Hook up cable

Your van should come with a hook up cable, sites do not provide them.

If buying one, get a 25 meter one.

Battery will be charged on EHU, and while driving.

An inverter converts 12v from the battery to 230v to power mains appliances.

You need your own mains cable, usually 25m long available from any caravan accessory shop.

The purpose of an inverter is to convert 12vDC from your leisure battery  to 240vAC.

Depending on the make and model of your camper the leisure battery is usually charged when the vehicle  engine is running.

Thanks . The inverter has an on and off switch . Do I leave this switched on all of the time . The sockets don't appear to work . Does this mean the leisure battery is faulty or discharged . If so is it ok to charge leisure battery as you would normally the car battery etc .

Where would be the best place to go for a new leisure battery if needs be . Cheers .

If things other than the mains-style sockets work then you leisure battery is working. But I would check you do actually have one, as some manufacturers in the past have economised and run everything off the vehicle cranking battery.

You engine should charge the leisure battery when it is running. It's quite possible the inverter has an additional switch you have still to find, or a fuse in the 12v supply to it is blown. If it is a big power inverter it may only work if the engine is running. Your inverter should be powering different mains-style sockets from those supplied by the EHU cable. In fact, I wonder if it is an "inverter" at all or is in fact the unit that supplies 12v from the EHU mains and charges the battery on site.

If you are going to buy a cable you might like to conside getting at the same time one of the short adapter cables that lets you use your EHU cable at home.  It has a normal houshold 13A plug on one end and a blue in-line socket on the other.  You can then run your outfit on mains at home.

Think this is what Navigateur above is referring to 

Mains Adapter

They can be handy

Could it be that the sockets don't appear to work because the van is not hooked up to mains electric?

More than likely  it's question been asked before.  If ..... the OP does have an inverter, rather than a 12v charger, I'd  have thought it would just supply a single socket, rather than all. Otherwise some would try to take power from them all at the same time.

do remember that if your hook up post is just behind your van , DO NOT coil it up, as it will overheat,

we also a 10 metre one, if its long enough we use that in not we use the long one

but we are now going towards off grid sites

You do not say what make the camper van is and how old. A dealer will always provide the orange mains hook-up lead and if bought privately the seller should have given you it.

An inverter is fairly rare and would be a retro-fit. As stated above, maybe it's the charger you are referring to. Seems a long read of the manual is in order!

The inverter should normally be switched off. Have a look and you will see it has 1 or 2 power sockets of the domestic 3 pin type. These can be used for low power 230vAC appliances when your camper is not connected to a 230vAC supply, by converting the battery voltage from 12vDC to 230vAC. Look at the inverter and you will see the output rating - likely to be very low i.e. 100watts or so. The 3 pin sockets elsewhere in the camper will not be powered by the inverter, so they will only work when the camper is connected to a 230vAC supply.