Photonic Universe (via Amazon) (affiliate link)