Fiat Smart Alternator problems

[barge1914]

Anyone had problems with smart alternator as fitted on recent (3 year old) Euro 6 motorhomes. My engine battery charge voltage fluctuates randomly between 12.4 and 14.2V, it has always seemed somewhat erratic but now much more so? It wouldn’t start for 10 minutes or so after a break this morning, even though when it did it was immediate with no sign of weakness from the battery in cranking.

Presently at a garage in Ayr where AA took me. They’ve measured voltage at the alternator terminals and their readings agree with mine, but they are somewhat flummoxed. Despite the low readings it usually rises back to 12.6V after a rest.

I can’t get a Fiat place to even look at it for over a week and we are due on the ferry to Ireland on Wednesday. Reluctant to just order a new alternator owing to high cost, and uncertainty that the problem may actually lie with other elements of the smart alternator control electrics. Looking online there seem to have been lots of problems with these, but no clear answers.

Just wondered if others on the forum had had the issue.

 

[trevskoda]

I have been told its the electrics and not the alt itself, but if the battery is up it will drop the voltage.

 

[Chrisinchip]

I second Trevskoda’s comment and add that different manufacturers will have different algorithms; it is all about reducing fuel consumption and not maintaining a fully charged battery. (Hence the need for a DC-DC charger to ensure maximum charging of a leisure battery from a smart alternator).

But your comment “it usually rises back to 12.6V after a rest.” is interesting. I wonder if there is a load on the battery pulling the voltage down and when the load switches off, the battery voltage gradually recovers. If this scenario is correct then it’s a matter of determining what that load may be.

Firstly I’d make sure that it isn’t anything to do with the conversion (i.e. clarify that it’s a Fiat problem) so isolate habitation electrics from the vehicle battery by removing the fuse(s) from the leisure connection(s) at/near the vehicle battery. There may be more than one fused connection. N.B. If you disconnect any wires, assume they can still be or become live and insulate them before any testing. (Leisure electrics may “feed” a vehicle battery from solar, 240v, etc.) The sort of issue I’m trying to eliminate here is a DC-DC charger that’s slow in switching off or perhaps a dodgy fridge relay. This is so dependent on conversion specifics.
Determining whether it is a Fiat or conversion load dragging the voltage down will inform the next step.

[edit] ---
Afterthought in the shower : There may also be a Service Supply (I don't know what its proper name is!) providing vehicle battery power through fused outlets which could also be utilised by the converter. Ford provide such a block down by the driver's seat on the Transit, possibly because it is near the battery.

And linking terminology in Okta's post that follows: We are referring to the same thing when talking about a DC-DC charger and B2B/Battery booster.
---

Hope that helps and isn’t a massive red herring.

 

[Okta]

The voltage fluctuations are what smart alternators do but changing the alternator will not make a difference because it is really the ECU controlling the alternator. Not starting sounds like a separate problem.

If your motorhome only has a split charge relay for charging the leisure battery this needs changing. Linking the engine battery and leisure battery with a simple relay causes problems for charging both batteries. With a smart alternator you need a B2B/battery booster, this has been a well known for several years, I first learned about it in 2015.

 

[Chrisinchip]

If your motorhome only has a split charge relay for charging the leisure battery this needs changing. Linking the engine battery and leisure battery with a simple relay causes problems for charging both batteries. With a smart alternator you need a B2B/battery booster, this has been a well known for several years, I first learned about it in 2015.

... and sadly the leisure industry has been slow to catch up. Mine was registered in 2020 and relied on a split charge relay until 8 weeks ago!

 

[Okta]

Some manufacturers were onto it by 2020 but sadly others are very slow learners. Possibly the ones who blindly follow NCC standards for caravans.

 

[barge1914]

I’ve decided to leave it for now. Arrived at Ballantrae this morning, it’s reading 12.7V and the hab battery is also well charged. I agree it’s neither a battery or alternator problem. Possibly ECU controlling the alternator, but so long as it keeps starting and the battery has a charge I’ll ignore it and get on the ferry to Belfast. I suspect it’s always been the same from new as the subject came up previously in early days and I’m not convinced it was resolved then. It may just be a case of ‘that’s how it works’.

I wouldn’t be surprised if I’d inadvertently put foot on brake and accelerator at the same time, it wouldn’t be the first time after driving a manual for a month or two I do I bit of foot fumbling! That could explain non starting episode.

Fiat want £340 just to investigate and can’t book me in until 7th August. I’ll see how it goes.

 

[merl]

I’ve decided to leave it for now. Arrived at Ballantrae this morning, it’s reading 12.7V and the hab battery is also well charged. I agree it’s neither a battery or alternator problem. Possibly ECU controlling the alternator, but so long as it keeps starting and the battery has a charge I’ll ignore it and get on the ferry to Belfast. I suspect it’s always been the same from new as the subject came up previously in early days and I’m not convinced it was resolved then. It may just be a case of ‘that’s how it works’.

I wouldn’t be surprised if I’d inadvertently put foot on brake and accelerator at the same time, it wouldn’t be the first time after driving a manual for a month or two I do I bit of foot fumbling! That could explain non starting episode.

Fiat want £340 just to investigate and can’t book me in until 7th August. I’ll see how it goes.

I think I'd do the same, I wouldn't fancy a £340 bill to tell me they cant find a fault, lets face it that's almost certainly what'll happen eh?
If it's cranking but not starting then that's NOT a battery issue and something different like a immobiliser issue perhaps?
I plugged my ciggy voltage plug into my car cos it said there was a charge issue on the dash, It has a smart alt and the voltage fluctuates way more than the van which I'm used to which isn't a smart alt.
As has already been said, smart alt programming seems to vary between makers etc but if the battery is getting charged and holding then I cant see an issue however you dont want the battery voltage going above 15V on a regular basis and for a sustained period, that kind of voltage would make me question what's going on.
Good luck

 

[wildebus]

Anyone had problems with smart alternator as fitted on recent (3 year old) Euro 6 motorhomes. My engine battery charge voltage fluctuates randomly between 12.4 and 14.2V, it has always seemed somewhat erratic but now much more so? It wouldn’t start for 10 minutes or so after a break this morning, even though when it did it was immediate with no sign of weakness from the battery in cranking.

Presently at a garage in Ayr where AA took me. They’ve measured voltage at the alternator terminals and their readings agree with mine, but they are somewhat flummoxed. Despite the low readings it usually rises back to 12.6V after a rest.

I can’t get a Fiat place to even look at it for over a week and we are due on the ferry to Ireland on Wednesday. Reluctant to just order a new alternator owing to high cost, and uncertainty that the problem may actually lie with other elements of the smart alternator control electrics. Looking online there seem to have been lots of problems with these, but no clear answers.

Just wondered if others on the forum had had the issue.

Try a little experiment ....
When you see the battery voltage fluctating when driving (out of interest, how are you reading this voltage when driving? voltmeter on the dash?), turn the headlights on and see if the voltage settles down to a less erratic pattern.
Generally on vehicles with smart alternators, you can kind of 'dumb them down' by having a higher constant electrical load on the start battery - such as headlights (which will be around 8A or so).

Often with smart alternators, a "full" starter battery is not regarded as being around the 12.7V mark, but at the 12.4V reading (it is not really full, but leaves space for regenerative braking and charge 'dumps').

Don't know about your starting issues and if it is related, but it might be worth considering a purchase of a Lithium jump-start booster pack as a bit of reassurance on your travels if you think the Vehicle battery is a bit suspect. Get one from Amazon or if time is too critical to wait for delivery, maybe halfords or similar?

 

[GWAYGWAY]

Make sure your brake light switch is OK as that affects the ‘smart bit’ of the output also tighten all of the earth connections.

 

[barge1914]

Try a little experiment ....
When you see the battery voltage fluctating when driving (out of interest, how are you reading this voltage when driving? voltmeter on the dash?), turn the headlights on and see if the voltage settles down to a less erratic pattern.
Generally on vehicles with smart alternators, you can kind of 'dumb them down' by having a higher constant electrical load on the start battery - such as headlights (which will be around 8A or so).

Often with smart alternators, a "full" starter battery is not regarded as being around the 12.7V mark, but at the 12.4V reading (it is not really full, but leaves space for regenerative braking and charge 'dumps').

Don't know about your starting issues and if it is related, but it might be worth considering a purchase of a Lithium jump-start booster pack as a bit of reassurance on your travels if you think the Vehicle battery is a bit suspect. Get one from Amazon or if time is too critical to wait for delivery, maybe halfords or similar?

Thanks. I had just about come to that conclusion about not being regulated for full charge after travelling today. I’m monitoring it on the voltmeter readout and graph on the Phantom alarm and tracker app. Probably not totally accurate but when I’ve compared it with control panel readout the discrepancy is usually only around 1V, with a multimeter somewhere in between. It seems a happy 12.7V now after settling down for a few hours.

Looking back at the charge graph over the last 30 days it was performing in the same way both on my return from Spain, and a trip up to Edinburgh last weekend. I had no battery or starting problems then, so I am more inclined to think non starting was foot-fumbling with brake and accelerator after driving a manual vehicle.

 

[wildebus]

Thanks. I had just about come to that conclusion about not being regulated for full charge after travelling today. I’m monitoring it on the voltmeter readout and graph on the Phantom alarm and tracker app. Probably not totally accurate but when I’ve compared it with control panel readout the discrepancy is usually only around 1V, with a multimeter somewhere in between. It seems a happy 12.7V now after settling down for a few hours.

Looking back at the charge graph over the last 30 days it was performing in the same way both on my return from Spain, and a trip up to Edinburgh last weekend. I had no battery or starting problems then, so I am more inclined to think non starting was foot-fumbling with brake and accelerator after driving a manual vehicle.

Does your van need any pedals pressed to be able to start, or gearstick in Neutral (if Auto?).
Mine doesn't, but my car will not start if I don't have the clutch pedal depressed and I have a couple of times wondered why the car won't start until I remembered (By habit, I have always tended to push the clutch in anyway so not something that I have thought about so the car hasn't changed my procedures and ingrained a specific process in the brain )

 

[barge1914]

Starts normally with gearstick in park. But I am used to pushing clutch in starting manual car. I could have gone into autopilot and pressed brake with left (clutch) and used right on accelerator. Memory blank on that…age thing!

 

[marchie]

Does your van need any pedals pressed to be able to start, or gearstick in Neutral (if Auto?).
Mine doesn't, but my car will not start if I don't have the clutch pedal depressed and I have a couple of times wondered why the car won't start until I remembered (By habit, I have always tended to push the clutch in anyway so not something that I have thought about so the car hasn't changed my procedures and ingrained a specific process in the brain )

Our Tiguan has push button stop/start system and will not start unless the clutch is depressed [sensors everywhere]. If you depress the clutch when starting, it reduces the strain from the transmission and makes starting easier, a useful aid if/when the battery is beginning to show its age!

Steve

 

[trevskoda]

Our Tiguan has push button stop/start system and will not start unless the clutch is depressed [sensors everywhere]. If you depress the clutch when starting, it reduces the strain from the transmission and makes starting easier, a useful aid if/when the battery is beginning to show its age!

Steve

Pushing a clutch in causes drag and over time wear on the diaphram and release bearing.
In the old days with hand cranking how would that work unless you have very long legs LOL.

 

[Mikebike]

Some manufacturers were onto it by 2020 but sadly others are very slow learners. Possibly the ones who blindly follow NCC standards for caravans.

I agree I had a T6 converted in 2016 and the small converter knew all about it and had fitted a b2b charger. Swapped it for an Autotrail pvc in 2021 to find that split charge had been fitted so problems with leisure charging and Autotrail didn't seem to know what to do. I had b2b fitted and all is well.

 

[Okta]

I agree I had a T6 converted in 2016 and the small converter knew all about it and had fitted a b2b charger. Swapped it for an Autotrail pvc in 2021 to find that split charge had been fitted so problems with leisure charging and Autotrail didn't seem to know what to do. I had b2b fitted and all is well.

UK constructors seem to have been particularly slow catching up with this technology, what they have in common is following NCC rules. I have done a few searches trying to find out whether the NCC rules have at last changed to take smart alternators into account. As far as I can make out the NCC construction rules are hidden away from the public so it is difficult to say who is responsible for this ridiculous situation. Obviously the constructors should have known about these well known issues but it probably doesn’t help having a trade body that may or may not have noticed that technology has moved on.

I think smart alternators are a great idea. They make sure that a few more BHP are available when needed for going up hills and then increase engine braking when slowing down to charge the battery.

 

[Chrisinchip]

Pushing a clutch in causes drag and over time wear on the diaphram and release bearing.
In the old days with hand cranking how would that work unless you have very long legs LOL.

apologies for going a little off-piste. Declutching removes the drag of turning a gearbox which is most significant when its oil is cold and thick. On balance, for a cold start, I suspect this saved more drag than the pressure on the thrust release bearing created. That said, as engine compression ratios increased the gearbox would have contributed a smaller proportion of the overall cold cranking effort required. Nevertheless any little bit can help a battery on its last legs.

 

[trevskoda]

apologies for going a little off-piste. Declutching removes the drag of turning a gearbox which is most significant when its oil is cold and thick. On balance, for a cold start, I suspect this saved more drag than the pressure on the thrust release bearing created. That said, as engine compression ratios increased the gearbox would have contributed a smaller proportion of the overall cold cranking effort required. Nevertheless any little bit can help a battery on its last legs.

The oil will be thin when cold, hence the 75/90, so very little drag, the more you use the clutch the faster it wears out, many of my toys have went round the clock 2/3 times without having to replace a clutch, mind you I made lots of money from folk wrecking cars over the years, esp the ones who sit at lights with the foot on clutch and brake, not forgetting the ones who drive with the foot resting on the pedal.

 

[molly 2]

I read on tinterweb that the charging parameters of a smart alternator can be changed by a computer re map .
My last motorhome had a smart alternator voltage could drop down to 12 v cruising on motorway then rise when going down hill , that is what smart alternators do , I would like to know if motor home manufacturers re program management systems to accommodate leasure batterys and motor home use