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!
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…
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 9 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.)
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!)
Caravan Chronicles 
Please excuse the intrusion from the Dark Side! Ex Caravan owner now a Motorhomer. I wish I’d found this your blog some time ago. I run a couple of sites for Benimar Motorhomes and as a techie deal with all the electrical issues predominately. A number of members had fairly identical issues. So I set about investigating as you have. With her that must be obeyed driving my van, me in the back with a smattering of Avo 8 (love my Avos, you get a little parallax error when she drives over potholes🙄 ) Flukes etc, a motorcycle battery as the leisure battery and the fridge as was. After a little head scratching and delving into the integrated split charge relay in the CBE DS300. I came to exactly the same conclusion, the relay was in fact in parallel with vehicle battery. There is a blocking diode but this clearly wasn’t up to the job. Your circuit if you take it as one unit is after all the same as a motorhome, with the division removed. Since that point I’ve modified my unit and have been extolling the virtues of DC-DC chargers, although it’s very hard to get people to see the light! They ask the questions but do not necessarily like the answers! The additional benefits of DC-DC chargers of course is the higher charging rates and the fact you can charge almost any chemistry of battery correctly as you know.
I have to congratulate you on your fantastic blog. I have to say I’ve been avidly reading it and it just underlines all the eternal questions I get asked about inverters, batteries cabling etc etc.
Thanks for such a great read👍
Thanks Steve for the kind comments…. sometimes I think I’m just talking to myself.
Keep it up you’re doing a grand job Simon. It’s hard work and very time consuming and I for one appreciate that!
Just pleeeese don’t ask me ‘Can I xyz’ AGAIN!
Take care, Rgds Steve
Apologies for dragging up an old post. A poster on the Practical caravan forum was inquiring why his caravan battery was going flat and at the back of mind I could recall reading something about this issue on your blog.
When I last posted I had 2013 Shogun which we only had for 3 months before trading it in for a 2012 Jeep Grand Cherokee. However I have since traded in that Jeep for a 2017 Grand Cherokee, but at the time of fitting the towbar and electrics I opted not to have the feed for the fridge done, however it seems that the caravan battery could still be drained by the Smart alternator. Unfortunately due to personal issues, we have not been able to use the caravan for several months except a tow to the dealer and back in December.
As we are proposing to travel to France or Spain, we are now considering having the fridge connection done, but are unsure of the battery draining.
The cost of the Wildside is a lot more than we would like to pay and are now wondering if there is a lower cost work around? Any thoughts?
Hi
The simple fact is that with Euro 6 engines, especially with those fitted with regen braking option they will only ever charge the vehicle battery to 80%. Therefore any leisure battery in the caravan will also only ever be charged to 80%. Unless you opt for a WIldside unit or a 12 volt DC to DC charger which is simpler to install, then there are no real shortcuts.
The lower cost option would be to install a 10 amp DC to DC charger in the caravan. It would take longer to charge up your leisure battery, but would ensure that it was charged to 100%.
Thanks Simon. I think it will be best to wait and see until we have towed the caravan a few times. The caravan has an 100ah AGM battery and had E&P self levelling so essential that battery is working correctly on arrival at destination. Our first trips are within 40 miles of home.
Are you able to suggest a way that we may perhaps be able to monitor the battery or is it as simple and doing a check before setting off and on arrival at destination to see if battery has drained?
The best way is to keep an eye on the voltage using a multimeter. There are bluetooth monitors that pair to your phone, but they are quite expensive for what they are and I’ve looked at a couple and really could not recommend them.
Simon,
Can you point me to a 10 amp D.C. to D.C. charger? Apart from the 2 amp Optimate one, any I’ve found are in the 20 to 25 amp range which is too much for the 15 amp circuits in my Land Rover Freelander 2. Interestingly, the Sterling Wildside gets round this problem by utilising both the constant power and the switched power to provide the power to the unit. However, I seem to recall you saying that it was bad practice, or words to that effect, to use the switched power for charging.
Hi
Renology do a 20 Amp version that can be limited to 10 amps input via dip switches from memory… it was quite a while ago so you would need to check. I think a number of companies have products that allow input limits to be set.
Generally combining the two circuits (leisure battery charging and fridge power) is a bad idea… a low power input would mean the fridge essentially runs on the leisure battery to make up for any deficiencies in the supply from the vehicle. However, how Sterling Power have implemented it in their Wildside unit protects from overload in each circuit and from any possibility of the leisure battery powering the fridge…. unless that is what it was programmed to do. I’ve been running ours for a few years now and not had any issues.
Thanks, Simon. I’ll check out the Renogy one.
Hi,
Just discovered some of your reports while troubleshooting an issue – a great help, thanks.
Unfortunately I have not been able to resolve it, so any additional info would be appreciated.
I have a 2016 Kia Sportage (euro 6) with a 13pin socket for a caravan.
The live feed for the fridge (pin 10) has gone down.
The earth is fine, so have traced the wiring back from the car battery to the socket. I have found 2 fuses next to the battery and 2 more in the back of the car, all are ok.
I guess the next culprit would be a relay, but that is where I need some help. The only “relay” I can find is a Jaeger Voltage Control (321061) – is this it, and how should I test it (I get approx 73k ohms accross pins 30 & 31, while the other 2pins are open circuit with both 0 & 12 v applied to 30 & 31)
Hi Phil
The fridge feed (pin 10) is usually controlled via the vehicle’s ECU and turns on shortly after the engine is started. I have known this to take up to 10 minutes if the vehicle battery is low or starting to fail.
The Jaeger voltage monitoring unit as far as I know is usually in the battery charging circuit and is to prevent the main battery being depleted. https://www.erich-jaeger.com/en/products/321061
With most Jaeger kits there is usually three fuses near the battery, two 15 amp and one 1 amp. The two 15 amp are the fridge and leisure battery supply and the 1 amp is the voltage regulator circuit.
I think this is the kit that is installed on your vehicle… https://www.jaeger-poway.com/products/product-category/wire-harness-vehicle-specific/7p-12v-wire-harness-iso-1724-type-n-737499
If you look at the link above, you can download the installation instructions which might help. It does show there is a module that links into the vehicle CANBUS though and a piggy back fuse that is installed in the main vehicle fuse panel under the dash.
I don’t have the data sheet for the relay so I’m unable to give you much advice on how to test it.
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As a matter of interest how much heavier would a compressor fridge of the same dimensions be and can it also operate on gas?
The ones I have looked at so far are slightly lighter, have a higher insulation rating and a tad larger on the inside for the same external dimension traditional 3 way fridge I’ve not seen one that can operate on gas as well but there are some that can apparently as there are compressor fridge boxes that do.
Hi Simon,
After reading most of your posts I had already arrived at the conclusion that you are not biased and will tell it as it is.
Like Clive above I am not satisfied that things work but want to know why and how they work, that will be the professional engineer in me.
I will purchase and fit a wildside unit as soon as I can but at least I have a temporary workaround by adding additional load to the alternator by having the headlights on while towing.
Keep up the good work.
After reading most of the posts about this issue, I think a wildside unit is the best solution.
So when funds allow I will purchase and fit but until then it will be headlights on when towing.
Thank you for all the advice.
Steve, I have to say I’m biased as I got one (wildside unit) for free as part of being involved in the development and promotion.
That said, I do back the product 100% and will continue to promote it. Apart from the initial unit I received from Sterling, I have no ties to them nor am I paid by Sterling to continue to promote it. But I do…. because it works.
Been having exactly the same problem since last year with a new to us, 2014 Honda CRV.
No mention of a smart alternator in any documentation and a Witter tow bar and dedicated electrics fitted.
The fridge would work intermittently and the mover would sometimes struggle after a journey.
I thought it was a loose connection somewhere so took the opportunity to rewired the van from its original 12n and 12s to 13 pin cable and plug to match the car.
This is when I found you brilliant and informative site.
Just testing it this morning and much to my annoyance the fridge still only comes on sometimes, after a coffee and a read of your euro 6 article it got me thinking, went back out to car and van and started it up, still no fridge working, put a meter across the car battery terminals 12.49v with the engine running, I would have expected between 13.7 and 14.7, had my wife switch on the headlights and the voltage across the battery jumped to 14.7 a quick look at the fridge and it’s working, when the headlights are turned off the fridge turns off also.
So I now know that I too have a stupid smart alternator.
The solution for me is to either drive with the headlights permanent on or fit an aftermarket device.
Thank you for an brilliant and informative website.
I have a 2015 CRV. Although the Honda dealer said the alternator was not “smart” it is obvious to me that it is. I plugged in a cool-box and found that the fan speed increases on the overrun or braking and reduces when the throttle is activated. A mutimeter on the cigarette lighter socket will no doubt tell you the same. The solution is a clever box from sterling power or votronic . But do read the original article from Simon and the recent followup which details all the problems. The Euro 6 standard is obviously there to reduce emissions and reduce fuel consumption, unfortunately there was no consideration for people who tow modern caravans. Equally responsible are the manufacturers of the caravan electrical systems who appear not to have researched the subject.
As an aside check that the relay fitted to your model does not have a voltage activated relay fitted. When my towbar was fitted by a Honda dealer I enquired if they were of a modification kit (specified by Honda) which requires a change to an ignition sensed relay (again because of the “smart alternator”. They looked a bit shamefaced and had to start again!!
The solution is not cheap but very effective.
Cheers
I have just checked the installation instructions for my tow bar wiring and it has a voltage control module (relay) that is factory set to turn on, with the engine running, at a preset figure of 13.4v and off at 12.7v.
As my battery only gets to around 12.5 volts that’s why the fridge only works with an additional load on the battery.
Don’t know if a relay with a lower activation threshold is available or thinking of putting a couple of beefy diodes in the fridge and charging circuit so the car see’s the caravan as a load rather than an additional battery.
You would only need one on the fridge circuit as long as the habitation relay activated in the caravan. However… prudence says putting two (one in each circuit) would ensure you never have a reverse current flow from the caravan to the vehicle.
Steve ,
I will leave Simon to advise you BUT I can confirm that the original and Honda approved installation details specified a voltage controlled relay which were supplemented by a modification kit which specified an ignition controlled relay. I believe that this is a bodge as the CRV has an ECO mode which no doubt reduces the load on the alternator, and consequently the output of the alternator, ( understandably in the interests of reduced emissions). I am bound to say you should follow Simon’s advice and fit something like the Sterling product which he has mentioned. Diodes will cause a voltage drop over the lengthy wiring and negate the intention.
I know it is frustrating but we must be aware that the caravan industry does not have the resources to keep up with the modern car industry. Hence the problem.
Thankfully we have people such as Simon who has the intellect and ability to analyse these issues and resolve them when he can.
Please read his detailed blogs on this subject, which, (if you are as thick as me, take a while to sink in), then you will see that he has resolved an aftermarket solution to the problem for the benefit of all.
Wow, some kind words there Clive, many thanks.
I do agree that really diodes are a sticking plaster to a problem that the industry should address. You can’t really blame the vehicle makers, as at the end of the day they are actually providing the wherewithall to install a 13 pin towing socket.
My thoughts on the subject are that the caravan industry is at least 5 to 8 years behind vehicle technology. You could argue that maybe the OEM equipment manufacturers that supply the interface boxes could do more and quite easily solve the problem. However the issue for them is that they might not receive manufacturer approval for their products if they effectively bend the rules so that caravan work correctly when plugged in.
I think that the caravan manufacturers have to talk to their electrical system suppliers (Sargent in the case of Swift Group) and build in to the caravan a DC to DC charger that can allow the caravan to function correctly. I also think that they should now say to the electrical equipment suppliers that they have to take into account customers want options for different battery technology. (I had an email a few days ago from someone that has just trashed £2000 of Lithium batteries as the dealer selling them a brand new caravan assured them that the inbuilt charger would be fine with that battery chemistry)
I also think that the old caravan fridge technology should be scrapped and 12 volt compressor fridges installed as standard fr more efficient and you don’t have to cut to mahoosive holes in the side of the caravan. It would also open up the options for placing fridges in different locations within the caravan and not be tied to an outside wall.
Sometimes i feel as though I’m shouting through a megaphone in the carpark…. and those inside just continue dunking their biscuits and muttering “he’ll go away in a minute” and carry on agreeing to carry on in exactly the same way.
Simon,
You are doing a bloody good job, The fact is that they are starting to listen to you. Please maintain your independence and sensible advice. I believe they are starting to recognise social media and the reliance people have in it versus advertising. Don’t be concerned about a free lunch, just tell it as it is. Please carry on making us aware of products we could benefit from, but make it clear if you are profiting from it.
I’m bound to say you should stop being concerned about your readers. Some of them will not have a clue about what you are talking about and just require resolution. Others, probably people like me will want the inns and out of a cats **s. A difficult balance to achieve. You have achieved it so far .
You can publish this if you wish. I will leave it to you
Once again
Thanks
Simon
I have a euro6 2017 ducato 130 2.3 multijet motor home. I don’t think it has a smart alternator. I tow a vw up 2018 1.0 (not a caravan) on an A frame. It has 13pin plugs at both vehicles/ trailer. I believe pin 10 is wired to the car/ trailer battery. The car uses electronic trigers to apply the brakes and turn on the servo pump. 9( van brake lights and motion sensor). Only used for three trips so no longterm observations.
Last time out the plug unscrewed itself and fell with wire dangling to the road, leaving part still engaged in the socket. was advised by a passing motorist , stopped and wife drove car home. A replacement cable with 7 wires was sent. I rewired the original with your splendid instructions.
A number of questions
1 have i got any euro6 smart alternator problens in car or van
2 unscrewing plug i have replaced with a manxxx type (can’t remember name) and have a green alignment socket.
3 pin 12 on the socket is not connected in the ducato. Can i run a switched live led from the ducato through pin 12 to earth via the car. Will this contradict the iso spec for the 13pin connection?
Hi John
Pin 12 on a 13 pin towing socket isn’t used.
I would suggest you don’t use pin 12 for running a +ve feed from the Ducato to the car. Changing any of the designated pin connections could have an impact on the Ducato’s MOT in the future depending on what test equipment the MOT station uses.
There is a permanent live available on pin 9 and an ignition switched live available on pin 10. If you need an alternative supply, I’d install a new 12S socket which isn’t part of the MOT testing just for a dedicated separate link.
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Thanks I will ask them as per your post.
They might have installed the OEM package… which is a box that plugs into he vehicles wiring harness…. I’m just basing it from some info from a group on a Mitsubishi forum in Australia that had mainly VSR’s fitted as “standard”… not an OEM kit plugged into the vehicle’s systems. It is a bit different in ‘Stralia’ though.
Thanks Simon. I have since spoken with Mitsubishi and apparently the Shogun does not have a Smart alternator so there must be an issue elsewhere. I think I need to go back to the tow bar fitters for them to check before I get onto the caravan dealer. However others with the Euro 6 issue would be grateful
Hi Ian
Check to see if they have fitted a voltage sense relay rather than ignition switched relay. If they have it might be that the voltage sense level needs adjusting.
Most installers instal these at the rear of the vehicle when in fact it should be in the engine bay.
Installing in the rear is often problematical as when the voltage is correct they turn on and then immediately get a voltage drop due to the current draw using 2.5 or 4mm2 cable and turn off again. However they always test OK with a voltmeter.
If they have installed a VSR get them to test with a 100 watt load.
Simon taking into consideration comments above etc when you have the time would it be possible for you to update your original blog as the issue seems to becoming quite common? We now have a Euro 5 vehicle 2013 Shogun and are experiencing issues with the 12v to the fridge when towing. It seems that both Euro 5 & 6 vehicles have an issue with “Smart” alternators. In addition, the cost of the unit has jumped up from the original £160 to over £230 and more and more people towing caravans are running into the issue. Many thanks.
Hi Ian
I’ve been thinking about a second post about this issue as I am receiving a lot of emails from people that are now having issues since changing their vehicle over the spring/summer. I’ve even had a couple of emails from tow bar installers that have had customers coming back reporting their fridge is not working or their leisure battery is flat even after a few hours towing.
I have rear view camera on my caravan which is powered by the caravan fridge feed so it only comes on when the engine is running and towing. Its useful as it also lets me know that the fridge connection is made.
To get to the point, after several days towing through Europe last year with no problems we set off one morning and the rear view camera was coming on and off intermittantly. This initially looked like a loose connection, which it wasn’t. After looking around the cockpit I realised that the ventilation fan was ‘off’. I switched the fan on and that resolved the problem and I had a continuous fridge feed. It would appear that the alternator needed a ‘car’ load to maintain continuous output.
For background the 12S plug is fed from the car battery thro’ a sensing relay. The car is a Honda CRV diesel 2011 and Euro 4. Altough Honda build in a caravan supply lead it never seemed to work.
Hi John
It sounds like the ECU decided there wasn’t enough electrical load in the vehicle to warrant the alternator running so turned it off to save fuel. This is now becoming an issue for caravaners and motorhomes and your method of connecting your rear view camera (which is a good idea by the way) demonstrates this practically.
If you didn’t have the rear view camera you probably would have never known about it.
Simon,
I noted that when you fitted your Sterling device you bypassed the fuse box as I believe you said a dry joint was causing a voltage drop. Should the incoming supply to the Sterling “Amplifier” be fused and if so at what amperage? Your thoughts please.
Many thanks
Clive Blake
Hi Clive
I have fitted a separate hi quality fuse holder for each circuit and installed a 20 amp fuse in each circuit.
As the cable is 2.5mm2 in the vehicle and in the multicore connecting the caravan to the vehicle, the theoretical max current for this cable size is just shy of 27 amps. 20 Amps keeps it well within limits.
Hi sorry I have Elddis autoquest Motorhome2016 Euro 5 Leisure battery Getting same problem even though I have solar panel I have 8 stage Charger two weeks later battery is down to 12.7
Hi Mark
That sounds like a bit more than the battery self discharging if you have a solar panel. It might be worth checking with a multimeter to see if there is any parasitic current drain on the battery when everything in the motorhome is turned off. (alarm, gas monitor etc.)
I suspect that with that sort of voltage drop your solar panel may not be charging the battery or something is connected and powered that shouldn’t be.
Simon – I cannot apologise enough. The only excuse I can proffer is that I am a relative newcomer to this exciting world of caravanning and over eager to learn more. Your blog and all the various contributions from your regular readers has been of considerable value to me. I will know better next time. Thanks and festive greetings to you.
Hi
No need to apologise.
Some of my posts… the correct way to connect two batteries for example have been linked in not only caravan forums but boating forums… from California all the way to Australia and back to Europe and because of this these pages get a huge amount of traffic…. if someone Google’s “Connecting my house batteries on my 41 foot yacht…” they land on my page which results in me now knowing a whole lot of stuff about electrics on boats.. and I don’t even sail!…. (although if someone has a spare 40 foot catamaran I’d learn!)
Answering questions in the comments section is more productive… as that information is out there for all to see. Some of the questions that I get by email are a lot longer and I’d really like to put them in the main blog as the question and answer I am sure could possibly help others (maybe not so much on the boats)
Simon
Hi Simon – what does it mean when a comment I made 7 December 2017 is ‘awaiting moderation’? Have I done something wrong or not done something I should have? My previous comment is copied as follows:
Hi Simon. My apologies for the lengthy preamble to this post. I’ve only been caravanning for 12 months and still very inexperienced despite having travelled in excess of 4,000 miles since taking delivery of our new 2017 Bailey Unicorn 3 Cadiz in February. We tow with our 2015 Volvo XC60 AWD D5 which, according to manufacturer’s literature is fitted with a Euro 6 engine. I served for almost 30 years in the Royal Navy, first as a chef and then transferred to the RN Police. By way of furthering my knowledge of all things caravanning, I have read a number of your very informative guides and have indeed benefitted from them. However, as I am far from technically minded I have found this guide about poor fridge operation in relation to Euro 6 cars more difficult to fully comprehend. Perhaps I don’t need to? Until now I have only driven 175-200 miles on any one journey with a well-stocked fridge – all contents either chilled down or frozen in my home beforehand and the caravan fridge brought down to a very cold temperature on domestic EHU. I haven’t yet experienced any problems thus far. All of that said, I am considering a trip to France in 2018 and will want to increase my journey miles between stops. Any advice or guidance you may offer would be appreciated. BTW, we live in Helensburgh, Scotland and considering Poole to Cherbourg to cross The Channel. Should I be considering a Sterling Power Wildside or BBC 1225 unit?
Your comment is awaiting moderation.
Hi
I get around 40 emails a week and maybe a similar amount of comments posted directly to the bog. Sometimes It is easy to post a quick reply on other occasions it might take a couple of days to do a bit of research to be able to respond with something that might be close to a useful answer.
As this blog is only written by myself and occasionally by Sue sometimes the emails and comments back up as I cannot respond fast enough. I fit working on the blog and answering questions around my ‘day job’ and If you have noticed I have not been able to post anything for about three months due to other commitments.
The reason I set all the comments to moderation is because otherwise it would fill up with adverts for SEO companies and ad’s for all sorts of rubbish which I have to manually delete.
I don’t advertise or allow adverts, therefore the blog is entirely self funded. I don’t sell stickers, mugs or have a Paterion Account to create an income from the blog even though so far this year I have had around 7.5 million page hits.
I do pay to have a full WordPress Premium account so that related adverts are not inserted into posts. To help cover this I do receive a small amount from Amazon for things I have bought and mentioned in my blog posts, so far it’s not covered the cost.
Therefore there isn’t a team of people behind CaravanChronicles that can respond daily to questions or offer technical advise… I do my best. I’m sorry this my have fallen short of your expectations on this occasion.
however to answer your question. Generally fridges should be OK with Euro6 engines if, as you have done, pre chill them and stock them with pre-chilled stores. A modern caravan fridge should keep things at the right temp if a few hours if not powered and the door isn’t opened. Which is great for a ferry crossing for example.
The issue is that with Euro6 engines in regen mode the regen voltage and in some vehicles has been measured above 16 volts and it is unknown (as far as I am aware) what the upper voltage is of the fridge heating element is and if this voltage could shorten the life of the element or burn it out from prolonged over voltage.
The other consideration is what this high voltage is doing to the leisure battery. Now some vehicle manufacturers are regulating the vehicle electrical system (in my case with a VW Amarok it is 14.7 volts) to prevent higher voltages affecting ancillary equipment.
Some tow bar fitters are still installing the correct OEM 7 pin light circuit equipment and wiring the leisure battery and fridge circuits the old fashioned way directly to the vehicle battery to save installation costs as people often faced with a quote for upwards of £700 for their main dealer to install a OEM tow bar and electrical system prefer to go to the chap down the road that can do it for half the price.
Do you need a DC to DC charger? Well I look at it this way, My battery is receiving the best possible care while on the road. It’s now 6 years old and at the last check on the digital battery test set still performs to about 92% of its ‘new’ performance figures and hopefully I won’t be parting with the folding suff for a new battery in the near future. With regards to the fridge, again hopefully as the heating element is supplied with the correct voltage it will give me good service and a long life. I don’t know how easy or not it is to change a fridge element… but I don’t really want to find out.
Merry Christmas and happy touring for 2018.
Simon,
Thanks for your input and have a happy Christmas. Your efforts are appreciated.
Would fitting a VCR into the feed to the caravan battery overcome the problem of caravan battery drain? Or would the backfeed from the caravan interfere with the VCR operation?
Simon
Just to let you know I managed to buy one at 0600 this morning. At 1015 all had sold out. Price is now £236.40 delivered. Any updates on how yours is performing?
I have bought last night one from sp-shop.co.uk for £192.78 inc vat and free delivery. Just had a look at the website and they are still listed as in stock.
David,
Thanks for that. I contacted Stirling Power Products and asked for an explanation regarding the price. They agreed I could return the product for a refund and offered to collect. They then recontacted me and stated they would match the price quoted by you which is one of their distributors. Credit to them for customer relations. They did say they have no more in stock at the moment as most, I would imagine, are now with their distributors.
Thanks for the heads up which has saved me a few quid to say the least!
Now all I have to do is read up the installation instructions.
Hi Simon,
This maybe of interest regarding regen-braking vehicles i.e. Euro 6 etc; Thus far I’ve not been able to confirm this so please don’t quote me. I have heard that said approximate percentage 80/20 ratio for charging & space left for boosting on regen is not set in stone. It is variable according to the surrounding ambiant temperature. This is to allow the vehicles’ battery to charge to a higher percentage (possibly even up to 100%) in constant subzero temperatures to optimise cold subzero degrees, morning starting. A vehicle battery being possibly allowed to discharge down to 75/80 %, could certainly hinder starting a vehicle at say minus 6 degrees. If this is correct? This could mean the colder it is, the less is genarated by regen-boosts? Which could mean it acts more like a standard system in these cercumstances?
Colin
Hi Colin
I’m not sure about other makes, but VW use AGM batteries which I think have a better tolerance for temperature fluctuations. I do know last winter though the battery voltage was generally higher than in the warmer months. (I have a digital voltmeter on the dash).
But you do make an interesting point.
Simon,
Just contacted Stirling – apparently not available until November ! I have been trying to buy one since May.
Regards
Clive
Hi Clive
I believe the circuit boards are manufactured in Taiwan (don’t quote me!) and Sterling receive them in batches. From what I can gather, the interest in the units has exceeded their original estimates several times over.
Hi Michael
Many thanks for your reply, at that sort of price I will go ahead and buy one, I must admit, I thought that it would be a lot more than that, so good news, once again many thanks.
Kind regards
Colin
My thoughts exactly Colin!
Hello Colin
The unit cost £150 + £9.60 postage.
My 22 year old Range Rover has also benefitted. It delivered 11.7v at the fridge whereas, with the Wildside module, 14.4v.
Michael
Hi Simon,
As a matter of interest, do you know the current RRP of the Wildside module, if it’s not to expensive, I may fit one to my Caravan even though my towcar is not a Euro 5 or 6 and does not have regen braking or even a smart alternator. Undertaking this will also give me knowledge for when I’m moonlighting for extra pocket money.
Colin
Hi Simon,
Once again (as usual) excellent write up/report. Many thanks an behalf of us all for taking the time to post this information. I would also like to thank others as many of the replies were interesting reading too.
Hello Simon
Just a quick note to thank you for the notes regarding the Sterling Power Wildside unit.
My main tow vehicle has a Euro 6 engine and the van – a 2017 Coachman Laser 620 – has exhibited all of the problems you have encountered. With absolutely no help at all from the selling dealer (!) I decided to purchase the BBC 1225 unit and have just completed a long weekend after wiring it in.
Complete success. I have set it on Fridge bias mode as this is our main objective. The 620 has a large absorption fridge requiring 1400 watts and with 14.4v, at the fridge, the draw is less than 10 amps.
Ice stays frozen and power left over to charge the battery.
I thoroughly recommend this product to anyone suffering from Euro 5 or 6 blues.
Hi Michael
Really glad my ramblings have proved useful and you have sorted out your Euro 6 and caravan issues.
I have a sneaking feeling as all the new 2018 caravans start to hit the road in the next few weeks there will be more people converting over!
Very interesting, are they now for sale at last?
Hi Clive
Yes, I believe they are now available
Hello Clive – the unit constantly “appears” to be “out of stock” on the Sterling site. I kept visiting the site until a unit became available – I bought it and immediately they were “out of stock” again. You may have to be persistent!!
Michael.
Hi Simon
It occurred to me that before a journey my leisure battery would be fully charged.
If I fitted an isolator switch to the pin 9 cable, this would stop the car battery from draining the leisure battery. On site, the leisure battery would be kept charged up with the 240v supply, so that on the return journey home, with the leisure battery isolated, I would be able to use my mover to put my caravan onto my drive at home with confidence.
The fridge, I presume would still be getting some or occasional voltage from the car.
Barry
Hi Barry
Personally I’d just install a DC to DC charger, at least it will look after your leisure battery correctly.
I was thinking exactly the same – it would be a lot cheaper than the price of the Wildside unit! I’ve just acquired a BMW with a Euro5 engine, fitted my towbar and wiring, but hadn’t yet appreciated the effect of this type of alternator fitted to this car. so many thanks for flagging this up!
My Mercedes Blue Efficiency has an auxiliary battery in the boot, this battery always carries a charge of around 13v. Could I rewire the 12v caravan cable to this. Would this solve the problem?
Hi Barry
I would not advise it as the Mercedes system is not designed for this, the auxiliary battery is there to maintain a base voltage for the vehicle, where as VW’s for example have voltage regulators to do this for all the vehicle electronics and systems.
Thanks for your reply.
Many thanks for this comprehesive article. I’m not affected as my engine is not Euro 6. An observation – low leisure battery charge annoying on arrival at home but very awkward when arriving on site and motor movers required. I wonder how widespread the problem is. Regards. Neil.
Hi Neil
Quite a few of the emails I get are related to motor movers and batteries and I can’t help thinking that this might be related to more of them than I originally thought.
I am also wondering how many people have bought new batteries as they just assumed that their battery was starting to fail.
It took me a couple of goes to find the difference between the two diagrams, but then I spotted the alternator connection!
I now need to go back to your write up about the wildside unit to see how it overcomes this issue with euro 6 engines again.
Interesting information though thanks for posting it.
Hi
Once you see the alternator disconnected it becomes clear how just the two batteries then power everything including the fridge.
Although in reality the alternator is not disconnected the output is reduced to a level that allows the vehicle battery to discharge.
Each vehicle manufacturer seems to handle regen and the alternator control slightly differently so I have had to generalise somewhat.
I’m trying to get a bit more detail about how these systems work but for obvious reasons manufacturers are a bit reluctant in providing information.
As ever very informative Simon.
Nice write up.
Ian
Thanks Ian.
Another quality report, like them all very much. Could a diode be put in to stop the leisure battery from supplementing the car battery. I don’t know if they make diodes for this kind of thing though.
Hi Mike
A diode would be an answer, however as one that is capable of a forward current of 20 amps would require a heat sink and the probability that you would get around 0.4 or 0.5 volts drop across it which doesn’t help when added tot he cable volt drop a DC to DC charger is more the way forward in my opinion.
Hi Simon
I hadn’t thought of that 😦 We’d been having the same mover problems on a new caravan, mover and battery bought this February and it only happened after long journeys.
Thanks for the all the info.
Mike