Category Archives: Off Grid

Just a quick one…

08 Sunday May 2022

Posted by in Accessories, Caravan Electrics, Electrical, Modifications, Off Grid, Projects, Technical

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Lithium Upgrade for a caravan

I’ve had quite a few people email me asking for more information about the Victron system for a caravan that I was planning mentioned in the previous post. As this seems to have generated a number of questions, rather than give detailed answers to each one I thought I’d post the drawings. For the moment it’s on hold but here are the drawings.

While Victron would seem the obvious choice, there are a number of recent new products from Sterling Power that have rekindled my interest in the project…. watch this space.

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 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.)

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.

IMG_1143

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

 

Getting All Charged Up – Part 1…

25 Tuesday Apr 2017

Posted by in Boondocking, Caravan Electrics, Caravan Servicing, Electrical, Gadgets, General, Maintenance, Modifications, Off Grid, Product Review, Reviews, Technical, tow vehicle, Uncategorized, VW Amarok

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If you are a regular reader you may remember a couple of posts I wrote about leisure battery charging in caravans and motorhomes (Smart Alternators: how they affect Caravans and Motorhomes…. and NEC Show Roundup – it’s all technical…) and I linked to a few videos that Charles Sterling from Sterling Power has produced covering charging topics and Euro6 engines. At the recent NEC show Sterling Power were featuring a new product that would soon be available that would solve all the issues for caravan owners that were experiancing towing with vehicles that had “smart alternators” which were are standard on Euro5 and Euro6 engines and the issues around regenerative braking on Euro6 engines. Charles promised to send me one of the first pre-production “Wildside” Battery to Battery chargers specifically designed for caravans.

IMG_1127A couple of days ago I was excited to receive   a package from Sterling Power containing one of the pre-production new “Wildside” units. The unit itself is robustly constructed and weighs in at about the same as a bag of sugar – 1Kg.

It comes with a comprehensive 11 page instruction/installation manual that goes through all the steps that you need to install the units and what all the various lights and connections are on the unit itself. For anyone that is familiar with my electrical drawings, Sterling have based their installation drawings on my format so are easy to understand (in my opinion!).

I’ll state now for the record, Sterling Power have sent me this free of charge to install and evaluate and that is what I’m going to do, but I will be honest and tell you if I think there are any issues with the installation or the unit in the way that it operates.

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Looking at the connections for the unit it all looks straight forward. The circuit board is labelled  exactly as the drawings in the installation manual which is reassuring and the manual goes into the various functions of each connection and the programming of the unit.

Why this unit?

Since we had changed from using our 2006 Land Rover Freelander HSE as our primary tow vehicle to our 2016 VW Amarok Atacama I had noticed that our leisure battery was not getting close to a full charge even after towing for a couple of hours. We don’t have a solar charging system installed and relied on the tow vehicle and EHU when on site to keep our leisure battery topped up. I knew about the limitations of smart alternators and have written about them before and answered lots of emails about problems readers were now experiancing. Up to this point I really didn’t have an answer to most of the problems and I was considering going down the same route as our Australian cousins and installing some hefty cables between the tow vehicle and caravan, connected together with Anderson connectors. Works fine down under and would do here, especially coupled with one of Sterling Power’s B2B units which I had been looking at.

Now this would be ideal for us, but anyone who tows using a company car, a lease vehicle or a vehicle on a LP scheme can’t just go ahead and install stuff willy nilly. Unless it is done right, it has the potential to be a bit of a ticking bomb as well and  if I was going to recommend it as a solution there are very few people with experience to do an installation of this type. I have seen some right botch jobs on heavy-duty cabling by so-called “professionals” when installing simple winches and dual battery systems on 4 x 4 off road vehicles. Using a lump hammer, cold chisel and block of metal is NOT the professional way to crimp battery cables!

I was looking round to see if there were other options and talking to the chaps on the Sterling Power stand at the show told me they had a product in development that might just be the solution…. and here we are!

How does it work?

I’m not going to give you chapter and verse on the internals (some of that would be guessing on my part and some is propriety information anyway) so I’ll simplify it as much as I can.

In current tow vehicles you have two connections that supply power to the caravan – one for the fridge which is only live when the engine runs and one for charging the leisure battery which is usually live all the time.  Now the problem is that as it’s quite a distance from the front of the vehicle where the battery and alternator are to where  the leisure battery and fridge are located in the caravan. The size of the cables providing the connections are key to how efficient it all works.

Nearly all good quality tow bar wiring uses 2.5 mm square (2.5mm²) cable for these circuits and they connect between the tow vehicle and caravan through a 13 pin plug and socket (or 12N & 12S in older vehicles). The problem with all this is down to good electrical ‘laws’. In essence the more current you draw through a length of cable the greater the voltage drop ( I go into a bit of techie detail about it here… Understanding Cable and Cable Sizes ) Some people go to the lengths of re-wiring the circuits in 4mm² or even 6mm² cable, which was OK up to a point… usually the point which is the connection between the vehicle and caravan. With the traditional installation what you end up with is two circuits that the voltage is usually too low to provide a good charging capability for the leisure battery and the fridge circuit that might or might not, depending on voltage drop, have some spare capacity but you can’t use it to charge the leisure battery.

Back to the Wildside unit…

What the Wildside unit does and this is really clever, is it takes over the two power circuits, aggregates them and manages the output. It draws the maximum current available through each of the two circuits and provides an output for the fridge always at the correct voltage to maximise the efficiency of your fridge and protect it from the voltage fluctuations inherent with Euro6 and Regen engines and any spare capacity on this circuit it added to the leisure battery charging circuit, steps up the voltage and provides a separate output via a four stage intelligent battery charger to maximise the charging capability to your leisure battery.

This is a very very simple one paragraph explanation, it does have a few other tricks up its sleeve though.

One feature is the “Remote Mode Select” switch option. This allows you to install a switch that will allow you to turn the unit to “Wildside”, “Boondocking” or “Off Grid” mode and run the fridge as though it was being powered from the vehicle. It is actually being powered from the leisure battery.

Take note though… Most caravans and motorhomes are fitted with absorption fridges which use a heated element that is constantly on to make the fridge work. However some motorhomes ( I don’t know of any caravans) are fitted with the more expensive and vastly more efficient compressor fridges which work exactly like your fridge at home but can’t run on gas. If you are camping off grid for a few days with an absorption fridge, then run it on gas. However if you are worried about your fridge not maintaining temperature on an hours ferry crossing or on a euro tunnel crossing then you can use the switch to keep the fridge running. The period you can power it will depend on the capacity of your battery(s)… I would not advise using it with and absorption fridge on a battery bank with anything less than 110Ah capacity.

If you do use this feature on the Wildside unit, it will protect your battery bank from discharging past the safe point by turning off the fridge when the voltage reduces and reaches a critical point that would damage your battries.

You also have the ability to specifically select the type of leisure battries you have installed – GEL I, GEL II, AGM I, AGM II, Sealed, Open, Calcium, LiFePO4 to get the correct tailored charging and maintenance program for your battery bank.

If you are fortunate to have lithium leisure batteries there are a couple of other connections you will need to check out too.

Installation Considerations…

We know what it does so how do we connect it. Well this is where it could get messy unless we have a plan.

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In essence, what do we need to do? Well we have to cut and divert the incoming pin 9 and pin 10 into the Wildside unit and connect one output to the leisure battery. We also need to disconnect the fridge from the caravan’s original control box and reconnect it to the Wildside unit. As the habitation relay is usually buried inside the original control box we need to be able to control this from the Wildside unit. There is a terminal for this (“CVan Dis Output”) but what do we connect to this to make the habitation relay operate correctly?

The original Pin 10 lead that we cut and diverted into the Wildside unit, the other end of this still goes into the installed control box and this will operate the habitation relay. Remember we disconnected the fridge power lead from the installed control box and reconnected it directly to the FRG+ output on the Wildside unit so all it does now is operate the habitation relay.

So summing up, we have to cut 3 cables and re-terminate 5 ends into the Wildside unit. This of course does not include the neutral connections which will be easy and straight forward.

Other Considerations…

The installation of the Wildside unit must be easily reversible so it can be moved to another caravan at some point in the future.

We must also use the correct size cables to connect to the leisure battery as we will now be charging at higher currents than was possible before, the original cable that was installed in the caravan to connect to the leisure battery may not be of a sufficient rating.

We must document the changes properly so that at some point in the future someone can follow what we have done incase they have to fault find.

We must make sure all the connections and general installation are done to a high standard to ensure the installation is safe.

Finally we must be able to do the install without invalidating any warranty on the original installed control unit (i.e. not opening it up) and retain functionality of all the elements of the caravans electrical system. It’s no use installing the Wildside unit if half the electrical features of you caravan don’t work afterwards!

IMG_1130In Part 2…

In the next part I’ll go through the manufacturers electrical schematics of the caravan and show how to find and trace  which cables we are going to look for when we do the install and how we produce a simple drawing showing the changes.

I’ll also come up with a quick check list for all the additional bits (cable, terminals etc) that we will need for the install.