Battery condition.

[martin j.]

Wife managed to leave the lights on last week for several hours,-it was on auto, I’m sure- battery shows 50%, stuck on the charger and when charger showed complete dash only showing 70%, after a week of running it has peaked st 80%, does sound ok for a 2015 car?

 

[RUM4MO]

When things are left to the smart charging in the car, I don't think it will get above 80% as the car's smart charging system needs somewhere to "dump" the "regenerative braking" energy.

 

[RADIOTWO]

Wife managed to leave the lights on last week for several hours,-it was on auto, I’m sure- battery shows 50%, stuck on the charger and when charger showed complete dash only showing 70%, after a week of running it has peaked st 80%, does sound ok for a 2015 car?

Hi Martin, confused with your comments: Wife managed to leave lights on "It was on auto" Leaving on Auto does not leave lights on (With key out) and where on dash does it show % of battery ? of have i missed the whole point!

 

[black_sheep]

With key in ignition and lights on auto in a garage, then lights would be on - this is why car normally has lights in ‘0’/off position when it’s been in for service. With ignition off, the electrics switch off after ‘x’ minutes.

Battery SOC (state of charge) can be checked as follows:

 

[martin j.]

Sorry, the lights on auto comment was my wife’s excuse, they were not, but in the headlights position, it’s never her fault. State of charge checked as per above video.

 

[martin j.]

When things are left to the smart charging in the car, I don't think it will get above 80% as the car's smart charging system needs somewhere to "dump" the "regenerative braking" energy.

Ta. Just wondered if if it was indication of the battery showing it’s age.

 

[RADIOTWO]

Sorry, the lights on auto comment was my wife’s excuse, they were not, but in the headlights position, it’s never her fault. State of charge checked as per above video.

Hi again, ok on the switch! and ref the state of charge I have the Virtual cockpit and don't have the button to check, but I would check with a "drop tester" to see the state of the battery

 

[RUM4MO]

Ta. Just wondered if if it was indication of the battery showing it’s age.

By its self, I don't think that you can rely on that as an indicator of dying battery, the only way to work out the general health of the battery is to check its fully charged voltage, check its ability to deliver current and check its present amp hour capacity. The first one can not be checked while it is only being re-charged by the car's smart charging system, the second can be checked by anyone having a suitable battery tester, even a cheapish CTEK one that is designed by Midtronics who are the standard for this sort of thing, the final check, checking its amp hour capacity would need you to apply a sensible or correct load and discharge it through this.
Once you have gone down the road of suspecting a car battery that is an EFB and is over maybe 4 years old, I think your only option to escape from this way of thinking is to replace the battery.
My under used 2011 Audi S4 still has its original factory fitted AGM battery, I think that 10 years is enough for that battery and I've bought a Bosch replacement, I've tested it with a voltage meter when fully charged by an external CTEK charger, I've tested it using my CTEK battery tester, and so I know that it "looks as good as new", but I don't have a proper load to discharge it into to, so for me, I'll be replacing that apparently "still good" battery, maybe a stupid waste of money, but hopefully I'll be looking forward to the next 5 or more years without any battery worries.

Edit:- what I should have added is, if while using that car regularly on average length journeys, you notice that auto stop/start is not being available, then it might be time for a new battery, and maybe an upgrade to AGM from EFB from a sensibly priced online supplier.

 

[martin j.]

I have access to a battery condition tester at friends garage so will try that next time I’m there, just being lazy and thinking I could use the on board display, Ta all.