Goneoff Posted August 25, 2023 Share Posted August 25, 2023 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. Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 @Goneoff A bit of back story may help here please... How long have you owned the MH and has this problem suddenly appeared or been evident for a while, maybe not so pronounced as now, eg slow cranking? Is your MH a commercially available model, from a smaller converter or maybe self-build? What split charge system do you have fitted? eg simple split charge relay, B2B, etc. Do you have solar installed, this may explain the starter battery voltage rising while you waited for recovery. What type of fridge do you have fitted, compressor or absorption, and do you know how it is wired? Finally can you monitor either starter or leisure battery voltage while driving? Keith. Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 I have a Dec2020 manufactured 2.3 Ducato 140 with the 'Smart Alternator' 4 x 019 Varta batteries connected in parallel through a split charge relay, and voltmeters on both circuits A couple of months ago I found the engine battery was not holding its charge as well as the others so I replaced it. Said Engine battery is an O/E Varta Stop/Start battery dated 3220 (week 32 year 2020). I replaced it with a standard Varta battery https://www.tayna.co.uk/car-batteries/varta/i1/ which is holding its charge perfectly. Quote Link to comment Share on other sites More sharing options...
Labby Posted August 25, 2023 Share Posted August 25, 2023 It would be worth checking the alternator main output cable for corrosion/ poor connection at its connection to the alternator and main battery positive cable at the starter battery. Also , in case the engine/gearbox to body earth cable is faulty , it would be worth replacing it (or adding another) as a problem with this cable can also cause poor charging . (internal corrosion between the cable and its terminal causing a resistance) Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 On top of the battery is a current sensor which the smart charging system uses to determine (perhaps wrongly especially if the battery is faulty) the battery state of charge. Unplugging that should cause the alternator to charge normally. Unfortunately its also likely to bring on the engine management light (MOT fail) as the Start Stop is no longer working because the computer can't calculate the battery state of charge. But at least it would keep the battery charged till you get home Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 1 hour ago, Keithl said: @Goneoff A bit of back story may help here please... How long have you owned the MH and has this problem suddenly appeared or been evident for a while, maybe not so pronounced as now, eg slow cranking? Is your MH a commercially available model, from a smaller converter or maybe self-build? What split charge system do you have fitted? eg simple split charge relay, B2B, etc. Do you have solar installed, this may explain the starter battery voltage rising while you waited for recovery. What type of fridge do you have fitted, compressor or absorption, and do you know how it is wired? Finally can you monitor either starter or leisure battery voltage while driving? Keith. Thanks for your response Keith. Purchased end of June this year, Burstner ixeo 680 g, first Reg Sept 2020. Can’t honestly say it’s an old issue it maybe but I think it’s a new manifestation. No slow cranking at all, no dimming of the lights on the dashboard, even when the engine battery isn’t fully charged. The vehicle has start stop technology which I have turned off. Simple split charge B2B I will attach pic of battery. Very small solar which I understand charges the lithium hab battery which is installed. Fridge: 3 way Dometic absorption fridge no idea how it’s wired. Re battery monitoring: Not really while driving but can see engine battery on Phantom tracker online monitor. Can see KS Energy lithium hab battery on their app Phil Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 18 minutes ago, John52 said: On top of the battery is a current sensor which the smart charging system uses to determine (perhaps wrongly especially if the battery is faulty) the battery state of charge. Unplugging that should cause the alternator to charge normally. Unfortunately its also likely to bring on the engine management light (MOT fail) as the Start Stop is no longer working because the computer can't calculate the battery state of charge. But at least it would keep the battery charged till you get home Hi John thanks for the info I’ve attached a couple of pics of the battery could you advise what I should unplug from the pics or better still mark it up. Thank you Phil Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 52 minutes ago, Labby said: It would be worth checking the alternator main output cable for corrosion/ poor connection at its connection to the alternator and main battery positive cable at the starter battery. Also , in case the engine/gearbox to body earth cable is faulty , it would be worth replacing it (or adding another) as a problem with this cable can also cause poor charging . (internal corrosion between the cable and its terminal causing a resistance) Thanks but it all looks sound Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 1 hour ago, John52 said: I have a Dec2020 manufactured 2.3 Ducato 140 with the 'Smart Alternator' 4 x 019 Varta batteries connected in parallel through a split charge relay, and voltmeters on both circuits A couple of months ago I found the engine battery was not holding its charge as well as the others so I replaced it. Said Engine battery is an O/E Varta Stop/Start battery dated 3220 (week 32 year 2020). I replaced it with a standard Varta battery https://www.tayna.co.uk/car-batteries/varta/i1/ which is holding its charge perfectly. Thanks for the response, I’m actually thinking of doing the same, that is having a new battery installed, purely to eliminate the battery as an issue. It’s an expensive elimination but I’m not in the best position right now. Did you fit the battery yourself? Thanks Phil Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 Phil, The 'Ryder TF ...' box looks like a trailer light module so is unlikely to be your problem. My thoughts are that your starter battery is NOT being charged by your alternator but your DC-DC charger is still trying to charge your leisure battery from your starter battery hence draining the starter battery. Does your Phantom app show live voltage reading or can you get a multimeter and measure the starter battery voltage with the engine running? Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 29 minutes ago, Keithl said: Phil, The 'Ryder TF ...' box looks like a trailer light module so is unlikely to be your problem. My thoughts are that your starter battery is NOT being charged by your alternator but your DC-DC charger is still trying to charge your leisure battery from your starter battery hence draining the starter battery. Does your Phantom app show live voltage reading or can you get a multimeter and measure the starter battery voltage with the engine running? Hi Keith unfortunately haven’t got my multi-meter with me but I have attached screenshots of Phantom monitor; 30 days, 7 days and 3 days which may help you diagnose the issue. As you can see clearly on the 3 day pic that I’m on hook-up and all looks well but I know it isn’t although it will allow me to travel to another site. Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 From those graphs the underlying battery voltage is definitely falling over the 30 day period but that may simply due to the fact it is not being fully recharged. What the graphs do show me is that the alternator is NOT reliably recharging the starter battery, only occasionally peaking at over 13 volts and certainly not for any sustained length of time. As you do not know how long this problem has been occurring it could be for one of two reasons... First the DC-DC setup is not compatible with your smart alternator system and is drawing power from the starter battery rather than the alternator as the alternator is not aware of its presence, or... Second, your smart alternator system has failed and is not charging either battery. More detailed investigation is required to ascertain your true fault. And I suspect if you did fit a new starter battery it would suffer the same fate in a short time. Quote Link to comment Share on other sites More sharing options...
Alanb Posted August 25, 2023 Share Posted August 25, 2023 (edited) I agree with Keith that there is insufficient voltage at the battery, for it to receive any significant charge. The following is only tentative, and I would appreciate the comments of others. Building from Keith's post above, and examining the photos of the battery negative connections, it seems that there is a shunt connected to the negative terminal. This would allow the smart alternator system to monitor the battery current. However there are also two brown cables and others connected at this point. I take thes brown cables to be for the habitation electrics, and the associated B2B charger. These cables appear to be attached to the battery terninal clamping bolt, and not to the chassis side of the shunt. If this is so, the the smart alternator system will see the B2B current and what the other brown cable is supplying as battery charge current. Should not these additional cables be connected to the chassis side of the shunt, and not directly to the battery negative? Alan Edited August 25, 2023 by Alanb 1 Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 4 minutes ago, Alanb said: The followi is only tentative, and I would welcome the comments of others. I agree with Keith that there is insufficient voltage at the battery, for it to receive any significant charge. Building from Keith's post above, and examining the photos of the battery negative connections, it seems that there is a shunt connected to the negative terminal. This would allow the smart alternator system to monitor the battery current. However there are also two brown cables and others connected at this point. I take thes brown cables to be for the habitation electrics, and the associated B2B charger. These cables appear to be attached to the battery terninal clamping bolt, and not to the chassis side of the shunt. If this is so, the the smart alternator system will see the B2B current and what the other brown cable is supplying as battery charge current. Should not these additional cables be connected to the chassis side of the shunt, and not directly to the battery negative? Alan Hi Alan, thanks for your input, it may well be that the system is incorrectly wired but I’m afraid my knowledge of how it should look is limited; I probably know more about rocket science than how my electrical system should look like at the battery, hopefully someone will come along and clarify. Regards Phil Quote Link to comment Share on other sites More sharing options...
onecal Posted August 25, 2023 Share Posted August 25, 2023 Hi Disconnect your battery , Check the wiring at the ECU by releasing and reconnecting a few times Re connect your battery and re try to see if it improves . Hope this simple trick helps Regards Quote Link to comment Share on other sites More sharing options...
Alanb Posted August 25, 2023 Share Posted August 25, 2023 34 minutes ago, Goneoff said: Hi Alan, thanks for your input, it may well be that the system is incorrectly wired but I’m afraid my knowledge of how it should look is limited; I probably know more about rocket science than how my electrical system should look like at the battery, hopefully someone will come along and clarify. Regards Phil Phil, OK but can you confirm that the original device clamped to the battery negative post, has two small wires attached, at separate points, and not where the brown cables are attached? Alan Quote Link to comment Share on other sites More sharing options...
Goneoff Posted August 25, 2023 Author Share Posted August 25, 2023 1 hour ago, onecal said: Hi Disconnect your battery , Check the wiring at the ECU by releasing and reconnecting a few times Re connect your battery and re try to see if it improves . Hope this simple trick helps Regards Cheers will give it a try Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 2 hours ago, Alanb said: However there are also two brown cables and others connected at this point. I take thes brown cables to be for the habitation electrics, and the associated B2B charger. These cables appear to be attached to the battery terninal clamping bolt, and not to the chassis side of the shunt. If this is so, the the smart alternator system will see the B2B current and what the other brown cable is supplying as battery charge current. Should not these additional cables be connected to the chassis side of the shunt, and not directly to the battery negative? Alan From a quick search I am going to agree with Alan that your brown wires are incorrectly connected to the wrong end of the BMS shunt. Looking at the Victron energy website https://www.victronenergy.com/media/pg/SmartShunt/en/installation.html it clearly states... "Connect the negative battery terminal to the M10 bolt on the "BATTERY MINUS" side of the shunt. Note that there should be no other connections on this side of the shunt or on the negative battery terminal." As you bought the MH second hand you have no way of knowing if a previous owner changed the position of the wiring when maybe replacing the battery or having the trailer light wiring added. Do you have a Burstner wiring diagram in your Owners handbook or could you contact Burstner to ask where these wires should be connected? Failing this to will need the services of an auto electrician familiar with the Ducato BMS and additional wiring. Keith. 1 Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 3 hours ago, onecal said: Hi Disconnect your battery , Check the wiring at the ECU by releasing and reconnecting a few times Re connect your battery and re try to see if it improves . Hope this simple trick helps Regards Be careful!! There is a procedure detailed in the handbook for disconnecting the battery Basically switch the ignition off, close all doors, and wait 60 seconds This gives the body computer time to shut down before you disconnect the power Otherwise its like pulling the plug out of a PC when its running!! Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 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. Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 5 hours ago, Goneoff said: Hi John thanks for the info I’ve attached a couple of pics of the battery could you advise what I should unplug from the pics or better still mark it up. Thank you Phil If you look at the little black box bolted on to the negative battery terminal you see a plug in the end of it with a couple of thin wires. Just squeeze the end of that plug where the wires go in so you can pull the plug out. Or some people just take out the fuse that supplies it with power. If you look in the fuse box in front the driver's knee there is 3 horizontal rows. The fuse is in the centre row, furthest one to the left - 7.5A. Either of these things should cause the system to default to charging like an ordinary alternator. But unfortunately may cause the engine management light to come on to say the start stop is not working (as the computer can no longer calculate whats in the battery) In which case the engine management lightmay stay on when you put the plug or fuse back until you clear the fault codes - which you can do with a cheapo code reader. You really need a voltmeter you can see when you are driving to check a smart alternator. Because it might only work when you are going downhill and in gear with your foot off the throttle. You could be sitting on tickover and the battery actually discharging if its just been fully charged with regenerative braking. I got a voltmeter off ebay you plug in the cigar lighter - only a couple of quid Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 I have one of these (click link) which fits in the cigar lighter so you can see it from the driver's seat Quote Link to comment Share on other sites More sharing options...
John52 Posted August 25, 2023 Share Posted August 25, 2023 19 minutes ago, Keithl said: 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. I don't know. I wondered which side of that current sensor I should wire my secondary batteries to. In the event I wired them direct to body earth - so the secondary battery current is not going through the current sensor because I didn't want to slow down the charge rate. As it is the 510ah battery bank goes over 15 volts with regenerative braking. It all works fine except for bringing on the engine management light to say the start stop is not working (MOT fail) But I can get round this by disconnecting the secondary batteries through my dashboard switch, and clearing the fault codes to get it through the MOT. Would be nice to extinguish the engine management light all the time though. I might try wiring the secondary batteries to the main battery side of the current sensor like in Paul's diagram. Not a quick job though because I have to take the seats out to get to the batteries underneath. Quote Link to comment Share on other sites More sharing options...
Alanb Posted August 25, 2023 Share Posted August 25, 2023 6 hours ago, John52 said: On top of the battery is a current sensor which the smart charging system uses to determine (perhaps wrongly especially if the battery is faulty) the battery state of charge. Unplugging that should cause the alternator to charge normally. Unfortunately its also likely to bring on the engine management light (MOT fail) as the Start Stop is no longer working because the computer can't calculate the battery state of charge. But at least it would keep the battery charged till you get home John52, Sorry, I missed your post above when scanning the thread. I think that you have raised this before, perhaps on another forum, or is my memory playing tricks? In my opinion, any loads should be connected on the chassis side of the shunt/sensor, probably a Hall effect device. This is what happens with the base vehicle electrics e.g. lights, wipers, heater fan, ECU etc. Alan Quote Link to comment Share on other sites More sharing options...
Keithl Posted August 25, 2023 Share Posted August 25, 2023 5 minutes ago, Alanb said: In my opinion, any loads should be connected on the chassis side of the shunt/sensor, probably a Hall effect device. This is what happens with the base vehicle electrics e.g. lights, wipers, heater fan, ECU etc. Alan 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. Quote Link to comment Share on other sites More sharing options...
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