Three Months In An S5

[Joningy]

Couldn’t agree more. However the insistent message of ‘please focus on driving’ which ironically distracts me from driving!! Additionally the speed sign recognition that then picks up speed signs on side streets and hence informs me I am speeding!!!! The only bright side of this is it’s just a boing as bitching Betty appears to have disappeared! I test drove a BYD Seal hybrid which had much better’all round’ improvements; the voice control actually does something and you can answer and hang up the phone! Whilst I think the S5 is a reasonable car I feel let down by the avionics- totally let down. I am on the cusp of trading it in for a BYD especially now the road tax makes it an expensive car……

I now get a very peaceful drive in my S5, I've turned off all the annoying bings and bongs, but you'll need to turn down the volume in one of the menu's to totally stop the most annoying ones, I cant remember exactly how I turned down the sound, but it's all quite normal to drive now, so long as I remember to disable the custom pilot before I set off, I get a reminder if I do forget, we are deep in the countryside in a 30MPH zone, it bongs 3 times if I forget to disable the crud.

 

[emmrecs]

so long as I remember to disable the custom pilot before I set off

Did you actually mean enable the custom pilot?

 

[TimothyN]

That's an interesting bit of semantics. I would say that you are using the settings exclusively to disable things, no? Where's Bertrand Russell when you need him?

 

[emmrecs]

I think the point is that you have to enable the Custom Pilot button (each time you drive the car) if you have chosen settings which are NOT the car's defaults and have saved them to that button. By definition "custom" surely means "non-default" so, essentially, personalised and "my choice" of settings.

 

[Joningy]

Did you actually mean enable the custom pilot?I

Yes that's what I was trying to say, thanks for pointing it out @emmrecs. BUT it may have been a typo or it may have been predictive TEXT, could have been an age related furk up cheers!

 

[Joningy]

I think the point is that you have to enable the Custom Pilot button (each time you drive the car) if you have chosen settings which are NOT the car's defaults and have saved them to that button. By definition "custom" surely means "non-default" so, essentially, personalised and "my choice" of settings.

Exactly @emmrecs.

I've noticed my S5 Custom Pilot wont save driving in Eco mode, not sure if it's standard or another anomaly, but it's not something I use regularly.

Another thing, I regularly get a flash message telling me the 12V battery is low, but it's far from low, measured today @13.9V (all electrics off car unlocked) on the settings readout, corroborated with a separate meter reading, seems to be a bit odd, no idea why!

I bought a Bluetooth battery monitor due to regular (incorrect) messages, but as previously mentioned here, why has the 12V battery SOC not included on the MG iSmart app as it was on my MG4?

 

[dx4100]

Exactly @emmrecs.

I've noticed my S5 Custom Pilot wont save driving in Eco mode, not sure if it's standard or another anomaly, but it's not something I use regularly.

Another thing, I regularly get a flash message telling me the 12v battery is low, but it's far from low, measured today @13.9v, (all electrics off car unlocked) on the settings readout, corroborated with a separate meter reading, seems to be a bit odd, no idea why!

I bought a Bluetooth battery monitor due to regular (incorrect) messages, but as previously mentioned here, why has the 12v battery SOC not included on the MG iSmart app as it was on my MG4?

Your car needs to be in READY mode to be looking after the 12V battery the same way an ICE car would if the engine was turned on. If you put your foot on the brake pedal and release that is enough.

I managed to flatten mine when I was installing a screen protector in the car by not doing this.

 

[Joningy]

Your car needs to be in READY mode to be looking after the 12V battery the same way an ICE car would if the engine was turned on. If you put your foot on the brake pedal and release that is enough.

I managed to flatten mine when I was installing a screen protector in the car by not doing this.

I only get the message of low 12V battery when the car is in "ready mode" of course, but what I don't understand is with all electrics turned off, my 12V battery is reading 13.9V.
I purposely left the car unlocked overnight, by switching off at the infotainment screen, I opened the drivers door this morning and released the bonnet catch to check the battery voltage without entering the car, I didn't get into the car, so it was virtually dead, with nothing running, but still the battery read 13.9V, I then booted the car up to check the battery reading within the settings of the infotainment screen, it was reading an identical 13.9 volts to what I'd measured previously with the the car switched off.
So why am I getting a false message alert saying low 12V battery?
I'm now happy there's nothing untoward wrong with the 12V battery, the fault is clearly another software glitch!

 

[Coulomb]

I purposely left the car unlocked overnight, by switching off at the infotainment screen, I opened the drivers door this morning and released the bonnet catch to check the battery voltage without entering the car, I didn't get into the car, so it was virtually dead, with nothing running, but still the battery read 13.9V, I

I didn't think that a lead acid battery would retain 13.9V overnight.

If you leave the bonnet unlocked and watch the auxiliary battery voltage, what happens to the voltage when you lock the car (it will probably beep the horn briefly)? In my experience, it should slowly (over half an hour or so) drift down to about 12.8V, or at most 13.2V. Though maybe with much colder ambient temperatures than I ever experience, things are different.

I'm wondering if your "driver weight detected" switch is always on. So the 13.9V is actually from the DC-DC.

 

[Joningy]

I didn't think that a lead acid battery would retain 13.9V overnight.

If you leave the bonnet unlocked and watch the auxiliary battery voltage, what happens to the voltage when you lock the car (it will probably beep the horn briefly)? In my experience, it should slowly (over half an hour or so) drift down to about 12.8V, or at most 13.2V. Though maybe with much colder ambient temperatures than I ever experience, things are different.

I'm wondering if your "driver weight detected" switch is always on. So the 13.9V is actually from the DC-DC.

It's a mystery @Coulomb, you are absolutely correct, the normal resting voltage of a 12v lead acid battery is in the region of 12.6 volts.
I wonder if anyone else has measured their 12v battery without entering the car to activate the startup procedure?
In my mind it's somehow, rightly or wrongly connected to the high voltage battery, thus maintaining the high level SOC.
Any ideas folks, before I hassle the main dealer again, probably a waste of time trying to contact MG direct from my recent experiences, I'm concerned it's not correct!

 

[emmrecs]

I wonder if anyone else has measured their 12v battery without entering the car to activate the startup procedure?

Yes, I have!

Very long story, short: I have now experienced four times the failure of the 12v on my car, leading to requirement for use of the Mechanical Key and my Battery Booster. (Local dealer has had the car in for diagnostic investigation - 2 days - and could find no problem but have needed the booster (and key) again since, so it's going back for further investigation in the New Year.)

With regard to the question raised: because I'm now hyper-aware of the problem I yesterday put the 12v on a battery charger. By 5pm it was reported as "Full" and the voltage (as recorded on the charger's meter) showed 12.8. This morning I went to check it again (without starting the car, so no sitting on the driver's seat or pressing the brake pedal) and using that same meter it was 12.5. (I'm meticulously logging all this so I can show the dealer exactly what is happening, or not happening!)

I have no idea whether an overnight drop of 0.3v is or is not significant?

 

[dx4100]

12.6–12.8 V → Fully charged
12.4 V → ~75% charged
12.2 V → ~50% charged
12.0 V → ~25% charged
Below 11.8 V → Very low / likely discharged

In a normal ICE car anything below 12.4v might see the car struggle to start. Should be fine in an EV until you get below 12v.

The battery should always be around or above 12.4 when resting is my understanding. The car should be maintaing it at various points.

Currently that looks fine to me.

 

[stevedee]

If you leave the car for a few hours (e.g. overnight) & then measure:-
~12.6 - 12.8V > Healthy
~12.2 - 12.4V > weak

When "on" >= 13.8V is normal due to active DC/DC converter.

Also bear in mind that low cost multimeter's have a +/- 1 count tolerance in addition to a +/-% figure.
i.e. if your display reads (say) 12.5 the true value could be 12.4 to 12.6 or worse.

Note: this is just a guide, but if losing 0.3V it may be significant.
I'd suggest leaving it for (say) 2 hrs after charging, then measure again in the morning (after a longer break) and compare those 2 figures.

 

[Joningy]

My S5 conundrum kinda semi solved
According to a notice on the driver’s screen when turning off the power, “12v battery level is critical” as photo.

To check 12v battery state of charge (SOC) in the car, touch car icon bottom on the infotainment screen and then touch STATUS, 12V BATTERY still reading 13.9v despite the battery reading near 15 volts with my separate digital meter.

With bonnet up and car locked, after a few minutes a fairly audible clunk was heard, obviously a relay and the voltage dropped off to the expected 12.7, within a few seconds of unlocking the car, but not opening the door, the voltage returned to high 14’s volts, however, left unlocked for a few minutes, but not entering the car it reverted to 12.7v, then after a few more minutes, strangely, the solenoid cut in and out a couple of times, but eventually settled and remained at the expected 12.7 resting voltage.

Conclusion.
Initial power up starts on car unlocking (probably as expected)

The car goes through several closing down phases and solenoid clunks can be heard.

The 12v battery settles to the expected 12.7 “ish” volts, which is correct and more importantly stays there overnight, thus showing the battery is in good nick. PERFIK.

But the reason I’m commenting on this issue in the first place, why the furk am I getting a warning telling me the battery is low, its another stupid software glitch which others less able to check out will be concerned about.

C’MON MG get these little issues sorted!

However, I’m feeling better about it now and if others are experiencing similar, it’s probably the same as mine, not much need for concern, except poor ole @emmrecs , whose problem is possibly related to mine, but much worse, good luck @emmrecs .

Merry Christmas All.

 

[Joningy]

If you leave the car for a few hours (e.g. overnight) & then measure:-
~12.6 - 12.8V > Healthy
~12.2 - 12.4V > weak

When "on" >= 13.8V is normal due to active DC/DC converter.

Also bear in mind that low cost multimeter's have a +/- 1 count tolerance in addition to a +/-% figure.
i.e. if your display reads (say) 12.5 the true value could be 12.4 to 12.6 or worse.

Note: this is just a guide, but if losing 0.3V it may be significant.
I'd suggest leaving it for (say) 2 hrs after charging, then measure again in the morning (after a longer break) and compare those 2 figures.

My multi-meter is a low cost version @stevedee, but tested against my neighbours (electronics engineer's) it's pretty much spot on, at least as you infer, within the bounds of acceptability in this instance and probably + or - 0.1 volts is close when considering a couple of volts differential. see my latest conclusion probably below, but who knows.

 

[dx4100]

My S5 conundrum kinda semi solved
According to a notice on the driver’s screen when turning off the power, “12v battery level is critical” as photo.
View attachment 42096

To check 12v battery state of charge (SOC) in the car, touch car icon bottom on the infotainment screen and then touch STATUS, 12V BATTERY still reading 13.9v despite the battery reading near 15 volts with my separate digital meter.
View attachment 42097

With bonnet up and car locked, after a few minutes a fairly audible clunk was heard, obviously a relay and the voltage dropped off to the expected 12.7, within a few seconds of unlocking the car, but not opening the door, the voltage returned to high 14’s volts, however, left unlocked for a few minutes, but not entering the car it reverted to 12.7v, then after a few more minutes, strangely, the solenoid cut in and out a couple of times, but eventually settled and remained at the expected 12.7 resting voltage.

Conclusion.
Initial power up starts on car unlocking (probably as expected)

The car goes through several closing down phases and solenoid clunks can be heard.

The 12v battery settles to the expected 12.7 “ish” volts, which is correct and more importantly stays there overnight, thus showing the battery is in good nick. PERFIK.
View attachment 42098

But the reason I’m commenting on this issue in the first place, why the furk am I getting a warning telling me the battery is low, its another stupid software glitch which others less able to check out will be concerned about.

C’MON MG get these little issues sorted!

However, I’m feeling better about it now and if others are experiencing similar, it’s probably the same as mine, not much need for concern, except poor ole @emmrecs , whose problem is possibly related to mine, but much worse, good luck @emmrecs .

Merry Christmas All.

State of charge is a percentage. Its the percentage of how much of your battery is being used. While related to the voltage its not exactly the same thing and they can diverge. Something for you to keep in mind.

The three main readings from a bettery will be...

SOC % - how much capacity is being used
SOH % - how healthy your battery is
Volts - current volts

You are currently measuring volts. Get yourself a decent battery tester and it will tell you all three.

I got the 12v warning and the next day the car was dead. So while I can't say if there is a software issue or not - I would always take that warning seriously.

 

[stevedee]

...its another stupid software glitch which others less able to check out will be concerned about.

C’MON MG get these little issues sorted!

I'm not getting these problems, but I'd be interested to know if your software version is the same or different from mine;

Thread 'MG S5 software version thread' MG S5 software version thread

If your version is different, it could be software.
If its the same, then it doesn't prove anything either way.

EDIT: sorry, I can't get the link above to 'stick'

 

[LenEV2016]

I'm not getting these problems, but I'd be interested to know if your software version is the same or different from mine;

Thread 'MG S5 software version thread' MG S5 software version thread

If your version is different, it could be software.
If its the same, then it doesn't prove anything either way.

EDIT: sorry, I can't get the link above to 'stick'

It might not matter which software, as if it's like the mg4 infotainment software is separate to all the cars systems software

 

[Ian Key]

I have no idea whether an overnight drop of 0.3v is or is not significant?

That could be caused by a drop in the ambient temperature.

 

[emmrecs]

That could be caused by a drop in the ambient temperature.

Thanks! That seems to be confirmed by the reading this morning (ambient temperature very close to 0) of 12.3.