I’ve got my first night out and probably my only night out for a while tomorrow, I need something to do and also need to take my laptop with me. What is the best and cheapest way of getting power into my laptop for the evening in the truck ? Ta !
only options are the household charger with an inverter or a 12/24 volt charger , dont try and plug direct to truck system cos you may do some damage. charge it fully before you go to work and should last around 2 hours 
do a search for inverter. Seek and you shall find
where you night out going to be…if yer in a yard get next to gatehouse or near as pos and take an extension lead with yer…you could get an inverter if you night out more regular…
Thanks for the help, what price are we looking at for an inverter ? It would be handy to have one in the cab at any time to be honest.
About £30 from Argos for the 300watt.
Got mine about 5 years ago, still going strong now.
300w is a good size. Strong enough not to be working flat out to power your laptop
Maplins do a 12v 120w laptop power pack for £20 had mine for 3 year now never failed me and i can have my laptop on for about 4 hours before i brick it and fire the engine up. If you have a maplins where you live take the power pack in to the shop they’ll make sure you get the right one for you. 
I had my batteries down to 21v and the truck still started 
Hell mind you if you ever get a week away if your in dire need of your latop for 1 night lol … Ive a brand new argos inverter here, approx 350w, £25 inc postage if you fancy it?