General 2919 Fiat 500 - How to operate automatic stop-start

[eponymous1212]

How long have you had the car?

I was just thinking if it is a 2019 car and bought new just before the pandemic, it may have spend most of its short life not going anywhere restricted by lock downs. So while the battery isn't that old it may not hold a charge well because of sitting around for years with very little use, or one trip a week to tesco 1 mile down the road for 6 months and little else.

Thanks, Andy. I think you've hit the nail on the head. I purchased the car when it was one year old to take advantage of depreciation. It had done relatively high mileage. Since having owned it, I have been doing approximately 1250 miles per year. I am purchasing a voltmeter that plugs into the cigarette lighter holder, so it will be interesting to see what that tells me.

 

[John202020]

Since having owned it, I have been doing approximately 1250 miles per year.

There's the answer why the ss doesn't work as expected, but if you intentionally stall it, it should re start

 

[eponymous1212]

There's the answer why the ss doesn't work as expected, but if you intentionally stall it, it should re start

Thanks, John. It seems like you only need to turn the engine off when actually stationary. So you do not necessarily need to do so when in a line of slow-moving traffic (can anyone confirm?). As such, I shall simply turn the ignition off, and on, when the car is stationary. Jus means extra wear and tear on the starter motor rather than the battery.

 

[The Panda Nut]

Thank you that's very helpful. Do you know if the stop-start is run off a separate battery? It's a relatively new (2019) and low-mileage car. As far as I know, the battery is healthy. In the old days cars used to have an ammeter. Do you know whether the Fiat 500 has any warning lights if the battery needs a charge, or are there any other ways of checking battery health? Many thanks, Denis

No you just have one battery. My car is also 2019 and to date the battery is still good though at four and a half years it could go anytine. Stop start batteries tend not to last as long as standard ones but I am hoping for better than 5 years. If you chagre the battery without disconnecting the negative terminal, which is quick release, it can get disorganised and then the computer deosnt know of the battery is fully charged or not. This could caus ethe s/s system to malfunction.

 

[The Panda Nut]

There's the answer why the ss doesn't work as expected, but if you intentionally stall it, it should re start

It does this is you uninterntionally stall. Its a bit slow to pick up the peices so makes stalling even more embarassing!

 

[eponymous1212]

No you just have one battery. My car is also 2019 and to date the battery is still good though at four and a half years it could go anytine. Stop start batteries tend not to last as long as standard ones but I am hoping for better than 5 years. If you chagre the battery without disconnecting the negative terminal, which is quick release, it can get disorganised and then the computer deosnt know of the battery is fully charged or not. This could caus ethe s/s system to malfunction.

Thanks, Panda. My cigarette lighter voltmeter should be arriving soon. Doing short local runs is definitely the problem. I was wondering, would running the engine when stationary at around 4,000 revs be a good way of charging the battery? (Obviously, I would do this somewhere where it doesn't cause a nuisance.)

 

[AndyRKett]

I am purchasing a voltmeter that plugs into the cigarette lighter holder, so it will be interesting to see what that tells me.

Nothing at all I suspect. Really there is very likely to be nothing “wrong” with the battery. Others mention stop start batteries not lasting long but the truth is, that on many other cars they cause very little problems compared to fiat.

Really the problem lies in the fiat stop start system which is very fickle. Imagine when a battery is new and it’s “100%” good

Everyone else’s cars are happy for the stop start to carry on working fine if the battery is old and operating at 75% of its original new capacity
fiat on the other hand requires the battery to be at 90% of the original capacity before stop start stops working, these are figures I plucked out of the air not actually based on any scientific numbers but the example is that fiat cars are more fussy about the condition of the battery than any other manufacture

As such, I shall simply turn the ignition off, and on, when the car is stationary. Jus means extra wear and tear on the starter motor rather than the battery.

don’t do this, modern cars are not designed for it, you can cause electrical faults as the computers are turned off and booted up repeatedly.
N years gone by a computer in a car was pretty simple chip with inputs and outputs and not a lot else but these days they’re are way more complex with technology compatible to top end computers from 15 - 20 years ago, they don’t like being turned on and off repeatedly, and quite often if you turn the ignition off then the cars lights might power off, you could be deactivating vital safety systems like airbags when the system is off which would otherwise protect you if someone crashed into you

 

[eponymous1212]

Nothing at all I suspect. Really there is very likely to be nothing “wrong” with the battery. Others mention stop start batteries not lasting long but the truth is, that on many other cars they cause very little problems compared to fiat.

Really the problem lies in the fiat stop start system which is very fickle. Imagine when a battery is new and it’s “100%” good

Everyone else’s cars are happy for the stop start to carry on working fine if the battery is old and operating at 75% of its original new capacity
fiat on the other hand requires the battery to be at 90% of the original capacity before stop start stops working, these are figures I plucked out of the air not actually based on any scientific numbers but the example is that fiat cars are more fussy about the condition of the battery than any other manufacture


don’t do this, modern cars are not designed for it, you can cause electrical faults as the computers are turned off and booted up repeatedly.
N years gone by a computer in a car was pretty simple chip with inputs and outputs and not a lot else but these days they’re are way more complex with technology compatible to top end computers from 15 - 20 years ago, they don’t like being turned on and off repeatedly, and quite often if you turn the ignition off then the cars lights might power off, you could be deactivating vital safety systems like airbags when the system is off which would otherwise protect you if someone crashed into you

Andy, thanks. That's extremely helpful. It transpires that the regulation has been around for years. It's probably difficult to enforce, and I don't know of anyone who has been fined.

 

[eponymous1212]

Nothing at all I suspect. Really there is very likely to be nothing “wrong” with the battery. Others mention stop start batteries not lasting long but the truth is, that on many other cars they cause very little problems compared to fiat.

Really the problem lies in the fiat stop start system which is very fickle. Imagine when a battery is new and it’s “100%” good

Everyone else’s cars are happy for the stop start to carry on working fine if the battery is old and operating at 75% of its original new capacity
fiat on the other hand requires the battery to be at 90% of the original capacity before stop start stops working, these are figures I plucked out of the air not actually based on any scientific numbers but the example is that fiat cars are more fussy about the condition of the battery than any other manufacture


don’t do this, modern cars are not designed for it, you can cause electrical faults as the computers are turned off and booted up repeatedly.
N years gone by a computer in a car was pretty simple chip with inputs and outputs and not a lot else but these days they’re are way more complex with technology compatible to top end computers from 15 - 20 years ago, they don’t like being turned on and off repeatedly, and quite often if you turn the ignition off then the cars lights might power off, you could be deactivating vital safety systems like airbags when the system is off which would otherwise protect you if someone crashed into you

Again, Andy, thanks. This is extremely helpful advice.

 

[Piccolo Nero e Bella]

If your battery has just 'lost its edge', causing S/S not to activate, the voltage monitor probably won't reveal much, as AndyRKett says. In my case the (then) new car's battery was still rated good enough for S/S to stop the engine, but the the voltage dropped rapidly; from an indicated 14.2V down to 11.6V in less than ten seconds, even without lights or AC on, at which point the S/S quickly stepped in and restarted it. In that case the monitor came into its own and showed the problem.

I'm not sure about later 500's but if I turn my engine off with the key both the headlights and brake lights also turn off, not desirable in traffic. It also means other systems have to reboot and reconnect, such as satnav, Bluetooth and dashcams, and if the stop is brief they can get confused if they haven't had time to shut down completely. In any case with FIAT's system you're still using the same starter motor and battery whether it's done by S/S or manually.

Is there a minimum time one can allow a car to idle under the legislation you mention?

My S/S EFB battery is now six years old and the S/S still works properly but conditions here are a bit kinder to batteries.

 

[eponymous1212]

If your battery has just 'lost its edge', causing S/S not to activate, the voltage monitor probably won't reveal much, as AndyRKett says. In my case the (then) new car's battery was still rated good enough for S/S to stop the engine, but the the voltage dropped rapidly; from an indicated 14.2V down to 11.6V in less than ten seconds, even without lights or AC on, at which point the S/S quickly stepped in and restarted it. In that case the monitor came into its own and showed the problem.

I'm not sure about later 500's but if I turn my engine off with the key both the headlights and brake lights also turn off, not desirable in traffic. It also means other systems have to reboot and reconnect, such as satnav, Bluetooth and dashcams, and if the stop is brief they can get confused if they haven't had time to shut down completely. In any case with FIAT's system you're still using the same starter motor and battery whether it's done by S/S or manually.

Is there a minimum time one can allow a car to idle under the legislation you mention?

My S/S EFB battery is now six years old and the S/S still works properly but conditions here are a bit kinder to batteries.

Piccolo, Thanks. You will see all your points, and more, are covered in this article: https://coxautoservice.net/car-main...dling is,your engine on when it is not needed.

I have tried, without success, to obtain information on the degree to which the regulation is enforced. What doesn't auger well is that it is the local authority that is responsible for enforcing the regulation. Where I live has recently been designated a Low Traffic Neighbourhood. The revenue generated by the traffic cameras for the council is phenomenally high.

 

[jrkitching]

Really there is very likely to be nothing “wrong” with the battery.

Everyone else’s cars are happy for the stop start to carry on working fine if the battery is old and operating at 75% of its original new capacity
fiat on the other hand requires the battery to be at 90% of the original capacity

Both statements are true.

The bottom line is that if you want stop start to work, you'll need to replace the battery. If you're happy with it not working, the battery will likely be fine for some while yet.

 

[gazz_bee]

Piccolo, Thanks. You will see all your points, and more, are covered in this article: https://coxautoservice.net/car-maintenance/engine/should-you-turn-off-engine-at-traffic-lights#:~:text=The short answer, is yes: engine idling is,your engine on when it is not needed.

I have tried, without success, to obtain information on the degree to which the regulation is enforced. What doesn't auger well is that it is the local authority that is responsible for enforcing the regulation. Where I live has recently been designated a Low Traffic Neighbourhood. The revenue generated by the traffic cameras for the council is phenomenally high.

Probably better referring to the Highway Code's Rule 123 as a layperson's version of the Construction and Use Regs (Clauses 98 and 107) rather than a random website. The legislation significantly predates the widespread implementation of start/stop and was intended to deal with nuisance behaviour rather than drivers genuinely waiting in a queue of traffic.

Rule 123​

The driver and the environment. You MUST NOT leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road. Generally, if the vehicle is stationary and is likely to remain so for more than a couple of minutes, you should apply the parking brake and switch off the engine to reduce emissions and noise pollution. However it is permissible to leave the engine running if the vehicle is stationary in traffic or for diagnosing faults.

 

[eponymous1212]

Probably better referring to the Highway Code's Rule 123 as a layperson's version of the Construction and Use Regs (Clauses 98 and 107) rather than a random website. The legislation significantly predates the widespread implementation of start/stop and was intended to deal with nuisance behaviour rather than drivers genuinely waiting in a queue of traffic.

Rule 123​

The driver and the environment. You MUST NOT leave a parked vehicle unattended with the engine running or leave a vehicle engine running unnecessarily while that vehicle is stationary on a public road. Generally, if the vehicle is stationary and is likely to remain so for more than a couple of minutes, you should apply the parking brake and switch off the engine to reduce emissions and noise pollution. However it is permissible to leave the engine running if the vehicle is stationary in traffic or for diagnosing faults.

Thank you, Gazz-bee. That's extremely helpful.

 

[Piccolo Nero e Bella]

Piccolo, Thanks. You will see all your points, and more, are covered in this article: https://coxautoservice.net/car-maintenance/engine/should-you-turn-off-engine-at-traffic-lights#:~:text=The short answer, is yes: engine idling is,your engine on when it is not needed.

I have tried, without success, to obtain information on the degree to which the regulation is enforced. What doesn't auger well is that it is the local authority that is responsible for enforcing the regulation. Where I live has recently been designated a Low Traffic Neighbourhood. The revenue generated by the traffic cameras for the council is phenomenally high.

To be honest I didn't find that article particularly enlightening but I did do a general search on UK regulations pertaining to idling engines and it seems to me the various legislation is aimed at people who leave their engines idling while parked, particularly outside schools and such. It doesn't appear that you'll be fined if you fluff a gear change on the High Street.

 

[eponymous1212]

To be honest I didn't find that article particularly enlightening but I did do a general search on UK regulations pertaining to idling engines and it seems to me the various legislation is aimed at people who leave their engines idling while parked, particularly outside schools and such. It doesn't appear that you'll be fined if you fluff a gear change on the High Street.

Thank you for all your excellent help and advice Piccolo.