Pure sine wave inverters provide premium power that is identical or even better than the power delivered by your electrical company.  Plugs directly to a 12V battery to power laptops, lighting, televisions, set top boxes and small applicances in your vehicle or caravan.  Mount it under your bed or inside your storage boot and optionally run a dedicated 240V AC power point so yiou have power at your fingertips wherever you are.  Of course you can position the inverter on a shelf in your van and plug directly into the 240V AC inlets on the inverter.  These are superb construction from Powerbright and feature anodized aluminium case with inbuilt heatsink, built in temperature controlled thermal fan, overload indicator, power on/off switch, 600 watts continuous power, 650 watts for 20 min, 1000 watts peak power.  These cannot be compared to the cheap inverters offered elsewhere.