Smart charging(not so smart)

AlS3BE

Registered User
Quick questions for those with the skills.
Currently not doing a huge amount of miles and the battery is hovering around 30-40% charge according to vcds and my mates battery tester. Battery tester says health of battery is 100%.
even after an hour drive it’s not much more than 50%. the other weekend was out for a 2-3 hour drive it didn’t get much more than 60%.
I reckon the smart charging system is keeping this low, maybe too low, for efficiency purposes. Worse thing is if I don’t use the car for a few days or a week it drops to 20-25% charge and occasionally I get a low battery warning on dash. Dashcam only works for a couple of hours after parking and it’s should go on for a couple of days if the battery had more charge.
is there a way to code the module so the car charges the battery to a higher level?
 

Audi-Sport-Driver

Active Member

Causes of Battery Drain​

There are things in contemporary vehicles that drain the power of your vehicle without knowing. They are called parasitic drains. Vehicles with plenty of gadgets and computers will stay for less than four weeks before the battery dies. This is because they will be getting power from the car battery even when it is off. This is why batteries lose charge even when the car is sitting. The life of a battery is difficult to predict. It will depend on the climate and also the age of the battery.
 

AlS3BE

Registered User

Causes of Battery Drain​

There are things in contemporary vehicles that drain the power of your vehicle without knowing. They are called parasitic drains. Vehicles with plenty of gadgets and computers will stay for less than four weeks before the battery dies. This is because they will be getting power from the car battery even when it is off. This is why batteries lose charge even when the car is sitting. The life of a battery is difficult to predict. It will depend on the climate and also the age of the battery.

I understand/know that.
My question was the smart charging system is not letting the battery go above a certain charge state and I want to increase this. Currently even with a new battery the battery doesn’t ever charge above 60-65%, I know it won’t do 100% cause there needs to be room for things like regenerative braking but I want it to be higher than what it currently is.
 

Audi-Sport-Driver

Active Member
I understand/know that.
My question was the smart charging system is not letting the battery go above a certain charge state and I want to increase this. Currently even with a new battery the battery doesn’t ever charge above 60-65%, I know it won’t do 100% cause there needs to be room for things like regenerative braking but I want it to be higher than what it currently is.
If it isn't in menu probably not possible to do it ... Which car it is ? New 8Y ?
Don't think such new feature is in 8V ?
Best way is the connect your own charger and charge battery ?
 

Frizzley

Registered User
Questions would be
- how old is the battery /if it’s new was it coded correctly when it was put on the car
- have you checked your alternator- if a setting was causing the issue then it would be a common problem in similar vehicles rather than something specific to your own car
- the drop in charge over the period you describe suggests either a faulty battery or something that is drawing more current than it should. Stater for 10 would be the dash cam but if wired correctly that woukd not drain the battery that quickly.
- have you tried fully chargoing the battery using a char and then seeing how long that lasts.
- is your mates battery tester working correctly?
 

AlS3BE

Registered User
Questions would be
- how old is the battery /if it’s new was it coded correctly when it was put on the car
- have you checked your alternator- if a setting was causing the issue then it would be a common problem in similar vehicles rather than something specific to your own car
- the drop in charge over the period you describe suggests either a faulty battery or something that is drawing more current than it should. Stater for 10 would be the dash cam but if wired correctly that woukd not drain the battery that quickly.
- have you tried fully chargoing the battery using a char and then seeing how long that lasts.
- is your mates battery tester working correctly?

battery is under 2 years old. Was replaced under warranty by Audi so relatively new. Battery tester shows good cranking power so passes battery health test at 100%. State of charge however is always quite low.
not sure what to check for alternator settings as this was my question if there is any alternator coding that can be changed or checked.
I would say drop in charge is normal even with the dashcam as disconnecting it doesn’t make a huge difference. Dashcam is also set to switch off at 12.2v or 2 days whichever comes first.
the problem is when I do drive the car with maybe a long-ish distance drive once a week is the battery doesn’t charge to a high enough percentage, partly I think due to the smart charger for efficiency.
I had my dads(Toyota) car last week and the same battery tester showed that car was showing 40-50% state of charge and after 20minute drive it showed 90%+. Same journey in my car will increase my percentage by about 5-10% on a good day. The battery in the Toyota is a lot bigger than the one in the s3 and similar age.
it’s like it doesnt want to charge pass 60-65% even after a 2 hour drive so was seeing if there was some coding somewhere where it will let the car charge further.
I’ve had Audi check it a few weeks ago when it was serviced and they said the tests all came back fine for alternator and battery. I’ve had the battery on a bench at my mates and trickle charged and it gets to 90%+
It’s just when In the car the car lets it’s drop and maintains a low state of charge.
I don’t own a battery charger or want to connect/disconnect one every time I drive the car as there will be that one time me or the mrs takes the car away while it’s still connected and cause some damage.
 

JohnM100

Registered User
VCDS Map User
Gold Supporter
I suspect your battery is on its way out - recall you had one replaced under warranty when the car was about a year old? Did they put another Moll EFB in it?

Have you looked into what the car thinks the usable capacity and internal resistance are? It will adapt charging accordingly. When mine went, the car measured usable capacity as 8Ah so it would only charge to about 6Ah, and that goes to zero fast, compared with a new 70Ah battery. From memory, measuring blocks 18-20 in 19 CAN gateway.

Might be worth just changing the battery serial number in VCDS so it re-learns the battery charging behaviour, but if the battery is really on its way out, that might overcharge it.

AGM batteries cope with being left partially charged much better then EFB+

Edit: saw your previous reply - I was typing this post at the same time
 
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AlS3BE

Registered User
I suspect your battery is on its way out - recall you had one replaced under warranty when the car was about a year old? Did they put another Moll EFB in it?

Have you looked into what the car thinks the usable capacity and internal resistance are? It will adapt charging accordingly. When mine went, the car measured usable capacity as 8Ah so it would only charge to about 6Ah, and that goes to zero fast, compared with a new 70Ah battery. From memory, measuring blocks 18-20 in 19 CAN gateway.

Might be worth just changing the battery serial number in VCDS so it re-learns the battery charging behaviour, but if the battery is really on its way out, that might overcharge it.

AGM batteries cope with being left partially charged much better then EFB+

Edit: saw your previous reply - I was typing this post at the same time

will have a look later at the usable capacity. Can only assume an Audi dealer will fit and code a new battery properly. If I decide to keep the car I will probably replace with an AGM as they are meant to be far superior to the efb type batteries.
 

alpesh26

Registered User
Quick questions for those with the skills.
Currently not doing a huge amount of miles and the battery is hovering around 30-40% charge according to vcds and my mates battery tester. Battery tester says health of battery is 100%.
even after an hour drive it’s not much more than 50%. the other weekend was out for a 2-3 hour drive it didn’t get much more than 60%.
I reckon the smart charging system is keeping this low, maybe too low, for efficiency purposes. Worse thing is if I don’t use the car for a few days or a week it drops to 20-25% charge and occasionally I get a low battery warning on dash. Dashcam only works for a couple of hours after parking and it’s should go on for a couple of days if the battery had more charge.
is there a way to code the module so the car charges the battery to a higher level?
Sounds similar to the issues I've been having with mine - especially with the dashcam. I go into the office twice a week which is a 40 mile round trip but this isn't enough to maintain a decent amount of charge so I'm getting weird problems like my cruise control deactivating itself and the alarm going off without anything obvious triggering it.

For mine, the battery itself is OK, the car just isn't getting enough use so I've been putting it on charge with my CTEK charger to keep it happy, this could be an option for you. If you haven't got a charger, I'd recommend a CTEK. It has a battery restoration function so you could try that also.
 

AlS3BE

Registered User
Sounds similar to the issues I've been having with mine - especially with the dashcam. I go into the office twice a week which is a 40 mile round trip but this isn't enough to maintain a decent amount of charge so I'm getting weird problems like my cruise control deactivating itself and the alarm going off without anything obvious triggering it.

For mine, the battery itself is OK, the car just isn't getting enough use so I've been putting it on charge with my CTEK charger to keep it happy, this could be an option for you. If you haven't got a charger, I'd recommend a CTEK. It has a battery restoration function so you could try that also.
Was trying to avoid getting a charger and maybe get the car to charge itself to a higher level. It’s probably more in the morning if the weather is bad and I drive the kids to school instead of walking I will end up driving it away with the charger still plugged in and end up breaking something.
Ctek is meant to be the best out there. That’s the one I used to test on a bench. Mate runs a garage and he swears by them.
 

alpesh26

Registered User
The CTEK MXS 5.0 comes on offer on Amazon quite often. I went with the MXS 7.0 for future proofing but not sure how useful it will be in the future with cars going electric
 

Harvey

VAG Convert
For a decent no fuss great price battery charger/maintainer (can be left connected) I'd recommend the Maypole MP7423, cheap from Amazon click me

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AlS3BE

Registered User
What do you guys do when you got the charger plugged in?
Do you arm the car alarm or just lock the doors. Would have thought the fancy electronics would think something is up if the voltage/current changes in the car while it’s armed.
 

alpesh26

Registered User
What do you guys do when you got the charger plugged in?
Do you arm the car alarm or just lock the doors. Would have thought the fancy electronics would think something is up if the voltage/current changes in the car while it’s armed.
I've had no issues with it plugged into the charger and locked.

Personally, I wouldn't leave it unlocked as this is likely to cause problems with an insurance claim if the car gets stolen/something happens...don't want to give them the excuse to not pay out
 

JohnM100

Registered User
VCDS Map User
Gold Supporter
Charge in situ with -ve clamped to earthing point and +ve to the battery terminal so the car can monitor how much is going into the battery.

I lock the car and the cable is thin enough to come out between the headlight and bonnet without being crimped.

I use the CTEK optional extra wiring loops so it’s installed permanently and just tuck the fly lead behind the battery when not charging.

The MSX 5.0 is the charger everybody raves about but I went for the Time To Go 5 as it’s AGM mode does not have the high voltage desulphation spike that is still done by the MSX 5.0 even in AGM mode. AGMs don’t like or need that spike.
 

Harvey

VAG Convert
What do you guys do when you got the charger plugged in?
Just carry on as you do without a charger plugged in and lock and arm your vehicle. I use an Accumate which have been out years, no fancy digital display and just does what it says on the tin and maintains the vehicle battery in a healthy and charged condition. Used it on all sorted of battery variants/amps and just works.

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