Having a steady supply of power is probably one of the most important factors when it comes to living in a camper van. When I first started out on the idea of doing my own conversions, one of the first thinking I started to look up was how to power all the gadgets & accessories when your on the road that you will need to live a comfortable life style.
So after some well researched planning, I have come up with the list of items I need to install giving me enough power for me to live in the van from a stationary position for a couple of days without charge.
I am hoping one day to add a 240v supply to run more appliances but as for now, this will do.
The place to 'store' your power...
So first and foremost, you need somewhere to store and access your power. It’s all about leisure batteries, which are specifically built for this purpose. Now they are a bit different to the ones that are located in your engine. Ok, going to get a bit technical but stick with me.
Engine Batteries (crank batteries) are designed to start a vehicle are made differently from batteries specifically intended to run camper appliances. This is because their operating requirements are a bit different.
For instance, a vehicle battery has to provide a high current surge to start an engine, but once that has been achieved, a vehicle’s alternator immediately replenishes the power it provided.
This is where a leisure battery comes in to there own. They have to provide a steady flow of current over a prolonged period.
I went with 2 x SuperBatt LM110 leisure batteries, each giving 110AH of power storage capabilities. I installed the batteries in a parallel configuration, giving me a total power storage of 220AH.
12 INTELLIGENT RELAY + KILL SWITCHES
The what now?
Ok, so now I have sufficient power storage with my 2 leisure batteries. That should hopefully give me a good amount of electricity to keep my electrics all running for at least some time, but what happens when you start to drain the leisure batteries using all the electronics? How do I go about recharging the 2 leisure batteries back up?
As I am not going with solar (as of yet) or not wanting a mains hook-up (connecting back to the grid) the only feasible way to recharge the leisure batteries and replenish the used power is to connect the leisure batteries to the van’s crank battery.
To do this it is actually quite simple. All you do is run a 12v positive wire from the crank battery through the van to the leisure batteries located in the back. When your engine is running, the alternator will kick out about 14v +/- 5% of power that then leaves the alternator, travels to the crank battery, then travels down the 12v wire, and will now charge the leisure batteries as well as the crank battery simultaneously. Tho this sounds like it ticks all the boxes there can (and will) be problems!
What happens if I am parked up for longer times than usual? I could accidently use all the power out of the leisure batteries. With flat leisure batteries, I would then run the risk of taking all the power from the crank battery. I would now have no way to start the van engine back up to get the alternator running that is needed to replenish the lost power back into all the batteries. This can be a big problem as if I am ever in remote locations, becoming stranded can be dangerous. This is where the 12v intelligent relay comes in handy.
You simply fit the relay between the 12v positive feed you made before from the crank battery to the leisure batteries. I also took this time to install a 12v kill switch located behind the driver’s seat just in case I wanted to kill the power coming from the alternator to the leisure batteries.
With the relay now in, this allows the leisure batteries to take power from the crank battery as normal when the engine is running, giving all the batteries a good charge, but if the crank battery should drop to a certain voltage (I think its around 12.4v, or when you turn the engine off) the 12v intelligent relay will detect this and will switch off the feed cutting the power. This then stops the leisure batteries taking any more electricity from the crank battery. This prevents you running your crank battery flat so you know you will always have the power there ready to start the van back up!
Thats why its a 12v intelligent relay, simple!
12V FUSE BOX
So, you have the batteries in, the intelligent 12v relay is installed so the van never gets a flat battery, so now it’s time to start hooking up some wires, and this requires a good fuse box.
Once again it comes down to good research, as the fuse box I bought I personally believe is the best money can buy. It is perfect for everything I will require. I went with the Ripca 12/24 Volt Fused Power & Earth Distribution Board. The beauty of this fuse box is having one positive bus and one negative all located on the board.
Basically it consists of two separate positive banks of 6 inline fuses with screw connections with each bank of fuses having 1 common feed for main positive connection. (ELI5: You connect the positive of the battery to one nut at the bottom of the board, this then splits the power to individual screw connections ready for whatever I need to connect to them, easy peasy!).
Another good thing about this fuse box is that it has a common busbar for the negative connection. (ELI5: Pretty much what I just mentions about the positive, except this is for the negative, so I only need to connect one main negative from the leisure batteries to the fusebox and now I have 6 screw connections I can connect all the negatives too!)
It also comes with a handy lid to keep it all safe.