Flat starter battery Dethleffs Globeline

[Colin H]

Hi All,

First posting and it’s involving an electrical issue.

Went to collect the MH from external secure storage today and it wouldn’t turn over / start. Quick look at the status panel above habitation door showing leisure batteries 13.8V and starter battery 12.2V. The vehicle has been stationary since returning from a habitation service on 8th July and is a year old.

Even whilst unable to access during lockdown over the Winter subsequent starting was never a problem.

Managed to borrow starter battery / trolley from site but still unable to turn over (unable to verify charge in borrowed trolley).

Started calling Mercedes assistance whilst clock ticking down to compound closing time of 18.00.

After 40 minutes on hold drove home and after 50 minutes got through to be told you can’t pre book for tomorrow morning as system is “live” and to call again in the morning.

So whilst waiting for the morning I’ll pick your brains and ask;

How likely that the original starter battery has died
The habitation batteries are being topped up by the solar panel, would one expect the starter battery to be on the same circuit?
If on off switch was left on on the services access panel could this cause a drain on the starter battery?

I guess as soon as I can get Mercedes/ RAC out tomorrow we should soon find out re current drain and battery status etc.

Just a bit perplexed as up until now it’s operated flawlessly.

Regards

 

[Spriddler]

12.2v is pretty marginal for starting.
Do you get any lights on the dash?
If so, do they go out when you turn the key to 'Start'?
If 'yes' to above I'd suspect poor battery connections which are failing when the heavy starter current is required. Possibly a poor battery to earth strap. In that case connect a heavy lead, e.g. a jump lead between the earth battery post and a clean metal part of the body and try again.

There are other possibilities but the above will be a first step.
Even though the battery is only a year old they can just die when put under a high current demand.

 

[Badknee]

12.2v and wouldn’t turn over doesn’t sound right. Did it not try? We’re there any lights on the dash?

 

[Colin H]

There were lights on the dash but no dimming of them when I attempted to start, no noticeable clicking either of starter solenoid (if still used?). Given the engines a 4 cylinder 2.2 L diesel maybe there’s some sort of management system that’s looking for say >12.8V before attempting a start?

 

[Spriddler]

Ah, well if the dash lights don't go out it's not likely to be a battery earthing fault but perhaps a chassis to engine (starter motor) fault.
I'm not familiar with Merc circuitry/switching so out of my depth with them.
Do immobilisers allow the dash lights to come on but inhibit the starter motor?

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[Scotch mist]

Sounds like a flat battery to me , the clicking noise fron a solenoid is normal , unlikely to anything else , they can discharge over time especially if tracker etc are fitted ,

 

[Podney]

My servicing guy told me that the voltage read out in the panel is not very accurate,so maybe it’s less than 12.2.

But,if it is 12.2 I would expect it to attempt to turn over.

In days gone by we used to thump the starter motor or put the vehicle in gear and rock it,but that’s a bit difficult with a heavy motorhome…….and probably not effective on modern vans anyway.

You could try a starter pack on it.

 

[Diabalo]

The habitation batteries are being topped up by the solar panel, would one expect the starter battery to be on the same circuit?

Not necessarily, you need to check your user manual, on my auto trail with the panel on I can select the solar panels to charge either the Hab batteries, the vehicle batteries or smart charge where it charges one after the other but in the winter I find the smart charging not very good.

If on off switch was left on on the services access panel could this cause a drain on the starter battery?

I have found that on my Auto-trail to minimise drain it's better to turn off the control panel and have a battery master between the Hab and cab batteries to keep the cab battery topped up.

Don't rely on the panel readings, use a multi meter directly across the battery to determine the voltage.

 

[autorouter]

If you have a jump lead you could connect the leisure battery positive directly to the starter battery positive. There would be an initial high current flow, then over the next few minutes the charges would equalise so that both batteries would be about half charged. Then disconnect the jump lead. With any luck the engine will start, and the solar will refill the leisure battery eventually.

 

[HugoBNB]

Happened all the time to us until we purchased a £35 solar panel and adapted it, using crocodile clips to fit onto the vehicle battery. No issues since then. Apparently it is a known issue on our Ducato model that there is a voltage leak. Other threads on here on the subject too.
Hope you get sorted.

FYI 25w flat portable panel. We extended the cable to put it on the roof of the building where we store the van. If you are outdoors, and your can is pointing South, it would fit nicely on the dashboard too.

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[IRHP]

Sounds like it's just gone flat there is always a percentage loss and anything else that's drawing current. Alarm, radio, tracker etc. Your solar set up may or may not charge both batteries depending on type. You would need a dual solar output controller to charge both.

 

[Guigsy]

Happened all the time to us until we purchased a £35 solar panel and adapted it, using crocodile clips to fit onto the vehicle battery. No issues since then. Apparently it is a known issue on our Ducato model that there is a voltage leak. Other threads on here on the subject too.
Hope you get sorted.

FYI 25w flat portable panel. We extended the cable to put it on the roof of the building where we store the van. If you are outdoors, and your can is pointing South, it would fit nicely on the dashboard too.

If you've got solar, a VanBitz Battery Master would trickle the cab battery:
[Broken Link Removed]

 

[Colin H]

Sorted. First of all thanks for all your contributions.

Stand by……..wait for it……….the battery in the key fob of the scorpion tracker was flat!!!! automatically locks out the engine apparently. So RAC man scratching his head at first, call to dealership and call from tracker (sensing interference with vehicle) got it sorted. Scorpion have temporarily disabled immobiliser until key fob batteries replaced.

On another slightly related note, Mr RAC wasn’t able to access the diagnostic port as part of his initial fault finding. It seems the dealer had left attached an OBD port protector which had been fitted whilst awaiting purchase in the dealers compound. Seems they had forgotten to remove it or offer us the option of keeping it on along with a removal key.

 

[Podney]

If the battery in that key fob runs out after just one year,you may have troubles ahead! I guess they are readily available though.

 

[Guigsy]

If the battery in that key fob runs out after just one year,you may have troubles ahead! I guess they are readily available though.

The tracker fob continuously broadcasts a signal. If the tracker in the van can't detect it, it immobilises the vehicle.

Ours is similar, except we get a phone call from the call centre asking us if we want the van disabled (because it's been nicked), or did we just forget the fob.

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[HugoBNB]

Pleased you are sorted