Flat starter battery

[funkyegg]

I went to the van to get the windows open to reduce heat in these hot weather but I somehow forgot to remove the car key....as a result, the starter battery went completely dead. I'm now plugged in and charging the van as the manual says the auxiliary battery and starter battery are linked so the starter battery can be charged when you are charging the auxiliary battery. The dashboard has no sign of life at the moment so hopefully it will make a difference overnight. Has anyone actually experienced this and can confirm the starter battery can indeed be charged when you are charging the auxiliary battery?

Thanks

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[SteveR]

I went to the van to get the windows open to reduce heat in these hot weather but I somehow forgot to remove the car key....as a result, the starter battery went completely dead. I'm now plugged in and charging the van as the manual says the auxiliary battery and starter battery are linked so the starter battery can be charged when you are charging the auxiliary battery. The dashboard has no sign of life at the moment so hopefully it will make a difference overnight. Has anyone actually experienced this and can confirm the starter battery can indeed be charged when you are charging the auxiliary battery?

Thanks

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Once you plug the mains in it will charge both the aux battery and the starter battery providing certain conditions are met...

 

[funkyegg]

Once you plug the mains in it will charge both the aux battery and the starter battery providing certain conditions are met...


View attachment 1578

Thanks Steve. It's been plugged in overnight but the starter battery is still flat so I think the voltage is too low for it to start charging...

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[SteveR]

Thanks Steve. It's been plugged in overnight but the starter battery is still flat so I think the voltage is too low for it to start charging...

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You may have to try charging the starter battery directly to give it enough voltage. A battery tender, e.g. CTEK or Optimate may be able to salvage the battery if it is extremely flat

Good luck

 

[BurnBabyBurn]

I've had this too, there are more conditions that need to be met than is in the manual according to the Mercedes Milton Keynes technical centre. The key must be out of the ignition and the vehicle must be in Electronics state 0 - which basically means take key out, open drivers door, close drivers door, that turns off all the electronics and comand system etc. Then the battery will charge off the hook up.

 

[funkyegg]

I've had this too, there are more conditions that need to be met than is in the manual according to the Mercedes Milton Keynes technical centre. The key must be out of the ignition and the vehicle must be in Electronics state 0 - which basically means take key out, open drivers door, close drivers door, that turns off all the electronics and comand system etc. Then the battery will charge off the hook up.

That's good to know, thanks.

I had to call Mercedes roadside assistance in the end and the guy had to use both his jump starter and linking to his van battery at the same time to get the car started...

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[BurnBabyBurn]

Same, our first trip out we ended up stranded on a CAMC site, we waited 5 hours for MB Assist (RAC) to arrive. They checked the battery charge and there was 7.4V left in the starter battery. I then took it into MB, they had it for 10 days and couldn't find anything wrong. At first they claimed the hookup didn't and wasn't supposed to charge the starter battery, to which I directed them to the manual. They then logged the ticket with Milton Keynes.

 

[SteveR]

Same, our first trip out we ended up stranded on a CAMC site, we waited 5 hours for MB Assist (RAC) to arrive. They checked the battery charge and there was 7.4V left in the starter battery. I then took it into MB, they had it for 10 days and couldn't find anything wrong. At first they claimed the hookup didn't and wasn't supposed to charge the starter battery, to which I directed them to the manual. They then logged the ticket with Milton Keynes.

Did you (or MB) get it resolved in the end? Sounds very odd behaviour

 

[Samebutdifferent]

Clueless, absolutely clueless!!! That sums up MB technicians regarding their knowledge of the charging electrics.

I've mentioned in a number of threads that I'm finding it impossible get any info regarding the split charge system in the MP, or anything on the general electrical setup whats ever.

 

[Method7]

Clueless, absolutely clueless!!! That sums up MB technicians regarding their knowledge of the charging electrics.

I've mentioned in a number of threads that I'm finding it impossible get any info regarding the split charge system in the MP, or anything on the general electrical setup whats ever.

Hey SBD have you tried westfalia? Seems to me that all of that is most likely installed during the conversion.

 

[James G]

The CTEK MXS 7.0 trickle charger is exactly the same as the MB branded trickle charger but half the price and resurrects a completely flat MP starter battery. I had a faulty ventilation switch which MB took ages to diagnose that meant my starter battery regularly went flat to the point where jump starting wasn't enough. MB technicians kept trying to blame me for not driving the van frequently enough which was refuted by the MB assist person who I had to keep calling out.

 

[Samebutdifferent]

Hey SBD have you tried westfalia? Seems to me that all of that is most likely installed during the conversion.

Not personally but Rob at Campersales has asked the question a number of times. There's someone he contacts who is usually reliable, but seems to have changed roles. He tells me the others aren't much help.

 

[BurnBabyBurn]

Did you (or MB) get it resolved in the end? Sounds very odd behaviour

Sort of, yes and no, since I've followed the recommendations I've had no problems, but I have to say the trip when the battery went flat was our first trip away since picking it up. It was a fairly lengthy drive to the site so the battery should have had a decent charge on the way there. We were on a fully serviced site, we booked this purposely to test and try out the MP, so the doors were frequently opened and closed lights on etc. now that we're more comfortable with the setup we've had no issues. I am suspicious though that they've swapped the batteries round, as the leisure battery is identical to the starter battery. The stop/start would take ages to come on line before, if at all, since MB have had it it appears much better.

 

[BurnBabyBurn]

Clueless, absolutely clueless!!! That sums up MB technicians regarding their knowledge of the charging electrics.

I've mentioned in a number of threads that I'm finding it impossible get any info regarding the split charge system in the MP, or anything on the general electrical setup whats ever.

I know what you mean, I'm an engineer (not electrically biased but know enough) I had a multimeter across the battery terminals on the drive at home with the van hooked up and I knew that with a few simple tests the charger was working, as when the conditions in the manual were met, plus the additional conditions that Milton Keynes gifted, there was a noticeable rise on the starter battery voltage at the exact time the leisure battery reached 13.9V.

All MB do is hook it up to the Star system and if there're no standing faults they're stumped.