I'm on to power inverters now.......

Onw CAN run a high wattage inverter from a cigar lighter socket as long as it is asked only to provide a low amount of power. It will draw but a small current.  As these sockets seem to be protected by 5 ampere fuses they can provide 60 watts. Pass that through the losses in an inverter and its cables and you have a maximum useful power about 55 watts even from a 4kW inverter.

Fitting the inverter permanently is a sensible idea as proper cables can be run from the battery to the inverter. As close as possible as the 12 volt losses are higher than at 240 volts per length of cable. I connect my inverters through the (smaller) size of Anderson Connectors (eBay will show you) so I can easily swap batteries about. 

The inverter powers some wiring seperate from the 240v EHU supplied wiring which goes to a second socket beside the microwave. Espresso machine and hair rollers can also be used on that socket, but not all at the same time!

Whilst an inverter will do the job, it is very inefficient - convert 12v to 240v and then get the laptop power pack to convert it back to 12v.

I suggest that you research "kensington 12v laptop charger" as these are designed to do the job you require from the cigar lighter socket.

Hi Rosie.  It would be better for your battery to charge your phone, tablet and mobile broadband etc during the day when there is free energy going to waste as your battery is already fully charged.  Charging overnight is drawing current from your battery which is not then being replaced until the next day.  Sometimes you have no choice about charging overnight, but choose daytime if you can.

convert 12v to 240v and then get the laptop power pack to convert it back to 12v.

Unfortunately that does not work as the typical laptop - as opposed to tablet - requires 18 or more volts to charge.

There are laptop chargers that do it straight from 12 volts but the last time I priced one I could get a decent inverter for the same money - and it would run other things as well.

If you just want to power a laptop and charge phones etc. I use one of these been running my laptop been quite well for the last couple of years.

http://www.ebay.co.uk/itm/12V-DC-to-240V-AC-150W-Power-Inverter-USB-Car-Boat-for-PSP-NDS-Laptop-Charger-WS-/263012633230?epid=0&hash=item3d3cc64a8e:g:5fkAAOSwLVZVlTiC

Although I am always cautious of buying and using anything to do with mains or 12v that comes direct from China.

Maplin do an equivalent :https://www.maplin.co.uk/p/ring-automotive-mp60-12v-modified-sinewave-45w-inverter-a88uk

Not wanting to sound rude but your electric will not be free unless you were given your solar panel, i am interested in how long it will be before you get a return on your investment never looked into having one fitted and it would be interesting to know.

Dreamer1 this thread may offer you so idea

https://www.caravanclub.co.uk/club-together/discussions/welcome-hobby-talk/tips-for-making-caravanning-touring-cheaper/whats-it-cost-to-get-ehu-free/?er=P453236#P453236

Our motorhome had a solar panel on when we purchased but it's only since reading the thread how to survive with ehu have we really appreciated it's worth. Just a decade 😲. But no articles in very layman's terms we just thought it was great at keeping the alarm battery and engine battery topped up. 

For us the payback was instant because it meant we weren't shackled to the Orange cable. 

Dreamer, The fitting of a 135w panel, an extra 110ah battery and a 2000w PSW inverter in 2013 was the best thing I have ever done in my caravanning life! As Boff says, it all depends on how you look at it. I quite agree with him that the payback is immediate from the point of view of freedom from the umbilical cord. Purely in monetary terms though, every night I spend away approximately £8 - £10 is saved give or take. So I guess the first 85 nights were payback. Don't forget this was 4 years ago- prices have fallen well since then. I now camp at a third of the price I used to and am no worse off comfortwise A Safefill cylinder has also added positively to the experience. Again, around £150 for a cylinder isn't cheap but then you realise that you will save many many times that with cheaper gas for the lifetime of the cylinder which, looked after, will be decades. As others have said, seek out the non EHU threads - happy reading- I think if you approach it in a positive way and not in a unbelieving and mocking way you will get a lot out of it. Many of us now are turning to non EHU and finding not is it possible but extremely satisfying and so so much cheaper. Good luck.