Wallas XC Duo & voltage issues

[Stewby]

Hi

Firstly forgive my lack of knowledge of electrics, but i'll try and explain things as best I can.

I am looking for some advice before going back to my convertor about an issue we have with the Wallas XC Duo and battery voltage. Our setup is Wallas hob/heater, fridge, lighting supported by a 12V 110AH SuperBatt LH110 leisure battery and 100w solar panel. Here's what happened on a recent trip and can be replicated as I did tonight.

We drive to a destination (1 hr +) off grid and in the evening we start the hob to cook dinner in the evening. It should be noted the fridge is on, but probably not cooling as it would already be cool and is on a low setting. A few lights would also be on. The voltage is sitting around 13.2 or 12.8 depending if there is any light outside for the solar. I start the Wallas hob as normal and you can see the voltage work its way down to about 12.1 during 5 mins or so as the heater begins the start up phase. After about 10 minutes or so once the hob has started and is producing heat, the voltage came back up to 12.5. I ran the heater for about an hour, which would be usual for cooking something and getting a bit of heat. I now switch off the heater and let it do the cool down. After about another hour I check the voltage and it shows around 12.3 with again two lights on, fridge likely idle. I start heater for some evening heat and after about 30 seconds to a minute I see the voltage go from 12.4 to 12.0 and the heater turns off, flashed yellow which is low voltage warning.

The heater/hob no longer works at all until we get some sunlight back in the morning, plug in to 240 or I haven't tried it but probably starting the engine for a while would help. Should I really need to do that? My question is, is this normal behaviour? Can I really only run the Wallas once and that's it? We did change out the battery for the same sort a few weeks back as we initially thought we had a duff battery, but the problems remain.

I see there are many people using the Wallas but I haven't really seen anyone complain about only being able to use it once per night. It leads me to believe we are either doing something wrong or have an electrical issue somewhere. What setups are you Wallas users using and how many times can you start the device while off grid at night or in the dark?

Thanks in advance.

 

[Dellmassive]

Have you tried charging the battery over night with a proper smart charger?....then retest.?

A 1hr drive won't change a low battery.... It may take 5-10hrs drive.

Same with solar, that will not charge the battery up... 100w will not be enough to offset the fridge and lights running.... And defo not the heater.

What DC-DC charger have you got for engine charging?


Post some pics of the batterys and your setup.

 

[Stewby]

Thanks for the reply.

I may only have done an hours run most recently but we are ofent on very long drives as we make trips from Scotland to England. On a recent trip on about a week ago we drove a good 7 hours back up to Scotland. I would like to think that would have charged the battery. Also, on about 5 of 7 nights we were on 240v hookup at campsites so again would like to think the battery kept charged.

Here are a couple of pics of the wiring diagram provided by the convertor. It's on an A3 sheet so had to take two photos of it. It's not my work, it was just provided by the convertor. The battery to battery charger a Ring DCCHARGE30. The battery we use is this one here 12V 110AH Solar Leisure Marine Battery Low Height Low Profile - SuperBatt LH110 | eBay

 

[stu3467]

I have a Wallas but not had to use it yet off grid as the weather has been pretty good for me! Obviously no problem on EHU.
However I run it every now and again on my drive and you are right that initial startup takes a lot out of my battery . I read somewhere to run the engine for the initial couple of minutes start up if it refuses to start due to low battery .Once its running the draw seems to be very low just a pain in the arse to get going if your battery isn't 100%

 

[Dellmassive]

Looking at the schematic it shows a EC50 controller.

That would imply you have a Sergeant EC155?

If that's so, it's well documented that the EC155 is not very good as a battery charger.... It's more a 12v power supply. (For when on EHU)

I note you have a Ring DC-DC with solar?..... I'm assuming it's a 30A model?.. from engine alternator.

And that the 100w solar will give you 6A max charge.

 

[Dellmassive]

That battery is not a great option.



It's a 110ah standard lead acid, heavy duty... Being SLA you can only use 50% of that capacity.... So that leaves you 55ah to play with.... Another issue is the battery voltage will drop off fairly quickly.



One option it to swap it out for an AGM type SLA battery..... That will give you a higher voltage for longer.



Or my personal option would be to swap out for 100ah lithium battery. (You will need to see if the ring has a lithium profile). And look at fitting a EHU charger.

 

[Dellmassive]

more info on DC-DC, chargers, solar, batterys and lithium see here:

Dellmassive’s "How I Done It" blogs.

-- Dellmassive`s -- "How I Done It" -- thread -- ************************************************** Dellmassive`s -- "how I Done It" -- Thread ************************************************** Kit List And Stuff -- How I Done It & What I Use --...

www.t6forum.com

.

 

[Sim60]

I've just been out to my van and started up my Wallas - The Starting phase takes about 7.5A for around 6 mins to get the cooker going (peaks at 9A)- This then drops to just over 0.5A. My shunt shows 0.8ah consumption to get the device going with an ongoing 0.5ah for every hour that its on after that. Your battery should be easily capable of starting and running the heater multiple times if it starts fully charged and depending on other loads.

I think you may have 2 issues .
Where are you measuring 12.0V when the Wallas goes into undervoltage? - The spec for the device is 10.7V for this to happen. This suggests that you may have signifcant voltage drop in your wiring from Leisure battery to the Wallas ie the wiring has too small a cross section.

I don't have the spec for your battery, but if the terminal voltage is dropping to 12V under a 9A load then it sounds like it might already be down at 50% discharge ( battery voltage under load can be much lower than an 'unloaded battery') -So either you've already used a large amount of your battery capacity or it's not being fully charged.

Simon

 

[Stewby]

Thanks for these responses. I can confirm we do have the Sergeant EC155 as well. My father in law who does know more about electrics is coming to similar conclusions about the voltage drop perhaps being something to do with the wire between battery and Wallas, as you also say. I was measuring the voltage at the battery terminals as that's all that was possible. I know in the Wallas booklet it says to measure it at the device but that's very hard to get to once installed. Something we are considering is putting in a new wire direct from battery to Wallas to see how this works.

 

[oldiebut goodie]

I have seen heater installations with up to 4 joins between battery and heater whereas I supply the kit with terminals for direct connection to the battery. Numerous times people have voltage drop issues due this and wiring size.

 

[Stewby]

Thank you all for your contributions. I think we are going to try a suitable wire direct from battery to wallas to see if this solves and voltage drop issues. I'll of course let you know how this goes.

 

[Changabang]

Hi, here's my experience for what it's worth. We've had our T6.1 LWB 4Mo (Jerba conversion) for just over a year now fitted with a Wallas. We do a lot of wild camping rarely staying in one location for more than one night, so we're moving (charging) most days but often not very far. We have a solar panel fitted which is pretty useless in the winter particularly in Donegal where we spent the last 2 weeks, returning home 4 days ago.

During our trip away we spent 2 nights in Dublin just running off the leasure batteries as there was no hook-up. It was cold and we had the Wallas running from about 4pm till 10pm, plus fridge, laptop and some lights ect. 1st night was OK with the Wallas starting up no problem the following morning. Returning again the following evening Wallas started up no problem. The following morning Wallas tried to start and then cut out. First time it's happened to us and obviously not enough grunt in the batteries. I started the engine in the hope that this might give it a boost and what do you know - Wallas booted up! Whether this approach is a one off or might work in the future I don't know but it's worth a try.

Things I'm learning to be aware of:-
1. I'm fitted out with two 12v 90ah AGM leisure batteries. If you only have one you'll probably struggle particularly in the winter with no hook-up.
2. I believe my Wallas is wired 'directly' to the batteries. Looking on line at the fitting instructions for the Wallas this is recommended.
3. As mentioned above, if your batteries are less than well charged it will take some motoring to recharge them fully. It's also worth noting that (my Transporter) when motoring will charge the vehicle battery to full capacity before it switches to charging the leisure batteries. Therefore short runs to the next camping spot is unlikely to be enough charge time. I tend to leave the engine running at the end of the day for a while in the hope that some charge is going into the batteries. I'm not sure if this is good working practice as it might be that the engine needs to rev at a certain level to charge properly. Maybe someone out there can enlighten me?
4. Sometimes particularly in the morning from cold (winter) my Wallas often needs two attemps to boot-up, with the resulting battery drain.
5. I had considered a Ni-Cad system. Good but silly money...for that price I can change my leisure batteries every 3 years for the next 15 and at 71 years old that will probably see me out.

Maintenance/Cleaning
1. I've always use premium diesel in my campers, never supermarket. I like to think this will help maintain my Wallas also.
2. Cleaning the hob. If like me you finish up with a messy hob you'll have come to realise it's not cleanable when it's hot. On a cold hob I wipe it down with a cream cleaner and then use a plastic 'trim removal tool' and more cream cleaner as a lubricant and rub away the stubborn marks using 'elbow' grease. It takes a little effort but works a treat and doesn't scratch you hob and I've not removed the white ring markings on the hob in the process.
3. I have found no other maintenance guidance for the Wallas other than running it to full capacity once a month when your van is sitting on the drive. I guess this stops the diesel gumming up the 'jet' that sprays fuel into the burner.

If anyone has any info on Wallas breakdowns/malfunctions I'd be interested. For instance.....if the pump fails how do you replace/fix it etc. As this is a pretty vital piece of kit it's only likely to fail when you need it the most. Any thoughts/help welcome.

 

[DXX]

I’ve had a few occasions mid UK winter when I’ve needed to run the engine at 2000rpm for 5 minutes to get the Wallas to fire up, once started as pointed out earlier the current drawn drops significantly and it’ll run all night without issues. My 2x 90Ah marine grade AGMs are 5 years old, also connected to solar so they should be in a good state but obviously not as good as new.
I doubt that fuel quality has any significant affect, these heaters are designed and well proven worldwide for boats, marine fuel quality can vary significantly.
I’m expecting my Wallas to outlast the van and then take a position in my workshop, I suspect the Wallas Customer Complaints Dept might be less busy than the one at the piss fizzy lager company that likes to reckon it make the best in the world.

 

[DXX]

After 5 years service I had a few issues with my Wallas XC Duo not starting at first attempt, after eliminating low voltage, fuel supply and inlet / exhaust issues I decided to fit a Service Kit as supplied by Kuranda UK for £106.92.
The service kit contains;
1x glow plug
1x bottom mat with retaining clip
1x fuel needle
When dismantling a piece of hard carbon came away from the outside of the tip on the existing fuel needle, I suspect that this was reason that it was not always starting first time.
The existing glow plug was in good physical condition and the resistance was the same as the new item at 1 Ohm.
The bottom mat was intact, slightly burnt and very stiff, if you do remove it it can’t be reused.
It appears that combustion was very good as almost no carbon in the combustion chamber and none visible in the exhaust.
I replaced all three items as I had already bought them but I suspect if I had simply put it back together with the old parts after clearing the carbon deposit on the fuel needle it would have run without any issues.
Kuranda don’t supply a detailed service manual and simply state to return for servicing if there is an issue. If you have the tools and mechanical / electrical knowledge it’s a 4/10 job. The unit has to be removed from the van.

 

[DXX]

If anybody with a Wallas XC Duo is having issues with reliable starting it’s worth checking the resistance of the FC1 fuel pump solenoid coil.
My Wallas was starting fine with 12V and above but once the input voltage dropped to around 11.6V it was missing pulses despite the PCB LED showing the voltage was supplied to the coil and no under voltage alarm. It then shutdown with a ‘flame out’ alarm as there was insufficient fuel injected to maintain a flame.
I bench tested the pump with a switchable PSU and it operated all the way down to 7.3V so it wasn’t an obvious defect with the pump.

I decided to fit a new pump. The new pumps coil resistance was 3.9 Ohms while the old pump was 4.6 Ohms, it seems that the coil maybe breaking down although there was no obvious external physical damage.
I wouldn’t expect the coil to breakdown but it could be that the peak 14.5V supply is not helping matters when the engine is running or there is full solar input.
The new pump has a much stronger pulse and the unit runs well.

 

[DXX]

After 5 years service I had a few issues with my Wallas XC Duo not starting at first attempt, after eliminating low voltage, fuel supply and inlet / exhaust issues I decided to fit a Service Kit as supplied by Kuranda UK for £106.92.
The service kit contains;
1x glow plug
1x bottom mat with retaining clip
1x fuel needle
When dismantling a piece of hard carbon came away from the outside of the tip on the existing fuel needle, I suspect that this was reason that it was not always starting first time.
The existing glow plug was in good physical condition and the resistance was the same as the new item at 1 Ohm.
The bottom mat was intact, slightly burnt and very stiff, if you do remove it it can’t be reused.
It appears that combustion was very good as almost no carbon in the combustion chamber and none visible in the exhaust.
I replaced all three items as I had already bought them but I suspect if I had simply put it back together with the old parts after clearing the carbon deposit on the fuel needle it would have run without any issues.
Kuranda don’t supply a detailed service manual and simply state to return for servicing if there is an issue. If you have the tools and mechanical / electrical knowledge it’s a 4/10 job. The unit has to be removed from the van.

The glow plug from Kuranda failed to operate correctly from new, the resistance was slightly to low.
However I found the part number BERU GV 688 stamped on the Kuranda supplied part.

The BERU GV688 is a standard diesel engine glow plug, costs a mere £10.18 from Autodoc.
The Wallas glow plug 362502 costs £51.42 from Kuranda and is exactly the same part, total rip off.

The next challenge is find out who actually makes the Wallas XC Duo fuel pump and locate a more reasonably priced spare.