Updated : 24/01/2019

                        Ideas on How to Wire your Camper van Conversion.

                       (also useful if you are thinking of buying a PVC and want to compare build quality) 

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, 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 tubular 'torpedeo' style fuses and switches that even a 1980's Austin Allegro would be ashamed of? When did any decent automotive manufacturer last use that type of fuse, probably about 1983 and as a result, hard to find? 


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 there is a safety issue putting both 230v and 12v in the same steel box. 

230v in a steel shelled body isn't the ideal, but to then mix 230v and 12v is just plain silly.

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 all the 240v and 12v 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. 

Many Converters install them hidden away with difficult cable access.

Conversely, on the CBE kit, only the LCD Display/Controller is actually on display, it's attractive and has only a single cable going to it. Very easy to locate almost any where, preferably on view as it looks so smart.

The photo below is of a Rapido Motorhome with the CBE 230v RCD/MCB (in a safe, separate Plastic enclosure) then next to it a DS300 style 12v unit (this unit controls all the 12v - the Split charging, Starter battery charging, Fridge control and power distribution, battery protection, etc), then next to that is a proper motorhome 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, you may be sorry later. Remember that electrics and charging are amongst the most prolific issues on the motorhome Forums. 

Expect trouble.


If you plan carefully from the start you can have an attractive sophisticated 'single button' control system that may 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 on any of the work.

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. 

8. Safer. If electrical regulations say not to run 12v and 230v in the same trunking, think how that pans out in a steel housing which actually combines 12v and 230v?

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

Integrated and 'Professional'. This is an example of a CBE 13a socket, Audio and Tv 12v Power + antenna for both satelite and Digital.


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

Some of the Sargent Campervan electric kits include a feeble 10amp, 13.5v power supply (not a multi stage battery charger, but one with it's roots in the 1980's) that will take a month of Sundays to get a big battery fully charged, if it manages to do it at all. 

When the engine is started, the Sargent units shut 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, like a Generator does, and still see the last minutes of the Rugby/ MotoGp while the engine is running. 

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

One other odd quirk with the Sargent EC160 box, it doesn't simultaneously mains charge the Starter battery and Habitation Area battery. You have to manually select the Starter battery at the control panel to charge it and can only charge one or the other. 

The CBE units 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 Sargent Power supply that pretends to be a battery charger is so under powered it is prone to failure from overload.

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 it was done in the 1980's :  https://buildacampervan.com/electrical-systems/

Shame some still do it this way. 

You will find that even some 'professional' van converters don't put the customer first when it comes to electrics, but profit. Have a look around at some of the 'Big names' in the business to see how primitive some can be. 

We think one of the best guides to the quality of a professional conversion, is the electrics implementation.

We repair most Charger systems from the UK, Germany, Italy, France, Holland, 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. Just wiring it straight into the Power distribution/Controller box will ensure the wiring is simple, yet gets to both batteries.

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 Total Fridge control.

See our new web page on 12v compressor FridgesThese draw so much power, we don't think they are fit for purpose. There are very good reasons why motorhomes have had gas Fridges for 40+ years. 

A coolbox can draw a lot of 12v power over a 24 period, most of the bigger ones will discharge a battery in that time. We would suggest you calculate very carefully? 

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 monitor. 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 each 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 with a good reputation for after care. Their other website, Rainbow Conversions, contains more info on the CBE kit. 

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

Manufacturer 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 Habitation and Starter 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 charge 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

Voltage Sensing Relays.

If using a Voltage Sensing Relay for Split charging then note that the best quality batteries these days are 12.9v - 13.0v, yet most VSR's have not kept pace with battery technology and still behave like all batteries are the old fashioned Antimony based batteries with a 12.6v fully charged voltage.
They therefore 'disconnect' at 12.65 - 12.8v which will obviously keep the best quality batteries 'permanently' connected when the relay should be 'open'. 
See this example of a Durite unit showing the Cut-in and Cut-out voltages values on the label.

The unit below is a much better '2 Part' VSR, a £25 voltage sensing device that triggers a conventional 200Amp separate relay. This allows you to power the VSR from an Ignition switched supply to drive any 'ordinary' relay. 
When the ignition is turned off and the 'ignition' supply cut to the voltage sensing device, the relay opens regardless of the battery voltage.
You can additionally fit a switch to the 'Earth' cable to give you some manual control as well, see wiring diagram further down.

In the above diagram, the text reading "To Fused Supply" should read - "To Ignition Switched Supply", that is only powered when the Ignition is 'On'.
This will ensure that when the ignition is turned off the relay will open regardless of Starter battery voltage. 
At £25 it is more flexible than a Durite VSR and should be more reliable with lower voltage drop due to the huge 200Amp switch contacts.
See here for a potential supplier : 


An additional major advantage is that, when the 2 part VSR is wired as we suggest, it won't draw any power when the ignition is turned off. 

The draw of a conventional Durite VSR is only small, but enough to drop the Starter battery into the damaging 'Sulphation' zone in a couple of weeks, and enough to flatten the battery in about 4 weeks. 

A conventional VSR will always draw power 'looking' for the Starter battery voltage to rise above 13.2 so it can trigger. Because the 2 part unit above is only connected to the Starter battery when the ignition is on, there isn't the permanent current draw normally associated with a VSR.

Don't always listen to the Camper Van Converters, as you will probably see when 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 12145 (or similar) that fits into the Starter battery feed to the CBE.

This WA12145 always ensures that the CBE is fed with 14.4v, or whatever is applicable for the battery type you have installed. This type of device will be required for all electronic installations on a Stop/Start vehicle, regardless of who makes the electronics kit, be that Nordelettronica, CBE, Sargent, etc..

This isn't the only device, but it is the best. The Sterling supposedly similar devices are not the same at all.

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 so you can refer your 'supplier' to interrogate the above WA 12145 product which can be found on eBay.

Kind regards,

While the above unit is expensive, it is really powerful and quality and comes from the biggest Motorhome specific Charging electronics manufacturer in the World.

Note that the other Smart Alternator charger often proposed is the CTEK 250SA, but it only has a measly 20amps charge rate. For a typical twin battery set-up that is just 10 amps per battery so won't deliver the "faster charging" the advertising promises. 

To give you an idea of how poor it can be -

Example of CTEK 250SA charge rate.

Two 100Ah batteries discharged no more  than the recommended 50%. That equals 50Ah per battery that needs to be put back. At 10amps per battery it will require about 6 - 7 hours of driving. 

Note the CTEK 250SA charger won't be able to maintain 20amps for more than about 30 minutes before it gets hot.  20amps is it's peak, not continuous rating.

A one hour drive with a CTEK 250SA will put back just 10Ah into each battery.

Example of Schaudt WA12145 charge rate.

Two 100Ah batteries discharged no more  than the recommended 50%. That equals 50Ah per battery that needs to be put back. The Schaudt will achieve 22 amps per battery to fully charge the batteries in a 2 and a bit hours of driving. 

A one hour drive with a purpose made Motorhome/Camper Schaudt WA12145 will put back 22Ah into each battery.  45 amps is it's continuous rating.

The Schaudt isn't double the cost of the CTEK, but does have more than double the performance.

Note the above charging times will depend on many things from battery technology, age, temperature, etc and are the best, but the same criteria is applied to both examples above.

Schematics and other CBE 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, on the right below is the Citroen H van the my old company built a few years ago for the Wheeler Dealers TV program. It would have made a great Campervan.

Look out for it on  Wheeler Dealers episode (season 12, episode 16), short video of it here https://www.youtube.com/watch?v=XgD8Ejo-8jQ

The horsebox below was bought from France as the basis for an 'outdoor bar' we built for events. We knew when we bought it the entire chassis was rotten and needed a full reconstruction so the plan was to rebuild it as a long wheel base vehicle. We had started recreating the LWB chassis in the work shop even before the van arrived in the UK.

This was it after loading up in France :

We cut off the body and extended the 'chassis' to create this :


It really is the same van as the stumpy Horsebox above, just had Richard's and Arwel's magic tools 'waved over it'.

This photo below shows the interior of the same van after panelling by the team. All the work from rebuilding the body rewiring and plumbing in the sinks, all done in house.

And we rebuilt this van below from a wreck, the only UK built twin axle H van in the World :


Not only are we specialists in Campervan/Motorhome electrics, but you can see from above (and the Wheeler Dealers TV program that featured us) that we know about Interior construction, rebuilding engines, gearboxes, Brakes, Power Steering systems, Interiors, Starter Motors, Alternators, etc.

Not just the 'theory' but real world skills. How many Camper van converters can do all that?

In short every aspect of a Campervan or Catering vehicle. 

So when a converter tells you, "They don't know what they are talking about", you can show them this webpage and our old website that is now looked after by Richard and Arwel. 

Below is an example of a Rebuilt engine and Gearbox, all done in house, waiting to go to a customer :