Engine battery draining while traveling, technical help please

[John52]

31 minutes ago, Keithl said:

I totally agree and is why I suspect Phil's ( @Goneoff) MH is not charging.

@John52 is your Fiat current shunt correctly plugged in? If it is then you need to scan your BMS to find out why the EML is on.

Loads to be connected on the chassis side of the sensor yes, but what about secondary batteries?

Rightly or wrongly I connected my secondary batteries on the chassis side of the sensor, rather than the main battery side of the sensor.  Unlike the OP whose secondary batteries appear to be connected on the main battery side of the sensor.

My Ducato dashboard panel says the EML light is on because the start/stop s not working.  Which I assumed to be caused by my secondary bateries as suggested in Derek's link here

I have 2 cheapo code readers - both say 'no codes found'.  But when I erase these non-existant codes with it, the EML light goes out for half an hour or so before coming back on again.

Edited August 25, 2023 by John52

[Keithl]

8 minutes ago, John52 said:

Loads to be connected on the chassis side of the sensor yes, but what about secondary batteries?

ALL connections must be to the chassis side of the shunt. NO connections can made directly to the battery negative terminal

8 minutes ago, John52 said:

My Ducato dashboard panel says the EML light is on because the start/stop s not working.  Which I assumed to be caused by my secondary bateries as suggested in Derek's link here

I have 2 cheapo code readers - both say 'no codes found'.  But when I erase these non-existant codes with it, the EML light goes out for half an hour or so before coming back on again.

A basic code reader will only be able to read generic engine emission faults, you need a code reader capable of reading the codes from your MBS. Something like ECUMultiscan or maybe a Snap On or Autel reader. The code may not even be caused by the BMS???

[onecal]

Hi
Why would these be changed and who would change them? 

10 hours ago, Goneoff said:

To all electrical and technical experts, help and advice required please. 2020 Motorhome on Fiat Ducato 2.3, 160bhp, currently traveling in Europe or trying to. After driving two hours we called to re-fuel with diesel, after we filled up, the motorhome would not start. We then called emergency breakdown (AA equivalent) to get us going. When I checked the engine battery condition, it was in the red and was showing 11.8v on my system. No warning lights were showing on the dashboard. After a hour the battery voltage had risen a small amount, I tried to vehicle and it started. So I was able to drive away from the petrol pump to the carpark where the breakdown guy met us. He checked what the alternator was delivering to the battery and he said it was 11.8v which was far too low however we were able to drive off to a campsite to charge on mains hook-up, by coincidence a Renault mechanic was on site complete with test equipment 👍🏼, after testing he said if he had to chose the between alternator or battery he thought it was the battery that was at fault. So I drove directly to a Fiat Professional garage near Metz; they spent a day testing both, after which they said the smart alternator was functioning perfectly and the battery tested to be fine also; a clean bill of health but a hefty bill for me. But after driving into Germany it happened again when we pulled over for a break after a 2/3 hour drive. The battery was showing 11.2v however after around an hour it had risen enough to start we are now on another campsite and the engine battery is now charged 12.5v. Would appreciate any advice from knowledgeable technical people as to what I should do next apart from jump into the Rhine. 
Sorry it’s a long one. 

 

[Goneoff]

21 hours ago, Keithl said:

I would not recommend unplugging the ECM unless it is absolutely necessary as the pins are small and delicate and easily damaged.

I think we have established the wiring of the DC-DC charger is at fault and are waiting for Phil to come back and say whether he has wiring diagrams.

Thanks for all your help but sadly I don’t have any Burstner wiring diagrams. 
If the system allows I will carry on with our holiday staying on sites with hook-up and on return to the U.K. book it in to Vanbitz and let them check it out. 

[onecal]

Hi
Why would these be changed and who would change them? 

Was there any other work carried out since you brought the motorhome >

Why not disconnect your add on charger to your habitation battery and see if all is normal 

Have you a tow bar fitted ?

On 25/08/2023 at 09:41, Goneoff said:

To all electrical and technical experts, help and advice required please. 2020 Motorhome on Fiat Ducato 2.3, 160bhp, currently traveling in Europe or trying to. After driving two hours we called to re-fuel with diesel, after we filled up, the motorhome would not start. We then called emergency breakdown (AA equivalent) to get us going. When I checked the engine battery condition, it was in the red and was showing 11.8v on my system. No warning lights were showing on the dashboard. After a hour the battery voltage had risen a small amount, I tried to vehicle and it started. So I was able to drive away from the petrol pump to the carpark where the breakdown guy met us. He checked what the alternator was delivering to the battery and he said it was 11.8v which was far too low however we were able to drive off to a campsite to charge on mains hook-up, by coincidence a Renault mechanic was on site complete with test equipment 👍🏼, after testing he said if he had to chose the between alternator or battery he thought it was the battery that was at fault. So I drove directly to a Fiat Professional garage near Metz; they spent a day testing both, after which they said the smart alternator was functioning perfectly and the battery tested to be fine also; a clean bill of health but a hefty bill for me. But after driving into Germany it happened again when we pulled over for a break after a 2/3 hour drive. The battery was showing 11.2v however after around an hour it had risen enough to start we are now on another campsite and the engine battery is now charged 12.5v. Would appreciate any advice from knowledgeable technical people as to what I should do next apart from jump into the Rhine. 
Sorry it’s a long one. 

 

Edited August 26, 2023 by onecal

[Keithl]

4 minutes ago, onecal said:

Why not disconnect your add on charger to your habitation battery and see if all is normal 

Good idea!

@Goneoff If you follow the two brown wires connected to the Negative terminal where do they go? If both go to the DC-DC charger then try removing and insulating them and see what happens.

[John52]

23 hours ago, Keithl said:

ALL connections must be to the chassis side of the shunt. NO connections can made directly to the battery negative terminal

Well in this case thats exactly what they have done.  Made all 4 connections direct to the battery negative terminal.  Which I guess is the cause of the problem.  Because the B2B charger and whatever lights are connected to that Ryder bypass relay in the picture are sharing the current intended for the main battery.  The computer looks at that current sensor and measures what goes in and out of the main battery.  It wouldn't be so bad if it was another battery connected instead of a B2B charger,  If it was another battery it would show current going out when it was in use.  But in the case of the B2B charger it only shows current going in.  So the computer thinks all that current has gone into the main battery and very little has come out, so it must be fully charged.

[david lloyd]

Not wishing to cause more alarm and certainly not sure if this has any relevance to your charging issue but there is a new thread that highlights a recall with KS Energy lithium batteries. Derek has pinned this at the top of the site.

Good luck with resolving your engine battery issue.

David

[onecal]

Hi

To the O.P.

Was there any other work carried out since you brought the motorhome >

Why not disconnect your add on charger to your habitation battery and see if all is normal 

Have you a tow bar fitted ?

Regards

[Goneoff]

Hi thank you for your input and apologies for my late response I’ve been traveling with a draining battery 😩. 
There’s a tow bar on the van that has been recently fitted but not by myself, I believe it was fitted just before I purchased it. Why do you ask? Could the wiring of it be causing the battery to drain?

[Keithl]

19 minutes ago, Goneoff said:

Hi thank you for your input and apologies for my late response I’ve been traveling with a draining battery 😩. 
There’s a tow bar on the van that has been recently fitted but not by myself, I believe it was fitted just before I purchased it. Why do you ask? Could the wiring of it be causing the battery to drain?

No, but whoever fitted it may have moved the brown wires from one side of the shunt to the other ???

[Keithl]

Something to test quickly, unplug the small wires from the Fiat current shunt just behind the Negative terminal. Now start the engine and what happens to the battery voltage?

[onecal]

Hi

I think you may have found your problem 

Regards

[John52]

3 hours ago, Keithl said:

No, but whoever fitted it may have moved the brown wires from one side of the shunt to the other ???

Its not a shunt its a current sensor (Hall effect)

(I can see it more clearly than you because I've seen the thing itself on my identical Ducato, rather than the photograph.)

And yes, I agree, I think all 4 wires (brown and white) should be on the other side of it.

The instructions probably say 'connect direct to battery' (for minimum electrical resistance)- not accounting for smart alternators and current sensor

If it was mine I would move them to the other side of the current sensor, having first followed the procedure for disconnecting the battery. (shut all the doors and wait a minute for the body computer to shut down)  You can then disconnect the battery lead until you have moved the connections to the terminal on the other side of the sensor

PS: or if you can't get them all on the sensor terminal, direct to body earth.  Sensor terminal would just be preferable because then they all disconnect when you unclip the main earth lead.

Edited August 28, 2023 by John52

[Alanb]

3 hours ago, Keithl said:

No, but whoever fitted it may have moved the brown wires from one side of the shunt to the other ???

On our Saab 9-3, which has a similar "shunt" on the battery negative and diagonally bolted battery terminal clamps, the clamping bolt is M6 (10mm spanner), but the main current terminal, where the short earth connection is attached, is M8 (13mm spanner).  I note that M10 has been mentioned in an earlier post.

If the brown cables have been moved on @Goneoff's vehicle, then it is most likely that the original crimped cable terminations have been retained.  These terminals will be oversize for the clamping bolt, and this may be apparent on visual inspection.  So a possible confirmation that the cables have been moved?

Alan

Edit:  I agree with John's post above, however I have used the term "shunt" in inverted commas, since it is more widely understood, as a current sensing device.

 

Edited August 28, 2023 by Alanb

[John52]

In this case both terminals have 10mm nuts so the cables will fit on one side as well as the other

Its Mopar part number 52087078 so you can google it for a pic eg

Its described as an IBS - 'Intelligent Battery Sensor'

Edited August 28, 2023 by John52

[Alanb]

31 minutes ago, John52 said:

In this case both terminals have 10mm nuts so the cables will fit on one side as well as the other

Its Mopar part number 52087078 so you can google it for a pic eg

Its described as an IBS - 'Intelligent Battery Sensor'

Thanks for the part number.  Good picture on Ebay.  Take care of yours, used price from Lithuania including delivery £68.40.

[Goneoff]

Hi Keith, John, Alan. 
I’m now on a site in Italy so could try some of the things you suggest. 
see attached pic; do you mean I should try moving the four wires circled in red to where I have indicated? 
Let me know. 
Thanks all you guys for helping. 

[John52]

29 minutes ago, Goneoff said:

Hi Keith, John, Alan. 
I’m now on a site in Italy so could try some of the things you suggest. 
see attached pic; do you mean I should try moving the four wires circled in red to where I have indicated? 
Let me know. 
Thanks all you guys for helping. 

Yes, thats it exactly

Shut all doors and wait one minute for the body computer to shut down

Unclip the battery earth lead (just press in the grey button in your pic to release the connector)

Then change them over

Reconnect earth lead

You will need the radio code to reset the radio, and reset the time on the dashboard display as in the handbook

Press 'mode' scroll through to date etc, and use the arrow buttons to set it.

Edited August 28, 2023 by John52

[Robinhood]

I'd likely agree with the potential diagnosis you've been given, but  the lack of clarity of the picture means I'm not certain, and also not certain that the move you describe is the correct one. (The picture isn't clear enough for me at least to identify the components).

So, back to basics. Your vehicle is likely fitted with a smart alternator. This is controlled by measurement and logic in regards to the total capacity input to and output from the vehicle battery. The measurement of this is via a "shunt" connected between the negative terminal of the battery and the vehicle ground (the body). For proper functioning it is essential that all current flow (either in or out) is measured and calculated. This means there should be no additional earth connection on the battery side of the shunt.

If another earth connection is present on the battery side of the shunt, then any current flowing in the circuit it supports won't be monitored. There are a couple of hefty connections (and a few others) in your picture that appear to be directly connected. My suspicion would be that the thicker is for split charge/B2B, and this will potentially take a lot of capacity from the vehicle battery circuit which is unmeasured. This means any smart alternator would be unaware, and you would end up with pretty poor charging (if any) whilst driving.

Now, I haven't a reference for a Ducato "shunt", and the topology of the connections isn't clear. That means that I'm not entirely sure that the additional connections are on the wrong side of the shunt, and if they are I'm not sure the new connection point you circle is correct. This latter is largely because the shunts I've seen look more like the unit (with letters on) to the left of the arrowhead.

Others may be better placed to advise in detail, but the fundamentals are:

a) one side of the shunt should connect to the battery negative terminal

b) there should be no ground connection on that side of the shunt

c) the other side of the shunt should be grounded to the body (hefty cable), and all additional grounds should be on this side of the shunt.

The things that concern me are:

a) just exactly where is the negative terminal connection

b) just exactly what is the red-ringed multi connection bolted to (can't see where)  

c) if the box with writing on is the shunt, is the other black unit a negative disconnection relay (with the original ground cable to the left?).  

Edit to add:

John's clarified the second point c) above.

If the second b) above answer is that it is connected directly to the negative terminal, then the move you've described is probably good. 

 

 

Edited August 28, 2023 by Robinhood

[John52]

20 minutes ago, Robinhood said:

 

John's clarified the second point c) above.

If the second b) above answer is that it is connected directly to the negative terminal, then the move you've described is probably good. 

 

 

Yes it is - so he is effectively moving those 4 wires from the battery negative terminal, to body ground - the other side of the sensor, via the O/E battery earth cable

[Goneoff]

I was hoping to post a positive response for you guys but unfortunately I don’t have the Pioneer radio code with me which I use primarily as a satnav, however I’m hoping my daughter can find it and send a pic tomorrow. If she can’t find it I will still go ahead anyway and switch the wires around although I guess without my multi meter I will not be able to test the outcome until we drive off to our next location. 

Will report back as soon as I can. 

Thanks again 

[Alanb]

Cannot the battery monitoring app, be used to observe battery voltage as before?

I am in general agreement with John as regards the need to move the wires/cables from the clamping bolt (battery terminal) to the other side of the current sensor or "shunt".

Subject to the radio code being available, for the immediate short term I support proceeding as proposed.

For the longer term, perhaps extend all four connections to the main earth point?  This is because with both the present and proposed connections, the battery disconnecting device alluded to by John "Unclip the battery earth lead,,,,," is not effective for the four connections being discussed.

Better to have a disconnecting device that functions as intended.

Perhaps I am being too much of a "Jonah", but I spent my working career in enviroments where the guiding principle could be stated as "If it can go wrong, it will.".

Alan

[Keithl]

As you do not have the code to reset the radio try unplugging the small wires from the sensor. This should put the BMS into a default condition of maximum charging. This will at least identify if moving the wires will fix your issue.

[onecal]

Hi Goneoff,

As Keithl has posted it should indeed put the BMS into default condition . This will indeed clarify the issue?