Maybe a daft question, but apart from the obvious difference in voltage, what is best to use for in cab kettles & appliannces etc?
Does one heat up quicker than the other?
Need to get a kettle for nights out.
The trouble with kettles is they essentially short the current to heat the element, thus using loads of amps.
My understanding is the as the laws of physics suggest that I = V/R wher I is Current and V is Volts, if u up the Volts you reduce the current, a good thing!
Therefore for a kettle 24v is good… I think!
I await to be corrected!
P.s. If u use a 12v kettle and it blows the fuse DO NOT just up the fuse on the lighter plug circuit to 30amp say. You will fry the loom on your gaffers truck and risk setting fire to the dash (Here talks the voice of experience!) 
forget the electric kettle they take forever unless you have the engine running get a gas stove the type cdc sell in that black case and a kettle the stoves are only a tenner and a kettle will set you back a fiver
I agree with Carl there, but DO NOT pay £2+ each for the Gas. Argos sell 12 for £14 or try your local DIY/Camping shop, usually £4 for 4.
I wouldn’t bother with an electric kettle either… a gas stove is much quicker and you can cook your dinner on it too… 
As for anything else, I think most of my stuff can run on 12 or 24 Volts. My TV, mobile phone cahrger and sat nav can. I’d go for 24v though if I had to choose.
I bought a 24v Waeco kettle for about £35. It boils two mugfulls of water in about 10 minutes. It’s got a boil dry cut out and a mounting bracket that is screwed in the cab.
I just flick it on about 10 minutes before arriving somewhere, I’ve got my timing almost perfect now.
I bought it from Roadking, expensive at the time but well worth it (for me) doing days.
Carl:
forget the electric kettle they take forever unless you have the engine running get a gas stove the type cdc sell in that black case and a kettle the stoves are only a tenner and a kettle will set you back a fiver
and if you like toast in a morning you can get a stainless steel fold flat toaster for £3-4 to fit on/over the stove
tea and a couple of rounds of toast in a morning cant beat it 
don`t forget about the dangers of keeping both gas and other loose objects in the cab, they can do a lot of damage in the event of an accident
I use one of those flat gas cookers because I need all my sockets for computers, bluteeth headsets and phone chargers. Anyone who gets into TTZ can buy the gas cheap too
Another reason not to use electric kettles is that you dont know if someone has put a 3/8ths bolt in the fuse box, especially if you swap trucks a lot.
We have a direct feed from the battery to a normal european household socket which is always live so we can use this for fridges and microwaves but the Volvo sockets are still fitted and have 12/24
8wheels:
I bought a 24v Waeco kettle for about £35. It boils two mugfulls of water in about 10 minutes. It’s got a boil dry cut out and a mounting bracket that is screwed in the cab.I just flick it on about 10 minutes before arriving somewhere, I’ve got my timing almost perfect now.
I bought it from Roadking, expensive at the time but well worth it (for me) doing days.
Snap, i have and do the same, I went for the 24V as it will still run on 12V just ever so slowly, took 30mins to warm up just so i could have a pot noodle.
I would consider gas, if i spent more time away from home, but for me electric seams to work fine. its just a method of timing it right, and finding a good place to wedge it so that it doesnt go over and get hot water over everything.
we cant have gas after some ■■■■■■ blew thereselves up and burnt out the unit!!!