Battery issues and Auto Stop/Start not working

[RIncewindwiz]

Interesting stuff and thank you (I've an engineering degree and so the sort of odd mind that finds this stuff interesting!)
Cant do this until tomorrow as I am about and about for the rest of the day.
Will do Thu morning and report back

[varooom]

No rush my side, and at 9 months your end... a few days won't matter.

Best of luck, maybe something will jump out at you from the documents.

[nta16]

Please note - I am not a mechanic or expert in anything.

 

3 hours ago, RIncewindwiz said:

Charger can be found here
https://www.amazon.co.uk/Matthew00Felix-FOXSUR-Repair-Charger-Motorcycle/dp/B07W6HGMXW

Thanks, I saw ones like that but a different model number.  My only thought is it seems to sell in USA particularly at very low prices and being made in China, as are the more expensive chargers, I wonder about the lack of quality control from manufacturer which means tens, hundreds of thousands are probably good but some are not.  Recently a set of 5 "classic" car and bike owners bought a £15 charger from Lidl one was faulty out of the box.  Your charger might be fine but you could check it in use.

 

 

2 hours ago, RIncewindwiz said:

Readings taken at chassis earth differ by 0.01V from those at battery terminal

Internal readings (taken earlier) at the cigarette lighter appear to be 0.2 volt lower

As you probably know the variances in the different instruments doesn't matter as long as they remain consistent.  You probably also know you should test the testing equipment before each test or set of test to confirm the testing equipment remains within tolerance and often this includes the tester (especially if it's me).

 

 

3 hours ago, RIncewindwiz said:

Start Stop didn't work yesterday after what should have been 30 mins on a motorway and turned out to be an hour on back roads!!!

Often just driving the car isn't enough to sufficient recharge the battery enough especially if the battery charge has been taken too low before the drive, potentially the drive could deplete the battery even more it depends on the outgoings and any income.

 

Taking into account what varooom has put I say you should check the battery at the terminals after 12 or more hours after recharging or a couple of hours later but turn the headlights on for 30 seconds to drop the surface charge.

 

Again the system you use is less important than being consistent with it, if the battery was off the car it'd be easier but after charging a reading at 12 and 24 hours later would let you know how much of the charge the battery has held.

 

As you'll find there are a few factors involved with the figures so you do get different tables with slightly different figures but generally it's easy to see when things are good and when not.

 

 

3 hours ago, RIncewindwiz said:

I happened to notice at one stage the battery charger said it was putting out 1.8A but its a 70Ah battery so up to 7A is OK?

The thing is it depends when the 1.8A was (and how accurate that display reading is) but yes according to VW a 70Ah battery wants a 7A or lower charger but don't get too hung up with having 8A.  My experience is that a lower slower longer recharge gets into the battery better and lasts longer and as far as I can see this is backed up with what I've read more recently.

 

The thing is many people now don't have much stocks of time and patience so think higher, quicker, faster is better when often it isn't.  For many years now I've been using a about 1.2A smart charger and maintainer for batteries in a low state of charge and well down on state of health and that with a large battery disconnected from the car could take up (sixty) 60 hours to fully recharge the battery.  Usually it'd take less than two days but there's not so many people willing to allow that long to retrieve the battery.  I've had two failures, I notice the latest version of the charger has that it can work on a 12v battery when it's as low as 3v many modern chargers used to give up at less than 6v.

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

I was told about the following site a few weeks ago, I've not looked at it too much as all the adverts annoy me but I did read on site or download (I forget) a couple of articles that seemed useful. - https://batteryuniversity.com/

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

@RIncewindwiz I might as well put it, as you've got a VCDS this is what I suggest, check your (Owner's Manual) "Operating Instructions" for what might need resetting after disconnecting and reconnecting the car's battery (often it's not as listed if you've closed the electric windows and roof, just the time of day clock) and disconnect the battery from the car and fully recharge it with a 4-amp or lower appropriate charger and maintainer.

 

Personally this time of year I'd remove the battery from the car and charge it in the spare room for higher and more consistent ambient temperature and more convenient to monitor progress.

 

On reconnecting the battery you can 'recode' as if replaced and remove any error codes that might be in the systems.

 

ETA: I'd then keep an eye on the battery and do preventative recharges, as required, with the battery connected to the car.  As routine I'd check and charge at the time when winter tyres would be fitted and then again when they would be removed and a third time after very hot temperatures of the summer.

 

This is the 4-amp charger and maintainer I bought last month, there are other makes and suppliers available, just an example, I got it for £23.49 off eBay, other suppliers and prices available of course.  The one I have, Ring RSC 804 - 4A Smart Battery Charger & Maintainer -https://www.ringautomotive.com/en/product/RSC804

 

There's also a 6A version - Ring RSC 806 -  6A Smart Battery Charger & Maintainer - https://www.ringautomotive.com/en/product/RSC806

 

RSC804_RSC806_RSC808_Instructions (1).pdf

 

 

RSC804_Spec (1).pdf

 

RSC806_Spec.pdf

 

Edited 25 January, 2023 by nta16
ETA:

[RIncewindwiz]

8 hours ago, varooom said:

What I would recommend is to charge again your battery, and check voltage at the end of the charge cycle directly on battery terminals.

Then wait two hours, unlock car, open bonnet and again check voltage quickly, some control modules will be awake, but will give you a rough SOC.

 

 

So the following readings (multimemter between battery terminals)
Before charging   12.3   (back 30 mins previosuly from 10 mile drive)
Charger finished  12.6

10 mins later        12.25  (time taken to put everything away)

2 hours later        12.18

Edited 25 January, 2023 by RIncewindwiz

[varooom]

3 minutes ago, RIncewindwiz said:

So the following readings (multimemter between battery terminals)
Before charging   12.3   (back 30 mins previosuly from 10 mile drive)
Charger finished  12.6

10 mins later        12.25  (time taken to put everything away)

2 hours later        12.18

I get 12.3v leaving my car for a whole week in freezing cold for reference.

[varooom]

Take a read of this thread in full, and you will see my voltage graph, and @DuncanDisorderlygraph also, see if you can do this graph with your VCDS when you next do a start-up.

 

If your alternator is putting out the right levels, then your battery is not too healthy (might be idea to get a load test done on battery).  Your battery might still be ok for another 2-3 years for all we know, but best tested out.

 

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

37 minutes ago, RIncewindwiz said:

Before charging   12.3   (back 30 mins previosuly from 10 mile drive)
Charger finished  12.6

How long was the charger on the car to get from the 12.3 start to 12.6 finish and what signified the finish and wahat was used to give the figures?

 

On a side note do you have anything plugged into the 12v socket?

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

If you lived nearer we could put on my neighbour's spare/second old diesel van battery, that I brought back to use and we've been charging and alternating use with the newer battery he bought to replace it since before Covid IIRC, on his barely used van.

 

Then we could test your car's alternator function with his Ring tester, not reconnect the battery monitoring start/stop as your losing nothing, you code in for standard battery and I'd see what I can recover on your Yuasa YBX9096 given time.

 

The Yuasa should be a good battery so if it's only a couple of years old it might be able to get more proper use out of it for a while, if not we'd discover with charging and testing.

 

Yuasa's website downloadable for the YBX9096 shows "Recommended Charge Rate 4A", I'd forgotten this but it is only a recommended. - https://www.yuasa.co.uk/batteries/automotive/ybx9000-agm-batteries/ybx9096.html

 

YBX9096_DATASHEET.pdf

 

Edited 25 January, 2023 by nta16
spelling

[RIncewindwiz]

8 minutes ago, varooom said:

I get 12.3v leaving my car for a whole week in freezing cold for reference.

So it looks like a ropey battery?

 

[varooom]

Just now, RIncewindwiz said:

So it looks like a ropey battery?

I mean it doesn't look great no, but AGM's can be "on the ropes" and still come back for a few more rounds.

Right now I would try a few more charge cycles and see how you get on with it, taking the readings at the end/after 2hrs/next day as appropriate.

 

It might be a good idea to do the logging of the Voltage in VCDS when you start the car, like I did to see what is going on (if you cannot make the pretty graph, at least grab the RPM/Voltage log)

[RIncewindwiz]

15 hours ago, nta16 said:

Please note - I am not a mechanic or expert in anything.

 

How long was the charger on the car to get from the 12.3 start to 12.6 finish and what signified the finish and wahat was used to give the figures?

 

On a side note do you have anything plugged into the 12v socket?

 

Charger on car for < 2 hours (I looked after 2 hours and it was fully charged)
Plugged into 12v - Only a GPS watch

FYI I sent Yuasa the charging readings and they replied

12.58v would not be a reading we would see for a fully charged battery. If it is dropping to 12.18v after a short period of time, that would suggest that the “surface charge” is dissipating leaving a voltage figure of less than 50% state of charge.

This could suggest that the battery is deeply discharged and very likely sulphated.( Which would explain why the battery is not reaching a full charge- the ability to store charge is reduced by the build-up of sulphur on the battery plates) The lifetime of any battery would be reduced if it subjected to frequent use at a low state of charge.

Testing the CCA reading using an appropriate tester would confirm if the battery were indeed sulphated.

On the basis of comments here (thanks to all that have contributed) and from Yuasa, I am inclined to give up and get a new battery.

[varooom]

29 minutes ago, RIncewindwiz said:

On the basis of comments here (thanks to all that have contributed) and from Yuasa, I am inclined to give up and get a new battery.

Understanding really, you want to have peace of mind that it will work on the turn of the key.

 

 

Shop around, as batteries have been hit with the oh so wonderful inflation

https://www.tayna.co.uk/car-batteries/types/096-agm/

https://batterygroup.co.uk/batteries-power-electronics/agm-batteries/9483/varta-start-stop-silver-dynamic-agm-e39-12volt-70ah-760a/en-570-901-076-starter-battery-096?number=110058

 

I took off my factory fitted Varta after 7 years (it was not fully dead, but not happy) and fitted a Varta E39 you can see on the above list, as whatever is inside must be good to live that long IMHO.

Edited 26 January, 2023 by varooom
Additional Information

[nta16]

Please note - I am not a mechanic or expert in anything.

 

15 minutes ago, RIncewindwiz said:

On the basis of comments here (thanks to all that have contributed) and from Yuasa, I am inclined to give up and get a new battery.

Yes I think it might be best for you and I'd suggest you perhaps also considered a new 4-amp smart charger for the new replacement battery.

 

The AGMs do run at lower voltage more happily and will show lower figures on the VW start/stop cars in normally use.

 

I was going to put you'd need to ask Yuasa if the 4-amp charging they recommend was for bench charging of retailers stock or for end retail customers during the battery's life.

 

Your present battery might be able to be revived for other than use on your car - or about £8 recycle value at least.

 

Also I've no idea what electric a GPS watch uses but any low use if constant adds up, it's like items on standby in the home or a small water leak in home they turn the meter very slightly but constantly so add to your bill at the end of the month, quarter or year.

 

When you get the new battery check what charge is in it and consider topping it up before fitting if you want a fixed starting point.

 

Good luck let us know how you get on, don't forget to 'code' the new battery and clear any error codes to start fresh at that point.

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

1 hour ago, RIncewindwiz said:

So it looks like a ropey battery?

It is now but that's due to circumstances I'd not let that put you off considering again as it's own replacement if you wanted.

 

[Nirrain]

For what it is worth I have been going through a similar experience: Rare start/stop and very quickly degrading battery voltage while parked (12.6 to 12.2 in the span of a few days), albeit with an EFB battery.

 

My 2Amp 'smart charger' reports the battery as full after a few hours of charging despite 12.2->12.6 should be 60%->100% SoC so should take many hours on a 2Amp charger.

 

After gathering input on reddit for this issue I tried to leave the charger on the battery in maintenance mode (13.5-14V current limited charge mode) for 48 hours even though it was already "full" which seems to work.

 

My working theses is therefore that the surface charge (possibly due to Stratification, though that should not be so relevant for AGM batteries) causes the charger and onboard BMS to think the battery is full when it is not, and even though the battery does not accept much current in this state, it does still accept a little and is therefore gradually being filled closer to true capacity instead of just surface charge. 

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

39 minutes ago, Nirrain said:

My 2Amp 'smart charger' reports the battery as full after a few hours of charging despite 12.2->12.6 should be 60%->100% SoC so should take many hours on a 2Amp charger.

Hi. welcome.

 

Yeah it's like other "smart" devices they're not really that smart so sometimes you have to fool them into being smarter that's why diligent use of my old chargers often gets better results on batteries that are in not such a good state (of charge and health).  It also depends on what the smart battery charger is designed to do.

 

For readings different electronic devices will give you different readings and in different circumstances so always best to check them with another device.

 

Sometimes though through use, abuse or neglect (or accident) the battery or one of it's cells can be had it or too far gone and so the battery wouldn't be reliable or last long with use in a car.

 

Another reason not to fully trust the 'magic eye' or VW battery colours in the battery, my neighbour's battery that I've had to recharge for a few years now has the green 'magic eye', one time  it disappeared after I fully recharged the battery to only return after I fully recharged it the next time.

 

Because of the extreme hot weather we had last summer I expected to see even more reports than usual of battery "failures" this winter and this higher number will I think continue into spring and next summer because battery care got forgotten and steadily the complexity of the battery use has increased.

 

Edited 26 January, 2023 by nta16

[ords]

2 hours ago, varooom said:

Understanding really, you want to have peace of mind that it will work on the turn of the key.

 

 

Shop around, as batteries have been hit with the oh so wonderful inflation

https://www.tayna.co.uk/car-batteries/types/096-agm/

https://batterygroup.co.uk/batteries-power-electronics/agm-batteries/9483/varta-start-stop-silver-dynamic-agm-e39-12volt-70ah-760a/en-570-901-076-starter-battery-096?number=110058

 

I took off my factory fitted Varta after 7 years (it was not fully dead, but not happy) and fitted a Varta E39 you can see on the above list, as whatever is inside must be good to live that long IMHO.

I'll 2nd that as my Varta is 10 yrs old.

[ords]

1 hour ago, Nirrain said:

For what it is worth I have been going through a similar experience: Rare start/stop and very quickly degrading battery voltage while parked (12.6 to 12.2 in the span of a few days), albeit with an EFB battery.

 

My 2Amp 'smart charger' reports the battery as full after a few hours of charging despite 12.2->12.6 should be 60%->100% SoC so should take many hours on a 2Amp charger.

 

After gathering input on reddit for this issue I tried to leave the charger on the battery in maintenance mode (13.5-14V current limited charge mode) for 48 hours even though it was already "full" which seems to work.

 

My working theses is therefore that the surface charge (possibly due to Stratification, though that should not be so relevant for AGM batteries) causes the charger and onboard BMS to think the battery is full when it is not, and even though the battery does not accept much current in this state, it does still accept a little and is therefore gradually being filled closer to true capacity instead of just surface charge. 

 

Seems then it's best to take off one of the terminals if charging in situ, so there's no conflict with the BMS?

[varooom]

36 minutes ago, ords said:

I'll 2nd that as my Varta is 10 yrs old.

I was interested in seeing how far I could get with the original, but at the same time I also prefer not to get stranded.  I remember you saying 10 years, that's epic, and I think it should be cleaned up and put in a glass case for all to admire.

[Nirrain]

40 minutes ago, ords said:

Seems then it's best to take off one of the terminals if charging in situ, so there's no conflict with the BMS?

 

Interesting point, can you elaborate?

 

I presume the BMS has registered the battery as full since it does not charge the battery further even on a long 45+min drive. But if I do not bypass the BMS while doing a long trickle charge session in-situ my thought process is that if I charge the battery in-situ to full then I expect the BMS to consider the battery full afterwards (even if it also registered it as full prior) and all should be well? Or am I mistaken?

[Nirrain]

1 hour ago, nta16 said:

Hi. welcome.

 

Thank you!

 

53 minutes ago, ords said:

I'll 2nd that as my Varta is 10 yrs old.

My car came with a Varta EFB 59Ah which lasted only 3 years and the replacement Varta 70Ah Blue Dynamic started giving me problems after 1 year, so I have a different experience. That said if the long session trickle charge after the battery is full will restore the second battery I am left pondering if the first battery could have lasted longer if I had done the same back then.

[nta16]

Please note - I am not a mechanic or expert in anything.

 

31 minutes ago, Nirrain said:

My car came with a Varta EFB 59Ah which lasted only 3 years and the replacement Varta 70Ah Blue Dynamic started giving me problems after 1 year, so I have a different experience. That said if the long session trickle charge after the battery is full will restore the second battery I am left pondering if the first battery could have lasted longer if I had done the same back then.

To me this sounds like something is wrong, as with the OP here and another thread.

 

I'll give more details later if wanted but to me it sounds like the initial battery swap and or charging by car and/or battery charger.  I've got to go now but if you want to leave more details.

 

[ords]

2 hours ago, Nirrain said:

 

Interesting point, can you elaborate?

 

I presume the BMS has registered the battery as full since it does not charge the battery further even on a long 45+min drive. But if I do not bypass the BMS while doing a long trickle charge session in-situ my thought process is that if I charge the battery in-situ to full then I expect the BMS to consider the battery full afterwards (even if it also registered it as full prior) and all should be well? Or am I mistaken?

I just thought that if you have 2 smart devices connected there's potential conflict. If the battery is fully charged with one terminal disconnected, then the BMS should also read as fully charged when connected as you say.

 

However, some have said that in normal circumstances the battery is never 100% fully charged to allow for a small amount of regenerative current to be put into the battery