Updated : 02/12/2018

                          Ideas on How to Wire your Camper van Conversion.

Whether you have a Volkswagen T1, a Citroen H van or a Sprinter, wiring your van will be more cost effective if you plan it well. This is not sales based, we don't do this type of work, it is aimed to advise only. 

Many people plan their Campervan Wiring piecemeal, they start with a Habitation area battery then add a split charge relay. Then a mains charger, then Lights, Gas heater blower controller, water pump, power monitoring, Solar charging of the Habitation battery, etc.

Each item tends to have it's own wiring, switches, fuses and control so by the end of the work you have several completely independent units with switches and fuses all over the van and little integration.

One thing often not built in is the ability for a 'one touch' isolation of every device from draining power when the van isn't being used. You don't need to go around turning everything off when you put the van away, just one touch shuts down all 12v.

As an example this Control Panel above contains most functions at just over £69.

The CBE PC100 controls the Water Pump isolation, lights, Main Power, Water level display for both Waste and Fresh Water, voltage of Habitation area battery voltages, Starter battery status (and charging), etc. 

You don't have to wire them all in, but for £69 it is nice to know they are easy to add later if you you want to.  See here for a supplier of a kit :   https://www.grasshopperleisure.co.uk/cbe-pc100-complete-kit-315-p.asp

One brand new 2018 Camper we saw had this Bonus PMS 3 unit on display inside the habitation area.

Why would you want to see the 230v RCD/MCB? We hide them under the stairs in our Houses?  But worse than all that, it's design is Caravan derived. The mains charger is also very poor.

If you look at the unit it has limited fusing, a main power On/Off and a switch to control the Water Pump. 

No ability to power off the Fridge, lights, Water level check, no decent battery status check, etc. 

Which looks more expensive and professional? The stylish CBE Display or seeing an RCD with 'torpedeo' fuses and switches that even a 1980's Austin Allegro would be ashamed of? When did any decent car manufacturer last use Torpedo fuses, probably about 1963? 


You can see how much more attractive the 'modern' Sargent EC160 is below?

No? I couldn't either but at least it does use proper fuses.

We also think it is a safety issue putting both 230v and 12v in the same steel box. 

The best Motorhome builders keep them separate and use insulated 230v Plastic housings, for obvious reasons.

The Two units above need to be 'on view as they contain the switches that operate the devices, so imagine what the wiring will look like running into those two units?

You would need to make special provision to hide the wiring behind panels, etc Ideally hide the whole ugly things in a cupboard.

Whereas on the CBE kit, the Display/Controller is actually attractive and has only a single cable going to it.

The photo below is of a Rapido Motorhome with the CBE 230v RCD/MCB (in a safe, separate Plastic enclosure) then a DS300 style 12v unit (controls all the 12v - the Split charging, Starter battery charging, Fridge control and power distribution, battery protection, etc), then the charger all located below the Seats/bed.

In the above the CBE wiring is a bit untidy, but it's out of sight. More importantly, it's easy to get to. If you box the wiring in on the British units to stop it being on view, you will be sorry. 

If you plan carefully from the start you can have an attractive sophisticated single control system that will actually be cheaper than a piecemeal solution and add value at sale time, because:

1. The wiring is much simpler to install and understand

2. It is 'structured', has the look of a Professional Installation by someone who knew what they were doing.

3. It looks expensive, giving the impression you did not penny pinch.

4. Saves space.

5. Easy to operate.

6. Easy for someone else to maintain.

7. When you come to sell, you maximise the resale value because it looks so good and not 'bodged'. A good integrated solution will be cheaper yet actually increase the vans value by far more that it cost to buy. 

CBE make everything for a Camper conversion, from the sockets to the TV Ariel, all match. 

Integrated and 'Professional'.


The CBE system has a very sophisticated charger that, unlike other kits from the crude Sargent EC160, is both powerful yet won't overcharge the battery. 

Some of the Sargent Campervan electric kits include a feeble 10amp, 13.8v charger that will take a month of Sundays to get a big battery charged, if it manages to do it at all. 

When the engine is started, the EC160 also shuts down all of the habitation area electrics, so you can't see if the Habitation area battery is charging from the Alternator, but the CBE  units allow everything to work normally, regardless of whether the engine is running or not.

Very important as it allows you to start the engine to boost the battery and still see the last minutes of the Rugby/ MotoGp. 

With the British built units, as soon as you start the engine, the TV and all electrics can power down. 

One other odd quirk with the Sargent EC160 box, it doesn't automatically charge the Starter battery and habitation battery simultaneously. You have to manually select the Starter battery at the control panel to charge it. 

The CBE are more sophisticated and will charge both batteries automatically, but giving priority to the Habitation area battery.

The CBE is also modular, if any main part breaks, like the DS300 main controller unit, a replacement from Grass Hopper Leisure is just £79 and easy to buy.

The display is only £69, the entire mains RCD/MCB is only £79, etc.

If you get an issue with the Sargent you have to buy the entire assembly at well over £200.  The Sargent 'all in one box' approach can make fault finding expensive.

The CBE is designed for easy, long term, low cost maintenance.

We think it is the best system by far.

When wiring your Camper Conversion, think big from the start, you don't have to include everything in your list but plan for it from the start. It will save money in the long term. You might be sure you don't want to know how much water is left it the Water Tanks, but the next owner might. 

This is how they used to do it in the 1980's :  https://buildacampervan.com/electrical-systems/

How much more professional does this look below, hidden in a cupboard, compared to all the wiring and fuses you usually see :

The unit above routes the charging to both batteries simultaneously. It controls the Fridge. it contains the Split charger. It holds all the fuses with the routing to Water Pump, lights, etc.

All in one nice neat box.

We repair most systems from the UK, Germany, Italy, etc. We know what is on the market better than anyone. More importantly we know what works and what breaks but we don't sell these kits, so this is independent advice.


Things to consider in your plan:

1. Most Camper vans do not get used every week so Starter batteries can get a bit depleted. Consider a unit that will charge both your Starter and Habitation batteries simultaneously.

2. Consider a unit that has a Solar Input port that will automatically distribute the charge to Starter and Habitation area batteries so you don't have the complexity of wiring it to both. 

3. Water pump control : If you have a water pressure switch based solution you will be able to use standard taps without a microswitch which simplifies the wiring enormously and means you save money on the taps. However in this type of system you need a pump isolation switch to deactivate the pump when the tank runs dry or for maintenance.

4. How will you control the Fridge when running on 12v/Gas/230v mains? Modern Fridges require 3 x 12v supplies, one to the 12v heater element when running off the Alternator, an 'Alternator spinning' D+ signal supply and a continuous 12v 'control' supply for the module that controls the temperature when running on Gas and 240v. Without this permanent 12v control supply the fridge will not work on Gas, 240v or 12v Alternator. 

Ok so I know you are only building a day van and don't want a Fridge but think about the next person who buys it. Including it in the plan now will cost just a few pounds but add a lot more to it's resale value. The CBE has built in Fridge control.

See our new web page on 12v compressor Fridges

5. A Space Heater, such as Propex, will require 12v supply for gas ignition and the blower motor. You might also want to consider thermostat control of the Blower as this can save significant 12v power  by switching to slower speeds when up to temperature. 

12v power will be the thing you most run out of, maximise every milliamp.

6. Kitchen sink/shower Water Heater

7. Tank level display

8. Battery condition/Life left/Alternator Charge current/mains charge current. Don't underestimate the importance of this as it is the only way of calculating what power is left in the battery and if everything is working as expected. 

monitoring power usage or Diagnosing issues requires information up front. If your system supplies it you can stop faults developing and fix them before they become a major issue.

Suggest you fit a £7 Wattmeter as it displays amps, volts, Ah, Watts, etc.  

Great for wiring next to the battery to let you see how many Ah you use a day/week, etc. 

Wiring another into the Solar feed lets you see how much Solar power you harvest in Ah per day or week, see the Solar power pages for more info.  Very easy to wire in, search for Wattmeter on ebay. Beware of some of the other units as they are not so easy to wire up.

Lots of companies can supply the CBE kit, Grass Hopper Leisure have given us great service.

It is well made, reliable, light weight, compact, cheap yet full featured. 

Spares back-up is among the best. 

We no longer support CBE equipment (it never broke down so we didn't get any work!!) but last time we saw such a solution, prices were around £299 for a full kit : the LCD Display, Mains charger, 12v controller fuse board, Mains 230v RCD, etc.

When you think a decent dual battery charger will cost around £150 on it's own, £300 all in isn't bad when it also includes 240v power as well.

Please don't fit a CTEK car style battery charger, like many seem to, and then wonder why the battery doesn't get fully charged and fails after 12 months, it's not the same thing at all as a proper Motorhome charger. 

A proper motorhome battery charger is designed to fully change a habitation battery AND the Starter Battery simultaneously, when required without either overcharging or degrading the battery.  Have a look at the web page How does a charger work?

One thing we do sell and recommend is this £29 device : The mains Power Master

Sorry it's not impartial, but I do have to pay the rent.       :)

Don't always listen to the Converters, as you will probably see as you look around, some are still in the 1980's -

"Allan, I have been reading your information on wiring your own Campervan Conversion and very interested in fitting the CBE PC100 kit but I have been told by Kirivans that it is not suitable for my model VW T6 2018 with stop start technology. 

Could I have your thoughts on this subject. I would like to fit the CBE kit as I think it is a good product. 

Kind regards 

N. E".

Our reply :-

"Hello, any habitation electronics system will work with a Smart/Stop/Start or ANY type of alternator. All it needs is a Schaudt WA 12125 (or similar) that fits into the Starter battery feed to the CBE.

This WA12125 always ensures that the CBE is fed with 14.4v, or whatever is applicable for the battery type you have installed.

You just wire the CBE as per any other installation and fit the Schaudt 'Alternator smart  charger' between the Starter Battery (even better from the Alternator itself) and the CBE

The CBE is twice the quality and functionality of the typical Sargent unit, so don't let them twist your arm.

I have updated the web page with this info when I get a chance so you can refer your 'supplier' to interrogate the above product which can be found on eBay.

Kind regards,

Schematics and other info below :


When you get to thinking about Solar, have a look at our 'Solar Hints and Tips' webpage. We used to install Solar, and still fix poor installations, but the Solar webpage is not about a hard sell. 

Again it is just free help.

When you get around to choosing batteries, they are not all the same. There are Lead batteries and lumps of Lead that are better used to chock the wheels. Yet our 'best buy budget battery' is also one of the cheapest.

Do I need to tell you we don't sell batteries, so once again, independent advice?

See our Battery Technology webpage for more info.

Enjoy your Camper Van, here is one we built a while ago.


What a great Camper Van this would have made, high top, twin axle conversion.