Electrics can be a sticking point if you’ve not got any experience. I was studying Electronic Engineering while doing my van conversion but to be honest the wiring is pretty simple and you make it as complex as you want. The general setup is to use a leisure battery so that you’re not draining your starter battery, meaning you’ll never not be able to start your van because you’ve watched films all day instead of being out on the hill!
Here the common practice seems to be: Van battery – fuse – isolator switch – split charge relay – leisure battery – fuse box – switches – appliances. This setup has several safety features that means my van battery is 100% safe; the fuse stops any large currents drawing the charge from my van battery, the isolator switch means I can totally disconnect the camper-van circuit from the original van circuit; the split charge relay only allows current to flow in one direction (ie it only charges the leisure battery, not vice versa) and it only charges when the van battery is above 12 V meaning always enough volts to start the van. On the other side of the leisure battery a fuse box protects the battery incase of any large current draws, the switches mean you can turn on and off appliances as you need them, and then your appliances vary from simple lights, usb chargers right up to fridges, TVs etc.
At this point, its a good chance to attempt to work out your rough expected current draw. Things like battery chargers and fridges/heaters are going to be your largest drains, while lights/water pumps and phone chargers are going to be relatively small. You can then start to figure out what your fusebox might look like, what your battery life is likely to be like if you’re stationary for a while. Running just a single phone charge, you’d more than likely get around 40 full charges before you’d need to charge your leisure battery.
Deciding what connections and where to put them is another thing to think about at this stage. It’s far easier to put more in at this point – once the insulation and lining, then bed and storage gets fitted, adding a socket on the opposite corner will be a very tedious task. I’d say the most common connections are 5V USB and 12V cigarette lighters, but installing an inverter from 12V dc to 240vac and having the standard British 3 pin socket available is also found fairly regularly. This latter method does mean you can just take your standard chargers but most appliances run off either 5v or 12v and purchasing these chargers can be fairly cheap.
I spent a while not knowing exactly what I wanted to do, and I actually installed most of my insulation and lining before getting round to the electrics. The leisure battery is located behind the drivers seat, in a separate compartment under the bench seat. This is probably the most obvious place to put the battery, for being close to the van battery and out of the way. As I’ve suggested above, I have used the fuse, split charge relay and isolator switch to protect the van battery and the same setup as above in the camper circuit.
The camper circuit compartment: Isolator switch, split charge relay, fuse box and breakout and battery box.
We decided that we’d be able to run everything off 5 and 12 V systems, and if need be, buy an inverter in the future. We also decided to limit the electrics to just lights and chargers. Having the rough van layout in my head I began trailing cables out. I installed a ‘master power’ switch between the battery and the fuse box, killing power to all appliances. This has worked really well in allowing us to just flick it off when we leave the van, knowing that nothing is charging and everything is safe. The fuse box contains 3 fuses; lights, usbs and cigarette lighters. We have 5 spot LED lights in the van on 3 different circuits; one for a single light in the side door entrance, one for 2 lights in the remaining roof space and the last for lights mounted in the back doors (for when the doors are open and you need some light in the back outside space). The latter paid of lights get used rarely, but they’re a great help when doing a late night pack/unpack or even just cooking in the evening. The 5v usbs come in the form of a double 2amp charger. I installed one at the near end of the bed, one at the far end of the bed and the other in the ‘cubby hole’ on the other side of the van. This meant I had good coverage overall and they all get used depending on what we’re charging and which end we’re sleeping. The cigarette lighters get used the least, but again I put these in in the near and far ends of the bed. The laptop and camera chargers are the most common use of these sockets and again, use both sockets depending on what we’re doing in the van.
Finally, I’ve installed a small volt meter which turns on when the master switch is on. This is great for easily checking the leisure battery voltage and deciding whether to keep it connected to the van battery for charging or to disconnect it. We cover a lot of miles and don’t really drain much of the battery so we tend to leave it disconnected at times so not to over charge it.
Looking back, what would I do differently? Well, recently its been annoying me that I’ve got to turn on the main lights to be able to see in the cupboards at night so i’ve been thinking about installing cupboard lights. We’ve also been considering having water on tap, rather than pouring from a 10L bottle which would mean installing a water pump, power and a switch to it. We’ve more than coped without these, but as we now use the van on weekly basis for the various events and places around the UK we go on the weekends, these small features would be nice.
A fridge? No, we didn’t install a fridge or even take a 12v cool box with use for either of our longer Europe trips. At times this would have been useful and driving for longer durations every few days we’d easily have had the ability to maintain a good leisure battery charge level, however again we coped without. It forced us to buy more local produce which was possible some of the most fresh and tasty food we’ve had.