Leisure Battery Not Always Charging

[Seadawn]

So the replacement gas ignition finally arrived and has been fitted and so far so good plus when I plugged Marco in last night by this morning it was fully charged.

Just one thing left to check on the electrics and we’re all good, that being the waste water level indicator which has been registering nothing for some time but the next trip should give that the okay or not.

 

[Roy C]

So the replacement gas ignition finally arrived and has been fitted and so far so good plus when I plugged Marco in last night by this morning it was fully charged.

Just one thing left to check on the electrics and we’re all good, that being the waste water level indicator which has been registering nothing for some time but the next trip should give that the okay or not.

That's good news.

I've been surprised at how the waste water level on my van seems to take a while to register. I put that down to we use the water mostly to fill the kettle rather than doing a lot of washing up in the van (we often use the washing up facilities at the site) so the fresh water tank empties faster than the waste one fills so hopefully you're seeing the same rather than it being a problem.

 

[Katie]

Mine does not register as filling up for quite a long Time although the fresh water one shows earlier.
Its not really accurate - just give an idea when it’s nearly full

 

[Ian]

Interesting thread as this sounds similar to my experience.

My van does not seem to ever register a full charge. I can leave it plugged in for a few days charging (voltage goes up to 13v - 14, shows plug symbol on the control panel, bar indicator flashing - so all good here) and pretty much as soon as it is disconnected the bar indicator drops to 80% and the voltage registers at ~12.5v with nothing turned on. If left unused for a week or so and with nothing turned on the battery is then registering ~12.3v. Once charged it does seem good enough to last a couple of days off grid with light use this summer (fridge on setting 3, occasional use of other electrical items etc) but the voltage is approaching 11.9v by the end of the weekend if we've not driven around.

I understand the type of battery to be fitted to the MP to be a AGM battery and therefore the voltage to charge state to be as per the below table (Reference here):

Gel battery voltage
state of charge----Voltage
100%---------------12.80+
75%----------------12.6
50%----------------12.3
40%----------------12.2
25%----------------12
0%-----------------11.8

I'm inclined to believe that at some point prior to me getting the van that the battery was left in a discharge state for a period of time which has partially damaged its performance so it won't ever reach a full charge. Sound familiar to anyone and has anyone been able to convince their dealer that it was their problem to sort out? Or has anyone coughed up for a new battery?

As a related question does anyone know which seat the leisure battery is under for a right hand drive, UK spec van? The manual states the leisure battery is under the drivers seat but all pictures in the manual show a continental left hand drive van. When spinning the passenger seat of my van (UK spec) I can see a battery beneath it with a sticker that says starter battery.

 

[GeorgeG]

Interesting thread as this sounds similar to my experience.

My van does not seem to ever register a full charge. I can leave it plugged in for a few days charging (voltage goes up to 13v - 14, shows plug symbol on the control panel, bar indicator flashing - so all good here) and pretty much as soon as it is disconnected the bar indicator drops to 80% and the voltage registers at ~12.5v with nothing turned on. If left unused for a week or so and with nothing turned on the battery is then registering ~12.3v. Once charged it does seem good enough to last a couple of days off grid with light use this summer (fridge on setting 3, occasional use of other electrical items etc) but the voltage is approaching 11.9v by the end of the weekend if we've not driven around.

I understand the type of battery to be fitted to the MP to be a AGM battery and therefore the voltage to charge state to be as per the below table (Reference here):

Gel battery voltage
state of charge----Voltage
100%---------------12.80+
75%----------------12.6
50%----------------12.3
40%----------------12.2
25%----------------12
0%-----------------11.8

I'm inclined to believe that at some point prior to me getting the van that the battery was left in a discharge state for a period of time which has partially damaged its performance so it won't ever reach a full charge. Sound familiar to anyone and has anyone been able to convince their dealer that it was their problem to sort out? Or has anyone coughed up for a new battery?

As a related question does anyone know which seat the leisure battery is under for a right hand drive, UK spec van? The manual states the leisure battery is under the drivers seat but all pictures in the manual show a continental left hand drive van. When spinning the passenger seat of my van (UK spec) I can see a battery beneath it with a sticker that says starter battery.

You will see from my earlier post in this thread that your local Mercedes dealer can check the condition of your leisure battery (under the front passenger seat). Their equipment will indicate”replace battery” if it fails certain tests, including its ability to hold charge. They will then replace it under warranty without any argument.

From your description, it looks very much like the problem I had, which was almost certainly down to the selling dealer not carrying out regular charging of the leisure battery. Was your MP a pre-reg like mine, which had been in the showroom for 3 months?

 

[Ian]

You will see from my earlier post in this thread that your local Mercedes dealer can check the condition of your leisure battery (under the front passenger seat). Their equipment will indicate”replace battery” if it fails certain tests, including its ability to hold charge. They will then replace it under warranty without any argument.

From your description, it looks very much like the problem I had, which was almost certainly down to the selling dealer not carrying out regular charging of the leisure battery. Was your MP a pre-reg like mine, which had been in the showroom for 3 months?

Yes ours was a pre-reg model and suspect it went uncharged for quite a long time when it was with the dealer.
My reading of the manual was that the leisure battery was under the front passenger seat, however the label on the top of the battery that I could see when the seat was swiveled round added to the confusion. Thanks for confirming.
I'll speak with the dealer at the same time as getting the airbag cable recall thing sorted.

 

[GeorgeG]

Yes ours was a pre-reg model and suspect it went uncharged for quite a long time when it was with the dealer.
My reading of the manual was that the leisure battery was under the front passenger seat, however the label on the top of the battery that I could see when the seat was swiveled round added to the confusion. Thanks for confirming.
I'll speak with the dealer at the same time as getting the airbag cable recall thing sorted.

The senior technician who replaced the leisure battery on my MP checked both batteries and said they were the same type and capacity AGM battery. I suggest you get both checked to be on the safe side.

 

[Ian]

I got round to taking my MP to the dealer as part of the latest safety recall (re: wires under the swivel seats) and flagged the leisure battery issue to the dealer and stated I expected it to be changed under warranty. They tested it and changed it the next day without any quibbling. Excellent service and although I've not had the chance to test it properly it certainly seems to be registering a much higher voltage (12.8v) after charging.

Leisure Battery Specification:
A 001 982 82 08 (12V, 92Ah, Type: AGM, Size: Length: 353 mm, Width: 175 mm, Height: 190 mm)

 

[GeorgeG]

I got round to taking my MP to the dealer as part of the latest safety recall (re: wires under the swivel seats) and flagged the leisure battery issue to the dealer and stated I expected it to be changed under warranty. They tested it and changed it the next day without any quibbling. Excellent service and although I've not had the chance to test it properly it certainly seems to be registering a much higher voltage (12.8v) after charging.

Leisure Battery Specification:
A 001 982 82 08 (12V, 92Ah, Type: AGM, Size: Length: 353 mm, Width: 175 mm, Height: 190 mm)

Glad you’ve sorted the battery out. Seems to be a fairly common problem with pre-reg vehicles not having the leisure battery regularly charged.

On the question of the recall, I assume this relates to the thorax airbag. I’ve just returned to the UK after 4 weeks away in Canada and I was expecting to find a letter from Mercedes on my doormat inviting me to take my MP to my local dealer to have the wiring problem fixed. Did you receive a letter about this issue? Or maybe not all vehicles are affected.

 

[Ian]

On the question of the recall, I assume this relates to the thorax airbag. I’ve just returned to the UK after 4 weeks away in Canada and I was expecting to find a letter from Mercedes on my doormat inviting me to take my MP to my local dealer to have the wiring problem fixed. Did you receive a letter about this issue? Or maybe not all vehicles are affected.

Yeap I did get a letter from MB recall notice a couple of months ago but only just got around to getting it sorted. It was the recall code SRX1801 (about the thorax airbag cables under the seat getting trapped).

You can see the details on the DFT website here which provides more information on vehicles affected than the letter does.

FYI: The other recall notice which I've been made aware of and got sorted out was SRX1800 and related to the steering column and driver airbag activation.

 

[GeorgeG]

Yeap I did get a letter from MB recall notice a couple of months ago but only just got around to getting it sorted. It was the recall code SRX1801 (about the thorax airbag cables under the seat getting trapped).

You can see the details on the DFT website here which provides more information on vehicles affected than the letter does.

FYI: The other recall notice which I've been made aware of and got sorted out was SRX1800 and related to the steering column and driver airbag activation.

Many thanks for the link Ian. My MP doesn’t seem to be affected by the Thorax air bag issue. I thought it may be affected by missing welding spots issue (SRX1700) as my VIN appears to fall between two of the numbers listed, but the report says it only concerns 3 vehicles, so hopefully I’m wrong.

 

[Richard DL]

Hi really helpful thread. Thanks so far
We bought our MP in Dec 2017 and have used it daily as car and few times as camper for 1/2 night stays. A few weeks back left the car for a while whilst went on holiday. Came back to find none of camper bits worked like pop up roof, fridge, etc. Tried charging through external hook up for 48 hours but nothing !! (Just say at this point I am not very mechanically or electrically savvy!!). Battery showed no signs of life so took to local dealer (didn’t buy MP from there) who checked and agreed needed new battery under near passenger side front seat.

All seemed to work fine but now after about two days fridge turned off again and charge down to 9.0V- warning sign on centre console says battery not charging. Took to another Mercedes van centre - they tightened earth on the new battery but still not working. They also said there are two batteries - one under each front seat? Are they linked ? Do they do same thing? Now driven further over 300 miles and charge still dropping. Anyone know what’s going on - is no charging whilst driving a common problem? I need this fixing soon. Any help greatly appreciated. Thanks in anticipation

 

[GeorgeG]

Richard, when my MP when into my local Mercedes dealer (like you I bought elsewhere) they put it on charge overnight so they could carry out thorough tests the next day. They confirmed that a new leisure battery was required and when I went in to collect the MP the senior technician showed me pages of diagnostic reports. If your local dealer was thorough they should have done the same. If so, any other electrical fault would have shown up. My best guess is that they only tested the battery. If not, it’s very puzzling. Have a word with them and report back.

 

[jeff porter]

where is the leisure battery located please!!

 

[Ian]

The answer is in the thread above but I’ll reconfirm it as being under the front passenger seat (UK model).

 

[Spekky]

I realise that this is an old thread, but I am not sure from the above posts that anyone has fully solved the issue. I, also, cannot charge the leisure battery from the hookup cable. I thought it was working as the bars show the sequential flashing when hooked up, but the voltage stays unchanged. The battery charges fine from the engine. After a couple of weeks not connected, or running, I found the leisure battery so flat that the centre console had gone out. It came on again when I hooked up, but nothing worked, apart from the 220V socket. Not even the floor light under the cupboard. However, all worked once the engine was started and the battery appeared charged after an 80 mile trip.

My question is - has anyone else found that nothing works with the hookup cable attached when the battery is flat and has anyone actually fixed the problem when the battery won't charge from the mains.

 

[Steven rhodes]

Sounds like your 50amp fuse had gone look in the manual and check it,when removed the display goes out it's under a panel on the side of your passenger seat if it's gone I think it will disconnect the leisure battery from your electrical system thus dead display and won't charge I could be wrong but that's my understanding of it

 

[Spekky]

Thanks for the reply Steven.

I have checked the fuse allocation manual and this says there is a 25A fuse in the A pillar of the passenger footwell No. S3 - the "Marco Polo charger, charging connection". However, on my car, there isn't!!!

This might explain why the leisure battery is flat as all I have been charging is fresh air all these times I have been plugging in the hook up cable. Interestingly, when the cable is attached and the rcb turned on, the centre console shows the mains power symbol and the flashing bars for battery charging. Just nothing works apart from the 230V socket.

I'll get the fuse fitted and report back.

 

[Richard DL]

Thanks for the reply Steven.

I have checked the fuse allocation manual and this says there is a 25A fuse in the A pillar of the passenger footwell No. S3 - the "Marco Polo charger, charging connection". However, on my car, there isn't!!!

This might explain why the leisure battery is flat as all I have been charging is fresh air all these times I have been plugging in the hook up cable. Interestingly, when the cable is attached and the rcb turned on, the centre console shows the mains power symbol and the flashing bars for battery charging. Just nothing works apart from the 230V socket.

I'll get the fuse fitted and report back.

 

[PaulE]

Battery woes! Has anyone else had an issue with the leisure battery charging on hook up but appearing not to charge when on the move/through the alternator?