I use a 150w inverter which plugs into the 12v socket to charge my laptop and shaver up, phones and watches are charged up with a USB adaptor which also plugs into the 12v socket. A 150w solar panel keeps the battery charged up.
We have a device from CPC, it up's the cars 12v via a selector switch, so 15v, 18v, 22v or 24v whatever your Laptop requires, the unit comes with a whole bunch of connectors to fit just about any laptop.
Very handy bit of kit, and I often use it at work when I am on site, of grid.
We charge the tablet using a power bank. Have also plugged it into the car when using it.
Have also on occasions asked at the reception where they charge phones/electrical items for free/a small charge/ a donation to their chosen charity - often air ambulance or other very useful charity.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets