Darrenb:
Last question on this topic from me. Can I plug a four gang into my inverter,charge my phone, connect an external hard drive, use/charge my laptop and boil a kettle. Or am I a fire hazard
I`ve got a 4 gang adaptor in mine, it runs the phone charger, Laptop charger the microwave and a shiny silver 1500watt kettle all at the same time (with the engine running). i got a phat 3000watt pure sine-wave tho 
bazstan009:
As for cooking, I use single ring gas camping stove, lives in its own little box. Gas can be bought in some service stops but cheaper in pound shop or the like.
If you have one of these check the condition of the ‘O’ ring that seals the gas canister on a regular basis !! I had one of those and one trip when away for a fortnight my 24v electric kettle packed in so never mind use the gas stove in the cab on the engine cover, I pushed the lever down to connect the cannister but never heard the gas escaping as I had the radio on but when I went to ignite it … bloody ell 
yellow flames filled both footwells and burned the hairs off me legs up to me knees and singed my ankles (by the shores of Lake Constance and temp outside was up in the eighties hence wearing shorts an no socks!!) Allways been very careful with them type since 
Hi lads after some advice so judging by the brill posts already for me to use my tv (60w) and phone/earpiece charger i will only need a 300w inverter pref wired up to fusebox supply ■■? Some of our lads have the 300 but run kettles off them anyone know if this is advisable or dangerous i use the camping stove for my kettle. The lowest wattage kettle i can find is 600w so would prob need a 1000w inverter is that right ■■
If in doubt check the fuse that powers the 24 volt power socket, prob about 25 amp.
So 25(amp) x 24(volt) = 600 watt, but remember that is max.
Now you need to look at all the items you want to hang off you inverter (most will have a plate stating current draw).
If you are going to run a lot of electrical items while the motor is off it is a good plan to monitor battery voltage, some inverters will cut out if battery voltage drops to low but this can be just a bit to late to leave starting power.
Said it before but worth repeating, cold will ■■■■ battery life away.
bazstan009:
If in doubt check the fuse that powers the 24 volt power socket, prob about 25 amp.
So 25(amp) x 24(volt) = 600 watt, but remember that is max.
The other thing to remember is the wattage rating of the inverter is what it’ll supply at 230V, not what it draws at 12V or 24V.S o if it says it is a 300W one that is 300W or 1.3A at 230V. They’re usually around 80-85% efficient so it’ll be drawing more than it supplies, maybe about 350W at full load so it’ll be drawing 20 times the current it can supply from the 12V socket. The 300W 12V one Maplin sells comes with a 25A fuse so its going to be using way more than a cig lighter socket can provide and the fact they come with battery clips tells you all you need to know. A 150W mains inverter is going to be pushing it for a 12V cig lighter socket at full load but a 150W one is more than plenty to run a laptop charger.
some inverters will cut out if battery voltage drops to low but this can be just a bit to late to leave starting power.
Good advice. The Maplin ones cut off at 10.5V. That is actually a voltage low enough that it causes physical damage to a car battery. Leisure batteries are OK to be discharged that low but doing it to a normal vehicle battery usually knackers it to some extent, the first time you get made aware of it being the first overnight cold spell.
Best advice is to buy 12V/24V gear wherever possible. I’d just get this for the laptop and be done with it.