Riddle me this.....starter battery problem solves itself.

They were original equipment from Adria for the leisure battery when we bought the van LennyHB
 
Russell's Dad said:
I initially thought the solenoid might be the problem ( I'd read about this) , I even thumped the starter motor with a rubber mallet to see if that fixed the problem, but it doesn't really explain why the battery didnt appear to be taking a charge from the alternator. When accelerating (i.e. when putting the engine under strain) the battery was only showing 12.1 to 12.4v, while the leisure batteries were full. Decelerating/ braking showed 13.8 -14.2v or thereabouts was getting to the battery from the alternator, similarly when the solar switched to the starter battery (PV Logic controller so it swaps from leisure to starter regularly with no way to manually control this) the voltage was there to charge but it just didn't seem to take or hold the charge.

Switching off the ignition used to cause a slight drop in voltage to show, but this quickly returned to 12.8v ish. Normally after a drive the starter battery would show as full in the app. When I had the non-starting problems the voltage dropped and didn't come back up until the solar did it's thing. The battery kept it's charge overnight as well.

The van started with a jump start, but I suppose that might have been after the solenoid had cooled.

Also, after the battery re-fit, when all seemed back to normal with charging etc, I stopped at services. The van was hot after a hundred or so motorway miles, but it started no problem.

Would the solenoid going open circuit cause the battery to discharge heavily when driving?

Could it be a mix of bad earth and solenoid???

I know that using the app to check voltage isn't scientific as it just shows what is reaching the bsttery terminsls in both directions, but the app had previously never shown a voltage of 12.1 v at the starter battery.

In saying all that, I might get the solenoid tested or replaced just as a belt and braces.

When I can, I'll post an update.
Click to expand...
The starter battery voltages you have found are right for a smart alternator and I think could be sending you down a blind alley. The system is usually designed to stop charging around 85 to 90% capacity so the overrun charging (regen) has somewhere to go.
The earth test is very easy with a jump lead but if I understand correctly every non start recovery involved a rest time of 20 minutes plus after the interventions?
The starter solenoid issue is not easy to prove consistently but I have seen it so many times and usually because the connections rotated slightly when being wired up. Unfortunately modern electrical equipment is not bench tested anymore before packing and contactors especially seem to not have the inner nuts torqued at all during manufacture.
 
Bad connection. Checkchassis to battery and engine to chassis bonding braids. Check main connections to starter motor solenoid.
None of the voltages stated (if they are for the starter battery) suggest the battery is charging at that moment, however they should all be sufficient to start the engine. It needs looking at.
Have seen similar before and it was that the bonding point on the chassis had rusted out.

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Russell's Dad said:
Ducato 2021, 2.3 150bhp 9 speed auto Carthago i138. Smart alternator. 150w solar charging both starter and leisure batteries.
In France on an Aire in the middle of nowhere. I stopped the engine and went to get the ramps. Tried to start the engine and...click. Tried a few times, same result. Checked the solar controller app and starter battery is at 12.1v. It was a sunny day. 10 minutes later and I try again and success, the starter engages and the engine starts.
All is well for the next couple of weeks, except I check the solar app regularly and can clearly see the starter battery is getting charge from the solar and, when driving, from the smart alternator, but isn't keeping the charge. When driving the starter battery is often about 12.2-12.4v when not getting a charge from solar or the alternator ( i.e. cruising or accelerating, not engine braking or braking). It's almost as if the alternator thinks the battery is at capacity, so isn't trying to charge it all the time.
The weather was good and I was parking up mid afternoons with the voltage on switching off being 12.1 to 12.3v and 12.8 ish at night when solar charging stopped. In the mornings the engine started OK so I decided to nurse it back to the UK.

Fast forward to this morning when, after Le Shuttle and a few hours of motorway driving back in the UK I stop at services for 10 minutes and the van won't start. Click.....solar app shows 12.2v. Handily I have a lithium jump-start gizmo so I use that and the van fires up.
Off I go to Halfords for a new battery. The helpful fellow ( he really was a nice bloke) removes the old battery and checks if they have a like-for-like replacement, which they unfortunately don't. The nearest likeness is fitted, but doesn't have the same cranking power. The van won't start ( same click).
The old battery is refitted so I can jump start and try to get back to Scotland. The van starts at the first turn of the key, without the jumper pack. A check of the solar app shows the battery is now consistently getting a good charge from the alternator, even while stationary. Continued checking of the app shows the battery is now accepting charge ( dark so no solar) and the smart alternator is now doing exactly what it should do, i.e. stopping providing 14v charge when the battery is at capacity.
In short, removing the battery and then putting it back appears to have resolved the problem. The smart alternator is doing it's job, the battery is accepting and keeping the charge. Switching off the ignition on arriving at home the battery showed 12.75 rising quickly to 12.85.

My question( only to the technically profficient Fun members please) is simply this. What has happened? Was a battery "re-boot" enough to fix the problem or do I have a wiring problem such as a loose wire at the battery that has miraculously re-attached during the battery swap. If so then what wire is the likely culprit?
Click to expand...
Sounds like either a dodgy battery connection or a bad earth. Used to get it all the time on my tractor.
 
Bad battery connection. I’ve just had this exact issue whilst away in Scotland. Symptoms sound identical. When I took the battery cover off it seemed to cure itself for a while then did it again. I then undid the earth strap wire and power wire, wire brushed every connection, put it all back together and it’s been fine ever since. I did tap the positive clamp further onto the post too.
 
This is the same problem I have on my 2021 160 Carthago..
Fitted with a smart alternator..
The Smart alternator is not so smart.😪.
My starter motor is trickle charged while on Solar, to full.
When I start the van at home the 3 way fridge kicks in for the journey.
Because it is a smart alternator it has a 25amp B to B charger which draws current from the Starter Battery as designed .
So you now have a 25 amp draw on the starter Battery, my starter battery falls below 12 v ..
With no load it seems to be 12.2 v set by fiat which is madness as most smart alternators on cars I work on are set at 12.8-13 volts ,this at least means the battery will maintain a charge of 80,%..
What I find is when driving the battery is gradually discharged as the smart alternator only charges on the over run not while cruising,idling .
After an hour of curing to the new forest my starter battery is now lower voltage than when I left.
Invariably around 12.5-12.6 volts.

With regards to the failure to start I also have the same problem ,a few times two years ago when the van was new,then two weeks ago.The battery voltage was showing 12.1 and the starter clicked as a flat battery, yet all lights fan etc was working...
Over a period of 5-10 minutes it failed to start,luckily it was in the carpark of a service station.Then it started perfectly and Instantly, THIS IS NOT A BATTERY VOLTAGE problem.
The main earth lead connection on the new Fiat's is a crazy push on swivelling connection,absolute madness in my view, I have made and terminated a proper earth lead.fitted alongside the Fiat earth .
Since the failure to start was RARE, I can't say for sure if the problem is cured, but the Fiat earth lead system seems to be poor in my view as a mechanic.
Lastly when you removed the battery and replaced it back with the old one the alternator started charging as you would Expect as you observed.
The Smart alternator is controlled by the Battery Management System ,this is a device fitted to the negative of the Starter battery connected by 2wires , this feeds info to the ECU that controls the Smart Alternator.
When you remove the negative terminal or the 2wire connector and reconnect the smart altery seems to INITIALLY charge at full current as a learning process , but my observation of voltage days after show the low set voltage of 12.2.
I have wondered about heat soak to the Starter this is a pissibily as one time failure to start was when queued in traffic ,but the last time was after a short cruising journey.
I think there is definitely a problem here as some suggested the trickle feed from the hab batteries in the motorhome system to the starter may upset the BMS ,Likewise the solar feeding the hab batteries raise the voltage which then gets trickled to the starter battery.
The BMS would never see these on a normal Commercial van .
Having said that I feel a set voltage of 12.2 v is far too low .
The fiat swivelling earth lead system is a poor design
The trickle feed to the starter battery may well upset the BMS and cause further issues.
To sum up the SMART ALTERNATOR SYSTEM is not so smart...😪
 
The weird swilling earth system

Screenshot_20231008-142455.png
 
NASHMAN600 said:
This is the same problem I have on my 2021 160 Carthago..
Fitted with a smart alternator..
The Smart alternator is not so smart.😪.
My starter motor is trickle charged while on Solar, to full.
When I start the van at home the 3 way fridge kicks in for the journey.
Because it is a smart alternator it has a 25amp B to B charger which draws current from the Starter Battery as designed .
So you now have a 25 amp draw on the starter Battery, my starter battery falls below 12 v ..
With no load it seems to be 12.2 v set by fiat which is madness as most smart alternators on cars I work on are set at 12.8-13 volts ,this at least means the battery will maintain a charge of 80,%..
What I find is when driving the battery is gradually discharged as the smart alternator only charges on the over run not while cruising,idling .
After an hour of curing to the new forest my starter battery is now lower voltage than when I left.
Invariably around 12.5-12.6 volts.

With regards to the failure to start I also have the same problem ,a few times two years ago when the van was new,then two weeks ago.The battery voltage was showing 12.1 and the starter clicked as a flat battery, yet all lights fan etc was working...
Over a period of 5-10 minutes it failed to start,luckily it was in the carpark of a service station.Then it started perfectly and Instantly, THIS IS NOT A BATTERY VOLTAGE problem.
The main earth lead connection on the new Fiat's is a crazy push on swivelling connection,absolute madness in my view, I have made and terminated a proper earth lead.fitted alongside the Fiat earth .
Since the failure to start was RARE, I can't say for sure if the problem is cured, but the Fiat earth lead system seems to be poor in my view as a mechanic.
Lastly when you removed the battery and replaced it back with the old one the alternator started charging as you would Expect as you observed.
The Smart alternator is controlled by the Battery Management System ,this is a device fitted to the negative of the Starter battery connected by 2wires , this feeds info to the ECU that controls the Smart Alternator.
When you remove the negative terminal or the 2wire connector and reconnect the smart altery seems to INITIALLY charge at full current as a learning process , but my observation of voltage days after show the low set voltage of 12.2.
I have wondered about heat soak to the Starter this is a pissibily as one time failure to start was when queued in traffic ,but the last time was after a short cruising journey.
I think there is definitely a problem here as some suggested the trickle feed from the hab batteries in the motorhome system to the starter may upset the BMS ,Likewise the solar feeding the hab batteries raise the voltage which then gets trickled to the starter battery.
The BMS would never see these on a normal Commercial van .
Having said that I feel a set voltage of 12.2 v is far too low .
The fiat swivelling earth lead system is a poor design
The trickle feed to the starter battery may well upset the BMS and cause further issues.
To sum up the SMART ALTERNATOR SYSTEM is not so smart...😪
Click to expand...
That all makes perfect sense, although I thought the b2b and fridge power draw would cause the alternator to kick in to charge the starter battery, even when the engine is under load/cruising?? Is it not the case that the alternator should provide charge when required ( as opposed to all time as ordinary alternators do)?
I also had a look at the swivelling earth fitting and think it is pants. I roughed up both the male and the female bits. I started the van this morning and the voltage dropped as you would expect but no charge came from the alternator. From what you have said this might be normal?

I'm going to get the starter solenoid replaced and all the main earth's checked. Hopefully that will stop it from happening again.

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Just to add. I always turn off Stop/Start as it sometimes causes the head unit to reboot on starting.
I'm glad the van didn't fail to start in traffic.
 
So I cant answer your Fiat question I can tell you how the VW battery management system (BCM) works - we had a golf and the battery was failing, it was slow to crank and only just catching so I went out and bought a new battery and found out the new battery had to be coded to the car.

A good friend is a van technician in a VW van dealership so i thought I’d get him to sort the programming for me with their diagnostic kit - a phone call later he tells me to charge the old battery with the charger connected to the battery posts and nowhere else.

This was done and it was like a new battery on there which is still going strong today (& the new one went back)

It seems that the BCM module sits between the battery and the rest of the vehicle, (it decides amongst other things) what charge gets to the battery - it seems that the battery voltage slips over time and the BCM thinks its fully charged when it’s not.

I’m guessing that the Fiat system works in a similar manner and that any solar or mains hook up connection to the starter battery goes through a battery management system so it might be worth putting a proper battery charger on the battery terminals before you spend any money.
 
Russell's Dad said:
Ducato 2021, 2.3 150bhp 9 speed auto Carthago i138. Smart alternator. 150w solar charging both starter and leisure batteries.
In France on an Aire in the middle of nowhere. I stopped the engine and went to get the ramps. Tried to start the engine and...click. Tried a few times, same result. Checked the solar controller app and starter battery is at 12.1v. It was a sunny day. 10 minutes later and I try again and success, the starter engages and the engine starts.
All is well for the next couple of weeks, except I check the solar app regularly and can clearly see the starter battery is getting charge from the solar and, when driving, from the smart alternator, but isn't keeping the charge. When driving the starter battery is often about 12.2-12.4v when not getting a charge from solar or the alternator ( i.e. cruising or accelerating, not engine braking or braking). It's almost as if the alternator thinks the battery is at capacity, so isn't trying to charge it all the time.
The weather was good and I was parking up mid afternoons with the voltage on switching off being 12.1 to 12.3v and 12.8 ish at night when solar charging stopped. In the mornings the engine started OK so I decided to nurse it back to the UK.

Fast forward to this morning when, after Le Shuttle and a few hours of motorway driving back in the UK I stop at services for 10 minutes and the van won't start. Click.....solar app shows 12.2v. Handily I have a lithium jump-start gizmo so I use that and the van fires up.
Off I go to Halfords for a new battery. The helpful fellow ( he really was a nice bloke) removes the old battery and checks if they have a like-for-like replacement, which they unfortunately don't. The nearest likeness is fitted, but doesn't have the same cranking power. The van won't start ( same click).
The old battery is refitted so I can jump start and try to get back to Scotland. The van starts at the first turn of the key, without the jumper pack. A check of the solar app shows the battery is now consistently getting a good charge from the alternator, even while stationary. Continued checking of the app shows the battery is now accepting charge ( dark so no solar) and the smart alternator is now doing exactly what it should do, i.e. stopping providing 14v charge when the battery is at capacity.
In short, removing the battery and then putting it back appears to have resolved the problem. The smart alternator is doing it's job, the battery is accepting and keeping the charge. Switching off the ignition on arriving at home the battery showed 12.75 rising quickly to 12.85.

My question( only to the technically profficient Fun members please) is simply this. What has happened? Was a battery "re-boot" enough to fix the problem or do I have a wiring problem such as a loose wire at the battery that has miraculously re-attached during the battery swap. If so then what wire is the likely culprit?
Click to expand...
Starter solenoid playing up is the usual cause of a click but not turning over the engine often due to a bad earth or too low a voltage at the solenoid
 
Russell's Dad said:
That all makes perfect sense, although I thought the b2b and fridge power draw would cause the alternator to kick in to charge the starter battery, even when the engine is under load/cruising?? Is it not the case that the alternator should provide charge when required ( as opposed to all time as ordinary alternators do)?
Click to expand...
That is not how it works.

The B2B will work at whatever voltage is being output by the not-so-smart alternator.
The alternator is always providing 'power' - it is the voltage which changes.

The B2B will work at the low voltage, whereas battery charging does not.
The B2B constantly outputs a higher voltage the that the leisure battery charges.
 
LostInSpace said:
That is not how it works.

The B2B will work at whatever voltage is being output by the not-so-smart alternator.
The alternator is always providing 'power' - it is the voltage which changes.

The B2B will work at the low voltage, whereas battery charging does not.
The B2B constantly outputs a higher voltage the that the leisure battery charges.
Click to expand...
No voltage = no power.

The smart alternator leaves room in the engine battery for energy recovery when slowing down. It achieves this by monitoring the engine battery voltage. When the alternator voltage drops no power flows into the battery and the engine load is reduced saving you fuel. When you brake energy is wasted but at this point the smart alternator voltage rises and power (Amps) flows into the battery, the engine braking increases because the alternator is suddenly working very hard. In other words the smart alternator works extra hard when you don’t need engine power and when engine power is needed it cuts out. I think that is smart. A heavy duty alternator can be nicking 3hp from your engine so why not make it work harder when you don’t need the power and lay off when you do.

The system fails when motorhome manufacturers add leisure batteries to a system that is not expecting them without providing a B2B. In my opinion the “not so smart” ones are the converters who haven’t bothered to understand what is needed. The B2B puts a load on the engine battery but the smart alternator copes with this in the same way as it copes with headlights and electrically heated windows by monitoring the engine battery voltage. If the battery voltage drops too far the alternator will cut in and work harder and ignore its energy saving until the battery voltage is back where it wants it.

Edit. The post at #48 I was replying to has disappeared from my screen so I guess I have gone on someone’s ignore list. I have an alert to tell me that my post here has now been quoted but I can’t see this either so I am not in a position to respond. Quoted and silenced, not sure I like that.
 
Last edited:
Pausim said:
No voltage = no power.
Click to expand...
Correct, but the alternator never has no voltage.

Pausim said:
If the battery voltage drops too far the alternator will cut in and work harder and ignore its energy saving until the battery voltage is back where it wants it.
Click to expand...
The alternator does not need to "cut in". It is working all the time - at the lower voltage needed to keep the starter battery at its required minimum level of charge.

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We were in Belgium a couple of years ago guy next door in a new pvc couldn’t start went to help he said battery reading fully charged so I took the readings yes was fully charge on battery terminals but when on wiring was 11.5 the positive connector was loose but was fully tightened had sone wire to put around post then tightened all good.said he was going straight to a main dealer.
 
Russell's Dad said:
UPDATE.
New starter motor fitted and no problems this trip!!! Happy days.
Click to expand...
That's interesting, since a year ago , mine has stated every time, then today ,went and got some fuel , came back and it failed to start for 20 minutes , then started no problems, been a whole year😪.
How much would the starter have been.??
My MH is now 3 years old and 7,000 miles.
 
NASHMAN600 said:
That's interesting, since a year ago , mine has stated every time, then today ,went and got some fuel , came back and it failed to start for 20 minutes , then started no problems, been a whole year😪.
How much would the starter have been.??
My MH is now 3 years old and 7,000 miles.
Click to expand...
I don't know the final costs as my warranty covered it. Sorry. Hope you get fixed.
For info. My problems were when the engine was hot ( long runs in hot weather). It appears that a faulty starter solenoid can stick in these conditions , but whether it was this or just a bad earth I'll never know.
 
A hot starter can indeed give problems; I had the same issue on a kit car running a 2.0l Zetec. A thick Ali plate bent and cut to shape acted as a rudimentary "heat shield". Seemed to do the trick as I member forgetting to put it back after a service and was stuck for 20min on a couple of occasions while it cooled down.

Could always tap it with the hammer...
 
Having had similar problems my money is on the battery terminals or the earth going from alternator to chassis.
9 times out of 10 that's the issues.

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Russell's Dad said:
That all makes perfect sense, although I thought the b2b and fridge power draw would cause the alternator to kick in to charge the starter battery, even when the engine is under load/cruising?? Is it not the case that the alternator should provide charge when required ( as opposed to all time as ordinary alternators do)?
Click to expand...
If the alternator is outputting a voltage of 12.2V, that is fine for powering the fridge and the B2B. The alternator can supply power at that voltage, which is OK for running all the vehicle loads like lights, fan wipers etc. It only increases the voltage, to 14.5V or so, when the vehicle management system decides the engine is in overrun or braking. That's the voltage required to charge a battery.
 

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