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Discussion Starter · #1 · (Edited)
Just wondering what people think about the S/S system?

Check out the below article:
http://autoexpert.com.au/buying-a-car/the-truth-about-automatic-engine-stop-start-systems

Does the Giulia use a capacitor for the restart rather than battery? Also, does it smartly shut down at an optimised crank rotation position for restarting?

I understand disabling S/S when the engine is cold is best to prevent unnecessary additional engine wear. That was seems straight forward to make sense of.

When in the city and the engine/oil is at full temp, I don't mind the S/S. That said, I like my music playing, Sat Nav active and AC running, and would prefer that power to come from the alternator rather than the battery. How long could the battery run these systems for (headlights are on too)?

If the engine was off too long due to S/S and the battery was drained too much, would the Giulia know to fire the engine back up to get the alternator running again?

If any experts can help out with these questions it would be appreciated.

Cheers
 

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The system is very smart and considers most of the items you listed before engaging, but it's is not a subtle thing by any means, if you take your foot off the brake too fast it will lurch hard forward, it also is very rough while starting, but the worst thing is that A/C turns off too. Porsche has electric A/C compressor so at least it's still cool in the car when the engine is off.
 

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2018 Q4 with Fiamenghi Ti exhaust, Race Mod, and Tecnico wheels.
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An online search for the battery that Giulia uses and for start-stop technology in general turns up some disturbing news.

First off the battery has electronics built into it. If you want your car to work right you will most likely be stuck buying only a MOPAR battery. Once there are electronics in the battery it seems likely that those electronics will be used for other purposes such as charge control. It sounds like 10-20 years from now your Giulia will be impossible to maintain. There is a finite chance that this sensor can be disconnected or altered to disable the start-stop feature, but without knowing the interaction with other parts of the cars controls I cannot recommend this approach. Hopefully this sensor is reliable, unlike the built-in charge controllers found in Lion batteries. My experience is that the most common cause of Lion battery failure is the charge controller has failed rather than that the chemical battery has developed a fault. Maybe MacGeek knows more about this MOPAR battery?

Secondly, cars with the start-stop feature that are driven in stop and go traffic have substantially reduced battery life. Estimates of 4-12 weeks of battery life if an "ordinary" lead acid battery is used. I could not find an estimated life span for a specialty start-stop battery.

Lastly, it looks like the MOPAR battery is flooded cell. That means you need to periodically check the acid level and top it up with distilled water from time to time. In addition, it means that lead contaminated sulphuric acid is going to coat the battery box inside your trunk. The more start-stop is used, the more this will be an issue.

Back to your question: the battery is rated 50AH at the 20 hour rate when fully charged. That means that you could reasonably draw 12.5AH or 750Amp-Minutes from the battery over a "short" period of time and expect to have enough reserve for the engine to start. Headlights on can be expected to draw 3-4Amps, depending on what headlights you have and assuming 10 watts for the taillight and trim lights. Your A/C is not running when the engine stops, instead only the fan is running. You can expect that 1 fan on high draws about 10Amps (2.5 Amps on low). The power consumption of the stereo is harder to estimate and I expect it is much higher if you have the 400Watt Harman Kardon option. I expect the value is between 5Amps and 40Amps, depending on what you are listening to and how loud. Thus we get a guesstimate of

750/(3+2.5+5) = 71 minutes MAX
750/(4+10+40) = 13.8 minutes MIN

Hopefully you aren't getting stuck stopped in traffic for more than a few minutes.

I think the bigger problem can happen if you are spending more time stopped than started over a long drive or over many days of driving. The car is supposed to manage this and not stop if the battery is getting too discharged.

On my pickup truck the battery charging system only uses voltage and battery temperature to control the charge rate. The battery box has a temperature sensor built into the bottom, allowing a choice of any battery that will fit and provide sufficient performance.
 

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Discussion Starter · #4 ·
Interesting and informative Lockem, thanks for sharing.

Some of your information on the battery seems to contradict the Giulia manual however? See page 224:

"The battery does not require the
electrolyte to be topped up with distilled
water. A periodic check carried out at an
Alfa Romeo Dealership is, however,
necessary to check efficiency."
 

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Interesting and informative Lockem, thanks for sharing.

Some of your information on the battery seems to contradict the Giulia manual however? See page 224:

"The battery does not require the
electrolyte to be topped up with distilled
water. A periodic check carried out at an
Alfa Romeo Dealership is, however,
necessary to check efficiency."
AlfaMale,

All flooded cell lead-acid batteries need periodic "water" checks. Sealed lead acid and AGM batteries generally do not, but also generally do not have removable caps on top that I see in the pictures of the battery on the Mopar EU site.

Some stationary batteries can be equipped with caps that contain a catalyst that will recombine hydrogen and oxygen to reduce water loss. This is usually found in off-grid solar system battery packs. I have no idea if the MOPAR battery has such a feature.
 

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The battery has no electronics in it. So, no need for a Mopar battery. The Intelligent Battery Sensor merely sits on the negative pole, and the battery ground wire then clips onto the IBS. It is not part of the battery, it doesn't need to be replaced with the battery. It stays with the car.

The sensor monitors voltage, current and temperature, and calculates 3 main metrics: State Of Charge (SOC), State Of Health (SOH), and State Of Function (SOF).

SOC, as the name suggests, represents the percentage of battery charge.
SOH is an index of battery aging, calculating the capacity degradation the battery has suffered with time.
SOF is the minimum voltage reached during cranking, so it relates to the cranking amperage the battery is capable of withstanding.

The 3 values combined give a picture of the ability of the battery to start the vehicle. With insufficient SOC or SOH, you may not be able to restart the car, and with insufficient SOF the voltage drop during cranking may be excessive for vehicle electronics.

The system automatically calibrates after any battery disconnection. Calibration can be completed once the car has been started at least twice, and it's been left parked for at least 4 hours with no power draw other than the vehicle systems.

The battery is not 50Ah, it's 80Ah or 95Ah depending on the market. US-market vehicles, iirc, have the 95Ah battery as standard. It's supplied by Varta (Johnson Controls), and it's what JC calls an Enhanced Flooded Battery. It does not need periodic top ups.
 

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Could MacGeek = Marchionne ?
 

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One thing I noticed today.... when the HVAC system is on manual and the Auto Stop/Start feature turns off the engine at a stop, the air blowing through the vents remains at a constant speed... no change.

However, if you leave the HVAC system on Auto and the Auto Stop/Start feature turns off the engine at a stop, the air blowing through the vents decreases dramatically which is very annoying.

Having the air remain at a constant speed is nice. I may have to leave this thing on manual for the time being unless there is an update to the HVAC system.
 

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MacGeek says he doesn't work for them but is friendly with the group. So a recently departed insider of some sort maybe, but one that left on good terms...or with his old passwords anyway.
 

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The start-Stop system is what it is. Obviously used by a variety of manufacturers to help increase their EPA mileage numbers. Hopefully Alfa does change it to be constantly off but I wouldn't count on it.
As suggested previously, just remember to disable it every time you start the car. Very easy to do, took me a few drives to get the hang of disabling it but its part of my starting procedure now.
 

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The start-Stop system is what it is. Obviously used by a variety of manufacturers to help increase their EPA mileage numbers. Hopefully Alfa does change it to be constantly off but I wouldn't count on it.
As suggested previously, just remember to disable it every time you start the car. Very easy to do, took me a few drives to get the hang of disabling it but its part of my starting procedure now.
No harder than pushing the button to close the garage.
 
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The start-Stop system is what it is. Obviously used by a variety of manufacturers to help increase their EPA mileage numbers. Hopefully Alfa does change it to be constantly off but I wouldn't count on it.
As suggested previously, just remember to disable it every time you start the car. Very easy to do, took me a few drives to get the hang of disabling it but its part of my starting procedure now.
Agreed! At least is a separate stand-alone button for a quick shut off of the system. When I drove the Masarati Ghibli, the only way to turn off the Auto Stop/Start feature is through the steering wheel menu - several button presses! Its horrible! And it comes back on when you re-start the car as the Giulia.

In the Ghibli, the only way to have a quick 1 button shut off is to engage the "Sport Mode" setting which automatically disables the Auto/Start feature but enables the loud exhaust note.
 

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Just to clarify, I am not, nor have I ever been, a FCA insider. While well informed and with good connections and sources, I am just a customer. You can always petition AR to hire me if you want to change that. :D
I personally don't care what your affiliation is with FCA, just so long as you keep providing much needed accurate information. I certainly appreciate all the info, schematics and insight you provide on this Forum. THANK YOU.
 
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