Tag Archives: Caravan Electrics

The problem with information from the internet…

08 Sunday Dec 2019

Posted by in Caravan Electrical Fault Finding, Caravan Electrics, Electrical, Modifications, Motor Home, Technical

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The problem with information on the internet is that although there is some great advice to be found there is also some less than great…. poor… really really poor advice and sorting out the good from the bad is sometimes not easy.

We are currently pitched on the Caravan & Motorhome club site Beechwood Grange near York and I decided to sit down and pen this post as for the last few months I seem to have been sorting out a number of problems via emails and phone conversations that really should not have arisen.

I’m going to give you a couple of examples of what’s been dropping in my inbox. To protect the inoccent I’m not going to name anyone or the channels. I do have the OK to relate these issues.

Case 1

“Hope you can help, I’m converting a VW Transporter into a camper van and have been following a number of YouTube channels for information on how to do it. It’s nearly complete but I have a problem when I go to use my inverter off grid. The base of the seat starts to warm up and a get a funny smell in the front of the van”

After an exchange of emails and a few photos were sent I eventually worked out what was going on. The 2000W Pure Sine Wave inverter was floor mounted in a cupboard towards the rear of the van where it was convenient for the mains sockets on the inverter to be reached. A suitable size Positive (+ve) lead ran back to the two 100Ah AGM batteries located under the front seat. A suitably sized Negative (-ve) lead also ran back to the batteries and was bolted to the chassis under the seat along with a number of other smaller -ve leads. The batteries were mounted on a wooden platform above this connection. The +ve lead from the inverter went to one battery +ve terminal and a link wire to the second battery +ve tied the two together. The size and rating of this tie wire was a lot less than it should have been.

The -ve posts of each battery had a very short 10mm2 cable going to a threaded stud mounted on the base of the seat and were helpful on to the stud by a star washer and nut. The seat base was a 3rd party metal fabrication hat had been powder coated and bolted to the vehicle floor by 4 bolts and ‘penny’ washers.

What was going on?

When the inverter was operated, it drew current from the battery down the +ve lead. Apart from the fact there wasn’t a fuse between the battery and inverter this side of the circuit was OK. The return path however was a different story. The inverter -ve lead was connected to the vehicle chassis under the seat – not at one of the seat mounting points. The -ve of the two batteries was connected to a stud that was a press fit into the seat base. It didn’t have a hexagonal head just a mushroom head. It was also way under size for the terminals that were fastened to it. The oversize star washer stopped the nut pulling through the terminals. The return current path therefore had to flow into the vehicle chassis, up the four bolts holding the seat to the floor and through the seat base to the push fit stud and finally into the two short leads connecting the battery -ve terminals. The relative high current drawn by the inverter through the single undersized push fit stud and the four floor bolts that were securing a powder coated frame with penny washers presented enough resistance for 60 or 70 Amps of current to start to heat things up a bit and burning off some of the powder coating. 70 Amps passing through a 0.1 ohm resistance will generate 490 watts of heat (calculated using R x I2 = P) this is why it’s critical to get any cabling correctly crimped with the right terminals for the job.

Conclusion

Don’t rely on the vehicle chassis as a return path. install cables for both ‘legs’ of the circuit from source to destination and back again.

There wasn’t a fuse installed near the battery. Any cable coming from a battery MUST have a fuse close to the battery before it goes off anywhere to supply anything else.

If a cable terminal requires an M4 nut and bolt…. use an M4 bolt nothing smaller will do.

If you are ‘grounding’ to anything metal, clean the surface, use a dab of protective dielectric grease (there are different ones for steel and aluminium!) and make sure any washers used work correctly. Flat clean washers for electrical contact and a star washer as a mechanical anti vibration measure to stop the nut loosening.

Case 2

“When ever we have been away for a few days off grid on the return trip there always seems to be a strange smell coming from the engine compartment. We have a self converted T6 camper and 400Ah of AGM leisure batteries with 240 watts of solar on the roof. After watching a couple of YouTube installations of DC to DC chargers I recently installed a Redarc DC to DC charger to help keep the leisure batteries in good condition and fix some issues I was having with the smart alternator”.

OK again after several email exchanges and a couple of video clips I got to the bottom of this one as well. The RedArc unit is capable of charing at 50 Amps and to do this pulls around 55 to 60 amps from the vehicles alternator. However there are a couple of issues in doing this. One of the first things that the Car Audio guys always recommend before installing any of the mahoosive bass pumping amps in vehicles is to replace and upgrade three essential cables. The first is the cable from the alternator output to the battery, the second which might not seem so obvious is the ‘earth strap’ as it is sometimes called from the engine to the vehicle chassis. This need either replacing completely with a larger cross section and also where it terminates on the vehicle needs altering. Usually the Audio boys install a new cable from the alternator mounting bolt directly back to the negative battery terminal*. Why” Well quite often the engine earth strap is just a simple copper braid strip sized just big enough so the starter motor current won’t burn it out for the 5 to 10 sends the starter is operated. You start trying to push the engine battery charing current and the additional 60 amps for the DC to DC charger through it, it starts to get warm. Not a problem as usually it’s not covered in a PVC jacket and hanging down in a bit of air flow under the engine. So the Audio guys change or upgrade it and they pull more current than we do. The third and last one that is upgraded is the short stubby battery negative lead going to the vehicle chassis. For our purposes, not really a necessity but hey ho.

*A note of caution. On most vehicles now there is a shunt between the large negative cable going to the battery and the negative terminal of the battery. This allows the vehicle ECU to determine the current flow in and out of the battery. It is important that you only connect any ancillary equipment to the cable side of this shunt and not to the battery side. However some DC to DC chargers specify you connect to the battery side of the shunt. Please refer back to the instructions with your particular unit.

What was going on?

Well basically the negative side of the circuit was getting a bit warm and the lead from the alternator was running at virtually it’s maximum rating. What you have to remember is that the vehicles electrical system is really designed down to a price and to do just the job of keeping the vehicle running. As soon as you start to ask a bit more of it you are stressing some elements and you have to consider all aspects and upgrade parts sometimes.

Conclusion

Adding an additional earth strap from the alternator mount directly to the chassis side of the shunt on the negative post of the engine battery and upgrading the alternator positive cable made a big difference and there is no longer any smell after a couple of hours of charging from the engine. Apparently starting the diesel engine has been improved with the report: “it seems to turn over a lot faster when starting” so maybe there was an underlying issue with engine earthing somewhere?

My two cent’s….

  • Don’t use the vehicle chassis as a neutral return path for any additional equipment you install. Modern vehicles are not so much welded as bonded together and some have aluminium or plastic body panels. Additionally even the steel they are made from is not as good a conductor of electricity as copper. Leave the vehicle electrics to the vehicle body and install your own neutrals.
  • Don’t ‘ground’ the leisure battery to the vehicle body. Keep the leisure battery circuits isolated from the vehicle body. Run a suitably sized neutral cable directly from the leisure battery to the vehicle battery.
  • Don’t use leisure battery terminals as a place to connect everything. Use a proper terminal bus bar block for live and neutral connections. The only connection on your battery terminal should be the main conductor going to either a second battery or a bus bar terminal block. The only exception to this is for battery monitors!
  • Don’t assume the vehicle electrics are up to the job. Most vehicle electrics do the job they were designed to do and not much more. As soon as you start asking the alternator to charge another one or two 100Ah batteries you are ‘stressing the system’ to a greater or lesser extent. Some big 4 x 4’s can handle this, some smaller vans might not be able to. Consider what you are installing and think about how the vehicle will handle this and look to see if anything needs upgrading.
  • Know what cable terminations to use and where. Also don’t cheap out on the correct terminal installation tool. If you are building or converting a camper van is it worth saving £25 on a proper ratchet crimp tool?

Don’t watch someone on YouTube do something and assume that if you do it exactly the same way it’s going to be right. It’s interesting on how many times people make a video on wiring or installing equipment and follow it up with “if you want to know more go and watch so and so’s video about it. He produces really good videos how to do this” Just because someone produces really good videos doesn’t mean the videos show how to do something correctly. It’s only how they did it, not an installation bible. You have to do your own research and learn to sort out the good guides from the bad.

I have watched an awful lot of YouTube motorhome refits, camper van, step van and bus conversions etc and a lot of the electrical installation – especially on the 12 volt side is poor in my opinion. I’m not an expert however and I’ll only ever say how I’d so something and the rational behind why I’d do it that way.

Just throwing this out there to see if there is any interest….. I was thinking about doing either a small forum on the blog or a Q & A page as a resource for some of the electrical ramblings. Would that be of interest/use to anyone? I do know that quite a few of the electrical drawings I have done have been downloaded and again wondered if specific drawings for equipment would be useful. Let me know in the comments below.

For Anyone Restoring A Vintage Caravan…

04 Thursday Jul 2019

Posted by in Caravan Electrics, Caravan Restoration, General, Modifications, Technical

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A short while ago two people contacted me separately asking if I had any information relating to rewiring restoration caravans so that they could plug into a modern 13 pin electrics tow car and take advantage of leisure battery charging and run a modern fridge or coolbox.

This was followed up be someone asking me how they could upgrade a late 1970’s caravan and still incorporate and use the “CAR-VAN” switch to change between using the leisure battery or vehicle battery.

Wiring diagram showing how to wire a vintage caravan to modern tow vehicle electrics

I came up with a couple of drawings that covered the basics to show how they could be upgraded to modern tow vehicles. The one above is a basic ‘front end’ from 13 pin plug back to a fuse block for the road lights and a habitation relay.

The drawing below add in the option of a “CAR-VAN” switch (sometimes labeled as CAR-CARAVAN) which uses the same 40 Amp relay as the habitation relay rather than a chunky high amp switch found in some models. However installing a CAR-VAN switch does have limitations… for example you could not install an inverter.

Wiring diagram showing how to wire a vintage caravan to modern tow vehicle electrics with the traditional CAR-VAN switch

If you want to download these drawings (or any others I have done recently) they are now in PDF format sized A3 and can all be found on the “Electrical Drawings” sub menu below “Document Library“. I kept getting emails asking where such and such a drawing was, so I decided to put them all into one place.

I don’t normally do electrical drawings for specific projects (unless being paid), however if you have something that you think might be of interest to a wider audience drop me an email.

Is A Euro 6 Engine Killing Your Leisure Battery?…

21 Friday Jul 2017

Posted by in Accessories, Amarok, Caravan Electrical Fault Finding, Caravan Electrics, Electrical, Maintenance, Modifications, Off Grid, Technical, tow vehicle, VW Amarok

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OK… so that title was a bit dramatic! However here’s the thing… I don’t think everything is peachy with Euro 6 engines and charging leisure batteries.

If you are a regular reader, you know I have recently installed one of Sterling Power’s Wildside units (and so far I’m super happy with it!) but I did get an email from someone who had read all my postings about it and asked me if it might cure his problem. Here’s the gist of his email….

Note: I have edited this down a bit…. and withheld the name of the person and vehicle.

“I have recently changed my car to a new 2017 xxxxxxxxxxxx and after several trips with it, on arriving home there is never enough charge in the motor mover to manoeuvre our caravan up our drive (which is on an incline) and park the caravan round the back of the garage. I have to plug the caravan in overnight before I can use the mover.

This only seems to have started happening since we changed to the xxxxxxxxxx. I had the caravan’s battery tested at two garages and they said it is OK and it is only 2 years old. The local caravan service man said he could not find anything wrong with the motor mover.

As we are on mains at the caravan sites we visit for a few days the caravan battery should be fully charged.

Can you help?”

This did have me stumped for a bit. Battery tested OK, no issues with the mover, so what was going on?

While doing some of the prep work for writing about my installation of the Wildside unit, I had spent a few days prodding about our VW Amarok with a multimeter and making a few notes about voltages etc. One thing that I did cotton on to was the cyclic way the vehicles ECU seemed to turn off the alternator…. well I should really say put the alternator into “idle” mode. Now with the caravan attached (pre Wildside unit install) I did notice that  at the start it seemed to take longer for the vehicle’s alternator to go into idle mode but also it seemed to stay in idle for a lot longer and I was in the process of trying to work out why as initially I’d have thought it would have been less as it was running the fridge and charging the leisure battery.

A picture is worth… you know the rest. Here’s one of my excellent drawings!

Euro 6 Problem 01

Right, here we go… The drawing shows a caravan plugged into a tow vehicle that has the engine-turned off. Pin 9 is live as it should be, and the habitation relay in the caravan is effectively off allowing the caravan’s leisure battery to connect and power the caravan’s internal 12 volt systems. As the vehicle engine is off, there is no power on Pin 10 the fridge circuit, as this is controlled by the vehicle’s ECU.

Really this could be any vehicle with any engine. Now let’s have a look at what happens with the engine running…

Euro 6 Problem 02

Pin 10 is live, turned on by the vehicles ECU and this powers the caravans fridge. It also operates the caravan’s habitation relay which now disconnects the leisure battery from the caravan’s 12 volt systems and connects it to Pin 10 so that the vehicle can start to charge it.

Again, this could be any vehicle with any engine. This is how our Land Rover Freelander works with our caravan. All straight forward.

Now lets look at what happens when the Euro 6 engine puts the alternator into “idle” (or Eco mode etc.)

Euro 6 Problem 03

This is where it starts to get interesting. I have taken a few liberties here and made a few assumptions. I have shown the vehicle’s alternator disconnected. In practice the ECU doesn’t disconnect the alternator, it will reduce the field voltage and hence the output, not really disconnecting it but reducing the output to a negligible amount.

The ECU will also monitor the vehicle’s battery voltage and continue to allow the vehicles general electrical system to drain the battery to somewhere around 75% charge (this may be a bit of an arbitrary figure) The ECU will then turn on (or up) the alternators output to recharge the vehicle’s battery to about 80%. Why 80% well it needs the remaining 20% ‘free capacity’ so that when you brake, the excess energy of engine braking (regen) can be dissipated into the vehicle battery. Remember that on a Euro 6 engine the alternator is capable of generating round about 2Kw.

Now at this point it dawned on me that something could be happening here, but the idea was a bit ridiculous…. guys with far more agile grey cells than mine must have worked this out and I dismissed the idea. I must have missed a trick somewhere.

I did a bit more checking. I was using two 17Ah sealed lead acid batteries as my “leisure” battery simply because it was quicker to charge or discharge them than a 120Ah battery. For a fridge load I was using 3 x 50 watt light bulbs and it was all jury rigged to a 13 pin plug so I could just plug it in to either the Freelander or the Amarok to make comparisons. I was using a trusty old AVO 8 meter, a couple of digital multimeters and a clamp meter to measure current so really the whole set up was super sketchy for anything that I could write about. I thought that I must have been missing something somewhere and I actually kind of put it to the back of my mind. I just got on with installing the Wildside unit and writing it up.

“DING” You have mail……

I received an email from Charles Sterling with some very interesting information. During testing he had come across exactly the same issue I was pondering over but had put off further testing. I guess by now you have worked it out. Quite simply you can get current flow in the opposite direction… from caravan leisure battery to vehicle battery. In testing Charles had measured a current of around 6 Amps.

It dawned on me that maybe during my initial testing with my jury rigged set up I hadn’t missed something and the readings I had seen were correct. Both Charles and I quite separately had (in my case ‘stumbled’) on a potential issue with Euro 6 engines and caravans.

Back to the original email earlier. It now made sense. The sender of the email was setting off from their campsite to travel home with a fully charged battery (being on EHU while they were on site) and during the course of the drive home, the vehicles ECU was actually reducing the fully charged leisure battery down to 80% charge as it actually thought that the ‘vehicle’ battery was at 100% charge. Hence when he arrived home, the caravan’s leisure battery didn’t have enough charge to run the motor mover long enough to put the caravan away.

So what does this mean in practice?

Well effectively (give or take a bit of loss due to cabling) the caravan’s leisure battery will only get charged to about 80%. You can now think of the vehicle battery and caravan leisure battery as being one battery bank because that is how the vehicle sees it. If the leisure battery is fully charged its voltage will be higher than the vehicle battery so the vehicle will turn off (or down) the alternator so that the vehicles electrical system can drain it to about 75% ready for accepting the excess energy from regen braking. The caravan’s fridge helps the vehicle by draining the battery bank that bit quicker.

This also answers another question. While I was testing, sometimes I’d plug-in my jury rigged setup and if my two little 17Ah batteries were fully charged I’d get a low current drain indicated on my clamp meter. I’d dismissed this to a certain extent, but now I realise that as my two 17Ah batteries were fully charged and the vehicle battery would be at about 80% charge, there would be enough of a voltage difference for a short while, that the two 17Ah batteries would try to equalise with the vehicle battery by recharging it slightly..

Whats the answer?

Well thankfully I solved my problem when I installed the Wildside unit a few weeks ago.

Finally…

If you have had any electrical issues with a Euro 6 engine and towing please drop a comment below. I’ll try to help.

As an aside, I am trying to arrange attending a tow bar installers electrical course with a couple of the OEM electrical equipment manufacturers and one of the approved bodies so I can hopefully increase my knowledge base and widen the number of vehicles I can cover. It’s a bit up-in-the-air at the moment as it would appear its going to cost a small fortune! (Sponsorship deals gratefully received!)

Getting All Charged Up – Update

02 Sunday Jul 2017

Posted by in Accessories, Caravan Electrics, Electrical, Off Grid, Product Review, Projects, Reviews, Technical, Towing, VW Amarok

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The best laid plans….

We had originally intended to spend a week down at Glastonbury which would have meant the 5 hour drive down would have been an excellent test for the Sterling Power Wildside unit’s first outing. However we had to cancel the trip literally the day before we were due to set off. In the few days between installing the Wildside unit and our planned trip to Glastonbury I had been exchanging emails and phone calls with Charles Sterling talking about some of the aspects of the Wildside unit and the direction that caravan electrics was heading in.

Continue reading →

Getting All Charged Up – Part 3 “The Install”…

30 Tuesday May 2017

Posted by in Accessories, Boondocking, Caravan Electrical Fault Finding, Caravan Electrics, Caravan Fault Finding, Electrical, General, Modifications, Off Grid, Technical

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There has been a bit of a delay since Part 1 and Part 2 due to Sue having a fall and breaking her arm in three places. This required over three hours of surgery to install enough metalwork and screws to keep a blacksmith happy followed up by a lot of trips back and forth to the hospital. However, on with the install of the Sterling Power Wildside unit. I think that this will be the first ever install of a unit in a caravan.

I printed out copies of the wiring diagrams and loaded up the Amarok with everything  I’d need and set off for the storage site. Arriving at the caravan everything was cleared out to give me some space to work.

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I’d planned to install the unit somewhere close to the Sargent control box as all the connections I’d need could be found here and it was close to the fuse box that connected the lead from the 13 pin plug to the caravan services.

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The fuse connection point for the lead from the 13 pin plug is in our caravan, located right at the front next to the centre chest of draws against the gas locker wall.

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Before starting, I did a quick voltage check on the leisure battery…. 12.81 volts, which isn’t too shabby as we don’t have a solar panel and it had been February 25th when I left the Caravan show at the NEC and the battery was last charged up. Which was   about 13 weeks earlier.

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To gain access to the wiring going into the Sargent unit, I removed the 4 screws holding the top cover on and the lid simply lifted off revealing all the connections and as a bonus, service loops in the cable. This meant it should be possible to install the wild side unit without having to do any cable splicing. I did debate at this stage if it would be possible to install the Wildside unit inside the Sargent box… but I decided as I didn’t know the heat gain of the Wildside unit, it might be prudent not to attempt it.

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The cables inside the Sargent box are basically separated into two looms. One 12 volt and the other 230 volt which keeps things easy and neat. Also the back of the circuit board within the Sargent unit was printed with each of the plug numbers, so doing all the planning paid off as I could simply find the plug number from my diagram and locate the correct cable easily.

I decided I was going to do a pre-install and connect the Wildside unit up and do a few tests, then once I was happy I’d go ahead and do a full more permanent installation.

It was simply now a matter of finding the plug I needed, unplugging it, locating the correct wire, cutting it and terminating it in the Wildside unit.

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I cut the cables about 4 inches away from the circuit board plug. This would give me plenty of length to crimp on a sleeve connector and heat shrink if I needed to remove the Wildside unit. As a backup I have also ordered some replacement pin inserts for the plugs so I could always re-terminate directly into the plug.

The next connections would be the incoming feed from the vehicle. 4 cables, two neutral and one positive fridge supply from pin 10 and one positive charging supply from pin 9.  These arrive from the 13 pin plug via the fuse box mounted on the front wall through two 20 amp fuses and to the Sergeant unit. I had trouble identifying the cables as the colours were not as indicated in the manufacturers drawings. So to double check I removed the fuse box to gain access to the 13 core cable where it terminates.

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It was easy enough now to trace the correct cables and confirm with my multimeter. So all the connections now made, albeit temporary, I could install the 20 Amp main battery fuse and make sure the Wildside unit powered up OK.

Don’t worry about the brass bolt holding together the three cables, it was so I could easily get a clamp meter on the cables to take current readings.

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It started up without any problems and so I could connect up the 13 pin plug to the Amarok and start the engine and take a few measurements.

I checked the vehicles voltage and it was sat at 14.5 with run/stop disabled and the engine ticking over. OK how come I had a voltage of 14.5 volts in the vehicle with a Euro 6 engine ticking over? Well the Wildside unit basically makes the vehicle’s ECU think that the vehicle battery requires charging (remember an Euro 6 engine cranking battery will only ever be charged to 80% of its capacity so that regen will always work).

The first reading I checked was the leisure battery incoming link. I had a reading of 9.96 volts and a current of 8.8 amps. That was quite a big voltage drop.

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I moved on to test the incoming fridge circuit. This was showing 9.99 volts and a current of 13.3 amps. I had a big voltage drop somewhere. I checked the voltage at the point the 13 core cable terminates and got a reading of 12.75 volts. somewhere between the incoming cable and the termination on the Wildside unit I was getting a  big voltage drop.

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Continuing with taking some readings, I checked the fridge output and it was stable at 14.35 volts, 9.9 amps.

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A problem with the fridge…

On the original caravan wiring diagram it showed the fridge heating element connected with just two wires and on the face of it this looked simple enough. However when I first connected the fridge and powered up, the fridge came up with error code 10 – no power. There was definitely a supply voltage there and it was indicating a current draw of just under 10 amps. I wondered if the voltage detect circuit was polarity sensitive so swiped the connections round and this cleared the error code. So double check the polarity of the connection if you get an error code 10 don’t assume there is a connection fault.

Thinking cap on…

I decided to stop at this point. Unless I could eliminate that volt drop between the incoming cable and the Wildside unit it was pointless taking any further readings.

The next thing to do would be to eliminate the existing wiring for the leisure battery charging circuit and fridge circuit between where the incoming cable from the 13 pin plug terminated and the Wildside unit. I decided to replace the existing caravan wiring with some 2.5mm² cable.

First job was to terminate all the previously terminated cables on the Wildside unit correctly with the correct size ferrule crimped on. When ever you terminate a stranded cable in  a terminal block that compresses the wire, you should first crimp a ferrule on to the cable to ensure a secure connection.

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Next I installed the four new 2.5mm² cables from the 13 core cable to the Wildside unit. I opted to use straight through sleeve crimp connectors to join to the cable coming from the 13 pin plug. I kept the length as short a possible – about 900mm, which resulted in not the best cable route option but I wanted to minimise voltage drop. (remember, the more current you draw through a cable and the longer the cable the bigger the voltage drop!)

All that done, and the correct terminal block installed for the battery positive lead rather than my brass bolt, I powered up everything and hooked up the Amarok and started the engine once again. With the engine running the vehicle was showing 14.7 volts and I was now getting 14.1 volts on the incoming charing circuit with a current draw of 8.2 amps. Note: the clamp meter in the picture is actually showing the charging current for the leisure battery… 5.0 amps.

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Checking the incoming fridge feed I was reading 14.2 volts and a current of 8.6 amps. Which was a vast improvement over my previous readings. (Note: the clamp meter in the picture below is still showing the battery charging current)

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The battery charging voltage was showing 15.01 and 4.8 amps which meant I was at least charing the battery with just the engine on idle.

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Doing a little maths – I was pulling 8.2 Amps via the leisure battery charging circuit and 8.6 Amps via the fridge circuit giving a total of 16.8 Amps. I was supplying 9.9 Amps to the fridge and 5.0 Amps to the battery. A total of 14.9 Amps. The difference would be due to the losses due to stepping up the voltage being supplied by the vehicle to the output voltages of the Wildside unit. In terms of watts – the vehicle was supplying 237.74 watts and the wild side units was outputting 224.49 watts.

This did make me think. As the fridge was now consuming 149.49 watts (its rated at 150 watts) so it in theory should be at it’s max efficiency… did it need to be on all the time? Could the fridge be switched on a duty cycle of say…on for 75% and off for 25%? This would then increase the ability to put more back into the leisure battery, especially useful on short runs.

Speaking to Charles Sterling, I know this unit has been rated on the conservative side and in theory 20 amps can be pulled from each circuit. This would give around 560 watts of power… and in theory about 400 watts available for charging the leisure battery. Will that damage your vehicle? Well as most Euro 6 engines are fitted with 2Kw alternators, there is still plenty of power available.

Finishing up

It was now a matter of tidying up my mess and installing some cable ‘p’ clips to secure everything to the floor. The two sleeves on the cables that come from the 13 core cable are there so I can identify each circuit. Red for leisure battery charging and blue for fridge circuit.

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The yellow fuse you can see is the leisure battery fuse. It’s rated at 20 amps and is in circuit between the leisure battery and the caravan services, so pull that fuse and the caravan will be isolated from the 12 volt system. I’ll probably replace that with a circuit breaker in the near future.

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A couple of things I thought about while doing this install.

The Sargent control box is a lot of wasted space. I recon that it should have been shrunk down to ¼ of it’s current size and probably relocated to somewhere else… maybe under the draw unit at the front of the caravan.

The incoming fuse connection panel too seemed a little flimsy. All it consisted of was a circuit board with multi plug connectors on one side and spade connection soldered on the other for the blades of the fuses to slide into. Some of the soldering looked ‘dry’ and I wondered if this was causing some of the volt drop I was experiencing… that coupled with the multi-plug connections in the loom. I know it makes the build of the caravan easier on a production line and you only need semi skilled labour to install but hey sometimes things like this matter.

Its obvious that caravan wiring is done down to a cost and the minimum standard required. I would have liked to seen some slightly heavier gauge cable for some of the connections. It amazed me that the leads that connect to the battery are 6mm² but drop down to 2.5mm² once outside the battery box and the connection between the two is just a simple male/female spade connection.

The other thing that struck me was how inefficiently the plumbing was done. I’d never really looked at it before, but casting my eye over it I think I could have laid it out a bit better and saved three push-fit connectors.

Who’s this unit designed for?

Well anyone really that has a Euro 6 engine in their tow vehicle or motorhome (if you have a motorhome you need to look at the BB1230 which is a step up again from this) and cares about maintaining their leisure battery.

If you have a motor mover fitted and use it to get your caravan out from its parking spot before you set off and then find sometimes you don’t have quite enough power to position your caravan on your pitch when you arrive or the reverse… your motor mover always seems to run out of steam trying to put your caravan back in its storage area when you return home, the Wildside unit should make sure you always have a fully charged battery and I’m my opinion is something that should be classed as an essential item.

From a lot of emails I have received it would seem that generally people with motor movers seem to be changing their batteries more frequently. A lot of the time when the motor mover stope working or works erratically the advice from the motor mover manufacturer is “you need a new battery” or” its a problem with your battery”. I”m going to throw this out there… I think it may be down to the batteries never really getting a proper charge and sulphating, radically shortening their life.

Alternatively if you do a lot of “Off Grid” (Boon-docking) camping, this will make sure you maximise the charge in your leisure battery to allow you to get the most from it. Especially if you have a Euro 6 engine.

How easy is it to install?

Planning is the key and a modicum of skill in being able to trace cables and terminate correctly. However a lot is going to depend on your caravan, how it is connected and the quality of the original installation. For me it was quite straight forward but the location of the existing components made it easy. Depending on your particular caravan you may end up having to run some additional cabling. Whatever you do, do not cheap-out on cable termination! Buy the right terminals and a good ratchet style crimp tool and make sure any cable you install is a good quality brand of the correct gauge.

Were there any issues?

Nope, it worked straight out of the box.

What next?

Road test! In a few weeks we are travelling down to Glastonbury which is between a 5 and 6 hour tow and I’ll be taking readings during the trip to see how the battery is being charged and the fridge temp. Just for the pure fun of it….. I’m going to try to make ice cubes in the freezer so we have ice for our drinks when we arrive! I’ll let you know how I get on.

Looking forward.

The biggest problem really is the fridge. A three way absorption fridge is probably the single most inefficient way of chilling anything. Whether its powered from 12 volts, 230 volts or gas. Its far more efficient to use a compressor fridge.

Now a 230 volt compressor fridge is relatively cheap when compared to a three way absorption fridge, great for when you are on hook up, but now imagine being able to run it via an inverter while you are driving or off grid from your battery. As they only run short periods and take less power to run. Coupled with the fact they don’t run continuously like an absorption fridge. It would be possible to do away with a 3 way absorption fridge completely.  As we now have a sensible way of charging batteries, and given the fact the price of modern lithium battery technology is dropping all the time I don’t think technically we are far off making the transition. Its just down to the caravan manufactures…. so don’t hold your breath.

Contact:

Sterling Power

Stuff I used:

You can find links to all the crimp terminations and tools that I used in the Caravan Chronicles Shop

 

NEC Show Roundup – it’s all technical…

28 Tuesday Feb 2017

Posted by in Caravan Electrics, Electrical, General, Maintenance, Modifications, Technical, tow vehicle, VW Amarok

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This is really a follow-up to my previous post – Smart Alternators: how they affect Caravans and Motorhomes….

While at the NEC show one of my big tasks was to get a number of technical questions answered by the industry players. One of my first stops was to Westfalia and to meet up with Rick Sykes and his colleague on the Westfalia stand. Rick is the national training manager for Westfalia and I was able to get answers to a number of questions that you have asked me and I’d not been able to answer fully. Continue reading →

Little Things….

04 Sunday Dec 2016

Posted by in Accessories, Caravan Electrics, Electrical, Maintenance, Modifications, Technical

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One of the little things that has been on my “must do something about that” list for a while is to address the problem we have with not enough places to plug things in and charge them. When we are in the caravan in the evening the front looks like a tech gadget table top sale… Macbook Pro, WiFi router/MiFi device, two iPhones, camera battery chargers, Fitbit charger and all these needed plugging in. The 4 way surge protected power strip I put there just wasn’t cutting it any more.

It was time to do something about it. A couple of years ago Swift supplied a kit to modify the drop down TV system that was installed in a range of their caravans. Our caravan already had the upgrade, however they did supply a new piece of wood to replace the installed piece as some of the holes had moved when they upgraded the latches. Always wanting to repurpose things I thought that this could be the basis of an upgrade… not to the TV drop down but to the rear of the draw unit. I wanted to install USB charging ports but still required a couple of 240 volt sockets and a brief search on Amazon I came across what I needed. The other thing I wanted was a couple of 12 volt sockets so that I could use our 12 volt plug-in USB chargers if we were pitched off grid.

To The Bat Cave…

The build was fairly simple. I had already converted the draw top from a slide and swing open operation to a pull out so the addition was straight forward.

The top being assembles in the workshop

The top being assembled in the workshop

It was a simple matter of cutting out the two rectangular holes for the 240 volt face plates and opening up the two existing holes intended for the new latches to the right size for the 12 volt sockets. I did intend to use the same electrical fittings as are already installed in the caravan but pricing everything up it came out at nearly four times the cost of what I eventually used here.

The two 240 volt sockets are wired with 2.5mm multi-strand cable and have slim line back boxes to protect them and the 12 volt cabling is all done with crimp connections and protected with heat shrink tubing.

The whole project including installation only took me a couple of hours and made me wonder why I’d been putting it off for so long!

I didn’t want to fasten anything to the structure of the caravan so the piece seems to ‘float’ above the front sill. The wiring was all pre done in the workshop and was easy to connect up to the caravan services as we had a 240 volt and 12 volt outlets nearby in the base of the draw unit.

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Plenty of room even with the blind down.

The upgrade now gives me 3 x 240 volt sockets and 6 x USB charging points plus 2 x 12 volt sockets. The space under the sockets can be used to tidy any excess charging cable away while in use.

Shopping...

Use the following bits from Amazon…

Knightsbridge SFAV7USB4MB 13 A 1G Screwless Switched Socket with 5 V DC 5.1 A Quad USB Charger with Chrome Rocker – Matt Black

Knightsbridge SF9902MB 13 A 2-Gang Screwless Switch Socket with Dual USB Charger – Matt Black with Chrome Rocker

The back boxes came from B & Q and the 12 volt sockets came from Go Outdoors caravanning section.

Caravan Chronicles Shopping…

21 Thursday Jan 2016

Posted by in Accessories, Blog updates, Caravan Chronicles Shopping, Caravan Electrics, Help Guides, Projects, Technical

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I receive a lot of emails asking where people can buy some of the tools – especially some of the crimp tools and terminations I use in my posts and articles. In the past I have just emailed people back with the details and maybe links. However my last post about cable termination brought on a rather large amount of requests. So I have decided that I will include links to the products on Amazon. So from now on you will see a section at the bottom of any posts called….

Caravan Chronicles Shopping...

Any specific items used will be listed, and by clicking on the link to the item you will be taken to the Amazon store page. If you do decide to purchase anything, it will be from Amazon (or their associates) and delivered by them. It’s just like buying from Amazon directly.

The price you pay is exactly the same as it would be by going directly to Amazon. All I receive is a few pennies from each sale that will help towards keeping the wheels of Caravan Chronicles turning.

I have also created a shopping page that lists the products under a link to the original article. There aren’t any photos, just descriptions to keep the page neat and quick to load. If you want to go back to the article, just click on its title.

I hope you don’t mind me doing this, but it will save you having to email me asking where to get things from and save me a bit of time in replying to everyone.

Cheers

Simon

Cable Termination 101…

03 Sunday Jan 2016

Posted by in Caravan Electrical Fault Finding, Caravan Electrics, Electrical, Help Guides, Maintenance, Modifications, Technical, Tips

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As it’s now the ‘off season’ for a lot of caravaners and thoughts turn to sorting out those problems that we put up with on the last couple off trips, I thought I’d look at cable terminations. One of the problems that I’m asked about revolves around cable termination in trailer sockets and plugs. Like most things there is a right way and a wrong way of doing it and there is also the compromise.

So what’s the problem?

Well the problem is terminating a cable to a solid metal part. You will most likely see cables that are striped down to the copper conductors and the individual strands twisted together then inserted in a hole with a screw tightened down to hold the conductors. So whats the problem with this? When you tighten the screw it’s turning obviously and the end of the screw twists down on to the strands of cable, often breaking a few off and pushing quite a few out-of-the-way, usually in an average termination about a quarter of the strands are not held under the screw tip. The 2.5mm square cable you thought would reduce volt drop for the battery charging circuit is now reduced to something less and its current carrying capacity is reduced. Is there a solution?

The obvious one would be to solder the ends of the cable to stop this happening and it’s a great solution, but is does have drawbacks. When you solder the end of a flexible cable the point where the solder stops becomes a weak point and is susceptible to vibration and flexing stress and the thin copper strands transition from being flexible to a solid mass. This is why in aviation, marine and military applications soldering is not usually permitted.

The correct way that flexible conductors should be terminated is by crimping on a “boot lace ferrule”. These are simple brass tubes, sometimes nickel-plated that are slid over the untwisted strands of the conductor and crimped tightly. Some ferrules are just small tubes or ‘U’ shaped section machine crimped and some have a plastic insulator to help isolate the conductor when several are installed in close proximity.

Here’s a simple step by step guide to crimping and terminating a 13 pin trailer socket. It could equally apply to a trailer plug.

For the photos I used a spare socket and short length of standard multi core cable. I have links to all the items, including tools used in the article in “Caravan Chronicles Shopping” at the end.

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The tools required are a sharp knife, cable strippers, screw driver, ferrule crimps and the ferrules. (tip: make sure your screw driver is a ‘terminal driver’ with flat parallel faces and if fits snugly into the screw head. As the screws are brass, it’s easy to damage the head using the wrong screwdriver)

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The first step is to trip back the outer cover for the cable. Strip back enough so that the individual cables are long enough to trim to length:

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The next thing to check is have you got the right end of the cable? The cable manufacturers lay the individual conductors in a specific pattern so that when stripped, the pattern of colours is in the right order for the end you are terminating. If you have the incorrect end of the cable you will have to cross all the colours over each other to install them correctly in the plug (or socket) As you can see, this is the wrong end for a socket:

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Ok, I’ve stripped the other end and you can see the colours are in the right ‘order’ for terminating a socket:

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Next we need to measure the difference in termination length between the four centre line and the 9 outer pins… here it’s about 8 mm:

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Measuring the back waterproofing cover I know the outer jacket needs to be a maximum of 45 mm from the 9 outer pins and the 4 inner pins need to be trimmed back to 37mm:

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Now the cable is cut to the right length so there should be no short or long cables causing problems when assembling the socket:

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Strip back the individual cables so the exposed conductors are the same length as the ferrules:

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Slide the correct diameter ferrule on to the exposed conductors:

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Crimp into place:

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The crimp tool is set so that it will only apply the correct pressure to compress the exposed conductors the required amount. Squeeze the handles and the four jaws close on the ferrule and compress it, continue squeezing and once the jaws have attained the right pressure the ratchet mechanism in the handle releases.

If you look at the picture below you will also see that the crimp tool also presses several ridges into the tube, this is to increase the mechanical grip on the conductors and help stop the tube distorting under the pressure of the terminal screw tip:

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Continue until you have all the cables completed:

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One last check… look for stray strands and anything that doesn’t look as though its crimped correctly… give them the ‘tug’ test if in doubt.

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I always like to back off the screws so the ends are just visible in the holes:

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The next thing you might need to do is correct the length of the ferrule. I have used standard length ferrules and as the holes in the socket terminals are not as deep, I had to trim off the excess. The ridges pressed into the ferrule body help gauge how much to trim off. In this case I only had to snip off to the first indent:

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Once trimmed to length, it’s a simple matter of following the colour coding and inserting each cable and tightening the screw. I always start with the four pins in the middle:

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Once all the cables are terminated, have a good look to see if all the screws are tight, and of course check the colours are in the right place!

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Because the cable was trimmed to the right length before we started there are no loops, so the cover can slide on neatly:

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There we go, a finished socket all ready to mount onto the bracket:

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To terminate the socket  from start to finish and while Sue (thanks `Sue) took all the photos took no more than 25 minutes. Ok it was on a bench and doing outside at the back of a vehicle will take a bit longer, but it’s not that difficult to get a professional result.

The ‘Compromise’

Right back at the start I said there was a compromise – soldering. It’s not difficult to do and achieve and end up with a professional result.

Practice makes perfect and its worth having a go on a scrap length of cable first.

Here’s a few of my tips for successful soldering:

Don’t apply too much heat to cause the insulation to melt (turning down the temperature of the soldering iron or reducing the contact time between the soldering iron and cable helps)

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Don’t try to melt solder onto the tip of the iron and run it in to the cable you will burn off the flux too fast… instead touch the solder onto the hot strands of the conductor. Capillary action will pull solder into the strand bundle.

Don’t allow too much solder to be drawn in. You are looking for just enough to still be able to make the outlines of the strands of cable, not a big ‘blob’ of solder on the end.

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The solder should look shiny not dull. If it’s dull, the solder cooled too soon as the conductors were not hot enough, this is commonly known as a ‘dry joint’ the solder sits on the surface of the copper.

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Avoid breathing in the fumes given off from the flux and the solder. Solder is an alloy of tin and lead… and the flux is pretty nasty too. ( I have an old computer cooling fan that I use to blow the fumes away if I’m doing a lot of soldering).

If you have made the soldered cables too long, you can always trim them back to the correct length. Soldering all the conductors in a caravan cable like this usually takes me no more than five minutes from start to finish.

A few practice runs will soon get you producing good results.

Finally to finish off, I usually give the finished connections a spray of ‘liquid plastic’. It comes in an aerosol can and when sprayed on form a thin plastic coating over everything. You can usually find it in motorbike and automotive shops for waterproofing electrics and HT leads.

It easy to get a good professional result, and I still can’t understand why some tow bar fitting companies don’t either crimp or solder their connections. They usually do when it comes to connecting the other end of the cable to the vehicle. The cynic in me wonders if they are hoping for repeat custom when sockets or plugs start to have problems in the future.

Caravan Chronicles Shopping...

I have been asked where you can purchase some of the products featured above. Here are the links to the products in the Amazon store. If you click on the links and purchase the items, a few pennies will go to helping the cost of running CaravanChronicles.com

Crimp Tool : Hsc8 6-4 Self-adjustable Ratcheting Square Ferrule Crimping Plier for 0.25-6.0mm² Wire Terminal

Wire Ferrules : 750x AWG18 AWG16 Wire Crimp Insulated Ferrule Pin Cord End Terminal

Soldering Iron : 50w Variable Temperature Adjustable Controlled Solder Station Iron Gun Soldering Kit Set

Solder : Solder with Cored Flux 100g 60/40 Tin Lead Resin 0.7mm

13 Pin Milenco Socket : MILENCO 13 Pin Socket Black Caravan / Motorhome / Trailer

13 Pin Milenco Plug : Milenco 13 Pin Plug

13 Core Cable (8 x 1.5mm + 5 x 2.5mm) ISO Approved : 13 Core Caravan Cable Sold per metre