Battery drain - Mercedes Burford Duo

Hi there, we are MicknHelen and this is our first post.  We bought a 2014 Burford Duo with 1500 miles on the clock and we constantly have the vehicle battery draining within 3/4 days.  We have had a new battery after 6 months and it is still the same.  We had a tow bar fitted but are not sure whether that would have anything to do with the problem. It is draining the battery to where there is not even a light on the dash and believe it has now killed the new battery.  Has anyone any ideas?  Leisure batteries are fine.  Thanks in anticipation.

Hi Micknhelen
Welcome to the forum from sunny Bridlington , one of the Burford owners or Similar van will help you.
Boaby

I imagine that the electrical system is similar to our Symbol which we bought new this year.
I usually keep it on hook-up to keep everything in order. When I left it off hook up for a couple of weeks, the vehicle battery was found to be flat (not even enough power to open the doors with the remote) and I was told that I should have used the System Shutdown switch if not leaving it on hook-up.
Have you used System Shutdown?
John

Thanks.  I didn' know there was a shutdown switch for the vehicle battery. I have switched off the one on the interior but it makes no difference to the vehicle battery.

If there is, it should be mentioned in the handbook - for the Symbol it's on the page that deals with the main switches for heating and battery charging. On ours that switch box is inside a cupboard along with the main fusebox and trip switches.
John

Maybe you have got the "active battery" on your control panel set to vehicle and not leisure?

I believe the shutdown system is for the leisure battery, do you have a solar panel?

Thanks everyone.  I switch it to the vehicle battery and charge fully with a generator, then switch it back to leisure and then switch the habitation side off with the main isolation switch.  But within 2/3 days the vehicle battery is totally flat.  It is parked up in a compound.  I think our only option is to find a decent auto electrician to check all the electrics, battery etc - something is draining the vehicle battery.

From your description above I would guess that your motor-home is still within its warranty period, in which case I would be inclined to take the problem up with either your local Mercedes (commercial) dealer or Auto Sleeper (Willersey) in the first instance rather than have some outside specialist poking around. 

If you are switching the habitation control system off when the van is in storage then the likely drain would appear to be something within the base vehicle itself -  has something been added recently to be a potential cause of this drain?

My van can remain without EHU for several weeks and still hold its charge in both batteries - we have an 80 watt solar panel fitted and in the summer months this should be more than capable of maintaining both batteries at their optimum charge whilst in storage.

Liam

Thanks Liam,

For sure the warranty route would seem to be the best way but since we have had a tow bar fitted we feel we need to get that checked out before we go to Mercedes or Auto Sleeper.  We have had two Autotrails before this van and never had a battery problem leaving those standing for a while.  Driving us mad!!!

It does seem an issue on modern vans! I coukd leave my Hymer for 3 months when laid up. The Lancashire flattens both batteries in a few weeks - but at least not in a few days! We don't have a solar panel.

Did you have the towbar fitted at the time you bought it and have you mentioned your suspicions to the towbar fitter?
If you had the van for a few days before the towbar was fitted and the battery stayed charged, I would agree that the towbar would seem to be a clue to the problem but i'm sure you would have used a reputable fitter. 
Keep us informed of the outcome if you can.
John

Apart from the towbar issue, have you had an after-market alarm fitted. These seem to be a main culprit of battery drain.

Thanks guys, the alarm was fitted by the first owner so was on the motorhome when we bought it.  We had the tow bar fitted after we bought it.  We will let you know if we manage to sort this.  We have also considered writing to the previous owner to see if he had any problems, the van was registered in May 2014 and we bought it in Jan 2015 with 1500 miles on the clock.  6 months doesn't see a long time to keep it for something that costs what it does.

My first van, a new Swift, had problems that nobody seemed able to rectify, it was driving me crazy and spoiling my motor homing experience, only answer was to get rid and start again. Maybe this is the same scenario by the first owner? I hope not but although we have had some minor problems with our present van, they have been easy to sort out. Nothing worse than setting off on a three month European trip with the thought that problems were going to spoil the trip. Hope you are able to sort it out.

micknhelen,
A thought - 
The EC500 PSU on your vehicle, incorporates a built in solar charge management feature (called an intelligent system as it directs the appropriate charge to the required battery as necessary)  - so if you are turning the shutdown button (its the button on the top row - left hand side) on the EC500  OFF whilst in storage then the solar panel will charge the leisure battery ONLY! 
For the system to operate intelligently, the shutdown button should be left in the ON position!! 
Your owners manual section 7 I believe covers this.
Hope this helps,
Liam

Could it be worth thinking of an MPPT solar charge controller? They are reputed to be far more efficient at capturing intermittent bursts of sunshine to maximise the charge during a cloudy day.

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Dave

Dave,

I believe you will find that the on-board Sargent ECU 500 does all of the above and more - servicing both batteries as necessary - it has an intelligent three stage charge process.
 
Initially, at stage 1 it gradually increases the charge so as to protect the battery, it then delivers the bulk charge at stage 2 and when fully charged reverts to stage 3 where a float charge is delivered to both batteries - providing you leave the shutdown switch in the ON position!!

I would not be inclined to add any other gizmos - particularly on a van that is still under warranty.

Liam

Thanks Liam

I don't know about that ECU, but I was led to believe that the EC325/328 is a bit rudimentary w.r.t. controlling the solar power.

However, my knowledge and understanding of electronics is legendary. It fluctuates between low and undetectable!

Dave

Hello MicknHelen, in the majority of cases this is a case of shutting down the system completely with the isolation switch on your Sargent system, not the panel the actual consumer box. If this isn't done the system is still live and uses the strongest battery so switches between vehicle and leisure thus resulting in flat batteries. Annoying I know and don't ask me why we don't know, I do know this is being looked into.


Regards


Mark 

It's true that an MPPT controller is likely to be more efficient, but the problem is that any gain is only likely to be a few percent - the big gains for MPPT controllers are on large arrays with multiple panels - because it can optimise the efficiency of each panel individually. A few percent in this situation is (IMO) really not worth having - it just means your battery will go flat slightly slower!

But it should really just be a matter of going back to the basics: If the battery is going flat it's either a bad battery or a current drain - there are no other credible options. If there is a battery current drain, it can be measured, easily, with a cheap meter. Once a battery drain is proven, the source can be identified by a process of elimination (i.e. by removing fuses until the battery drain stops). Any good auto electrician should be able to do a diagnostic job like that, and it shouldn't involve more than a couple of hours work.

In my experience there are only a relatively small number of things that cause excessive battery drain: Alarms/trackers, mis-wired aftermarket radios and USB power supplies (for satnavs, dashcams, Ipods, etc.) permanently wired to an ignition-off battery circuit are the typical culprits.

Ditto Mojo.

Learning something new every day!

Dave

-mojo- wrote:

But it should really just be a matter of going back to the basics: If the battery is going flat it's either a bad battery or a current drain - there are no other credible options.

In my experience there are only a relatively small number of things that cause excessive battery drain: Alarms/trackers, mis-wired aftermarket radios and USB power supplies (for satnavs, dashcams, Ipods, etc.) permanently wired to an ignition-off battery circuit are the typical culprits.

And I agree 100%.  I would just add that there is always an unswitched connection from the starter battery to the Sargent system (includes habitation wiring loom), so that needs to be factored into the investigation.

Gromit wrote:Thanks Liam

I don't know about that ECU, but I was led to believe that the EC325/328 is a bit rudimentary w.r.t. controlling the solar power.

However, my knowledge and understanding of electronics is legendary. It fluctuates between low and undetectable!

Dave

Not so - the EC325 and 328 are fine