12v supply

Hi

My toyota does not have 240v hook up but has an inverter 12v to 240v. I don't intend putting 240v hook up access but would like some 12v sockets of which there are none (apart from cig lighter on dash). It has 2 marine 110 amp leisure batteries, a fuse bank/connectors which has a couple of empty slots and split charge relay. Can I connect a 12v supply to the fuse box ?
was thinking of one of those 12v 3x cig bank connections ,taking off cig connector at the end and wiring directly to fuse bank.
Obviously I would have to put an appropriate fuse at the fuse bank.

https://www.dropbox.com/sh/qjwchq3i96cqzuo/AAAWSX4t5Wu7ZjWHOVyIH5VWa?dl=0

Can anyone help with 12v post ?

Hi Mate look on ebay there are loads some with usb for phone or camera charging put two on mine just connect to appropriate fuse, have put 2 on my SC

I don't see why not, use a 10A fuse and check for the connections (sockets) getting warm.

Thanks folkes

Still need help....I have a 12v socket but it has 2 wires..........one with a blue line on it which I assume to be the positive lead and the other just black which must be the earth. The fuse box has just one red cable from the leisure batteries on one side and the other side has yellow cables coming from them.There doesn't appear to be any place to connect the earth cable ?
I am stuck as going away or the weekend (our first trip) and no 12v to power anything.
The pics link at the beginning of thread show set up...has split charge relay and an inverter for powering 240v which I don't intend using. The only 12v is the cig lighter on the dash but don't want to drain vehicle battery.
I wondered if the earth from the 12v socket should go on the neg battery terminal ???.......clueless

The earth cable can be connected to any convenient bit of metal that forms part of the van, or is bolted to said van.

Note that the center of the socket should be connected to +ve via the fuse box, the outer metal ring should end up connected to the van body/earth.

Thanks very much just the info I needed