Strange battery charging voltage?

[CupraTOC]

I have a 2017 Leon ST (1.8TSI). Had the obdeleven on live data whilst driving and noticed that the alternator seems to charge around 13.2V whilst using gas pedal and if I lift off goes up to a 14.4v charge. Same pattern everytime.

I know there is some smart electronics in these newer cars but is this normal? I'm used to older cars giving the battery a constant charge of just over 14v.

 

[RUM4MO]

Absolutely, the charging plan nowadays is to minimise charging under normal conditions unless the battery really needs it, and leave the charging until it comes by way of "wasted energy" ie when the car is on the over run and braking.

I think the aim is to always have some spare capacity for "dumping free charging" into the battery which means a well charged battery will normally be at max at 75>80% charged. It will always be able to restart the car though.

 

[CupraTOC]

Absolutely, the charging plan nowadays is to minimise charging under normal conditions unless the battery really needs it, and leave the charging until it comes by way of "wasted energy" ie when the car is on the over run and braking.

I think the aim is to always have some spare capacity for "dumping free charging" into the battery which means a well charged battery will normally be at max at 75>80% charged. It will always be able to restart the car though.

Got ya! So that's why when I'm playing with obd with just ignition it doesn't take long before it shows battery full to discharging. May also explain why there seems to be a common failure of batteries within a two to three year from new as constantly only charging up to 80% capacity cannot be too good for the battery long term.

 

[RUM4MO]

Actually, these cars with start/stop etc should only ever get fitted with EFB batteries or AGM batteries and it is claimed that both can tolerate that sort of use.
Where the proper abuse comes in is when a car is used only frequently and for short journeys.
My wife's 2015 VW Polo 1.2TSI 110PS gets used at least twice a week on 10+single journeys, during lockdown it was connected up to a smart charger - CTEK MSX 5, and its battery still checks out as being quite healthy - I have a CTEK battery tester and that gives a "capacity" measurement in CCA. My car is a 2011 Audi S4 and it tends to be grossly underused but is always connected to another CTEK 5 test and charger - its battery is now over 10 years old and still appears/tests as being quite healthy, although at this age I've bought a new battery as 10 years in my world is good enough and I don't want to end up with battery failure if and when away from home with that car.
The charging setting will be slightly different for an EFB and a AGM and once a change of battery is logged into the car, including battery type, that will get taken care of.

 

[CupraTOC]

Actually, these cars with start/stop etc should only ever get fitted with EFB batteries or AGM batteries and it is claimed that both can tolerate that sort of use.
Where the proper abuse comes in is when a car is used only frequently and for short journeys.
My wife's 2015 VW Polo 1.2TSI 110PS gets used at least twice a week on 10+single journeys, during lockdown it was connected up to a smart charger - CTEK MSX 5, and its battery still checks out as being quite healthy - I have a CTEK battery tester and that gives a "capacity" measurement in CCA. My car is a 2011 Audi S4 and it tends to be grossly underused but is always connected to another CTEK 5 test and charger - its battery is now over 10 years old and still appears/tests as being quite healthy, although at this age I've bought a new battery as 10 years in my world is good enough and I don't want to end up with battery failure if and when away from home with that car.
The charging setting will be slightly different for an EFB and a AGM and once a change of battery is logged into the car, including battery type, that will get taken care of.

Well my original factory fitted battery died after two years and have read many issues with the factory fit batteries failing early. Have now fitted a Halfords advanced AGM stop start and changed the setting in OBDeleven to glass mat. So far so good and hopefully this will last a fair few years as car gets used on 12 mile journey daily .