Solar charger via cigarette lighter on Fiat Ducato

I am thinking of buying a small solar panel to keep my battery charged up whilst in the storage compound over winter.   My problem is that there is not enough room in the battery compartment to use crocodile clips with which the panels usually are fitted.   Does anyone know whether it would be safe to run a cable from the battery terminal clips into the caravan to a cigarette lighter socket?   If it is, would it have to have a fuse in the cable between the battery and the cigarette lighter socket?

The cable from the battery  positive terminal to the cigarette lighter must be protected from a short circuit that could melt a small cable and cause a fire. The fuse should be mounted as near to the battery terminal as possible. If this is not practical then you must be confident that the short length of cable (no more than a few millimetres) between the terminal and the fuse is run in such a way that there is no possibility of it shorting to the negative terminal or any cable connected to the negative terminal. If I was installing the cigarette lighter I would fit a fuse to both battery terminals. I know many solar panel are supplied with croc clips to connect them to a battery but this arrangement is inherently unsafe and since the vehicle will be unattended for long periods of time its essential that the installation is safe to leave.

plug something in , easy check

Further to Dave Nicholson's response above, I am not sure whether he is responding to my query or to the owner of the Fiat vehicle.   For the sake of clarity may I explain more fully what I would like to do.   The battery compartment on my caravan is almost completely taken up by the 115Ah battery and the sprung clamp-on battery connectors.   I was considering purchasing a TP-solar 10w 12v solar panel (which comes with a regulator) in order to keep the battery trickle-charged during winter at a storage site about 10 miles from home.   As I could not use the croc clips which come with the solar kit I would have to permanently clamp the cable into the battery connectors.   I would then run the cable through the wall of the battery compartment (duly sealed around), across the floor of the under-bed storage area to a socket to be mounted on the wall of the storage area next to existing 13 amp and TV aerial sockets.   This would be a convenient place to plug in the solar panel when required. I had thought of a cigarette/cigar lighter socket for this but now wonder whether a 12v DC plug and socket would be just as suitable?    

Bob

As you say, the battery compartment is already taken up with the battery and I assume there will be no room for the solar panel regulator and I’d be reluctant to assume that the regulator is fused.  Your proposed arrangement will be fine either way ie. with a cigarette lighter type socket or a proprietor 12V DC plug and socket. However, you MUST still fit a fuse in the cable to the socket as near as possible to the battery positive terminal. If there’s space to fit an additional cable to the positive terminal for the socket cable then there must be space for an ‘in-Line’ fuse holder too. The solar panel you’re proposing to use is quite small and hence the charging current from it to the battery will be small too. The size of cable (in square millimetres) in theory need only be relatively small to carry the small current from the solar panel but in view of the fact that the cable is running under beds etc and through bulkheads you need to think about the robustness of the cable and the possibility of damaging it when items are resting on top of it. 

I suggest you use a length of 3 core flexible cable from the battery compartment to your new socket with a cable Core size of 2.5mmsq. (You will struggle to buy this in 2 core format so simply cut the extra core off at either end) and  fit a 10amp inline fuse/ holder inside the battery compartment as near to the positive terminal as practical. 

Your 3 core cable will be over-rated for its electrical duty (but it will not be easily or inadvertently damaged) and your 10 amp fuse will be more than adequate to protect the cable. I hope this helps but post again if you’re not sure. Electrical safety is important.

I was looking for the jump start points on my Carthago the other day but couldn't locate them. Not a lot of room under the lid mind you. Can anyone narrow down the search area?

Thanks for the reply.   Will try and set it up when next I can get the 'van at home.