Hi there. Picking up our first motorhome next week and just figuring out what can be plugged on when. The unit has 3 pin UK plugs so I'm assuming when hooked up you could happily have a laptop plugged in. When not hooked up I'm assume that same plug doesn't provide power. I've seen lighter powered ones (presumably drains the van battery) that plug in in the cab. And other ones you have to wire onto the leisure battery yourself? Any experience galdly absorbed thank you.