Battery on the blink already?

[lastgasp]

A couple of weeks back, my Kamiq, three and a bit years old, + 16k miles, started giving a 'Low Battery' warning.  I wasn't unduly alarmed as it had not been used much recently and the bad weather inevitably had meant a heavy demand on the electrics.   I put it on charge overnight and next day all seven indicator lights on the C Tek charger were lit and the warning had gone.  That day, when the Stop/Start kicked in, I realised that I could not recall it operating for quite some time, a sure sign that the battery had been low.  So, all was now well!

 

Yesterday, after quite a long run (without any extra electrics switched on) I suddenly twigged that the Stop/Start was not coming on.  Today the rested battery is giving a reading of only 12.16v. I have put it back on charge and this time I will note the reading after the charge is completed.

 

What does the hive mind think?  Surely it's a bit early for the battery to fail, or could it be an alternator issue?

[Paws4Thot]

20 minutes ago, lastgasp said:

Surely it's a bit early for the battery to fail

No; this is a typical lifespan for this type of battery.

[MickA]

My stop/start Toledo's battery (heavier duty) lasted around 5 years before giving trouble. I've learnt a lesson there, now over winter if the car isn't used much I keep a check on the battery condition and put it on a trickle charge. 

Not using the car much in winter caused the battery to basically not hold a charge for long, yes it would start the car but with all systems on it soon drained the battery throwing up an array of warning lights.

New battery fitted and kept topped up when necessary has made sure it's doing it's job, now around 4 years old.

[lastgasp]

Thanks both - quick replies too.   So,  cars get 'smarter',  battery life gets shorter - ain't progress wonderful.

 

It's got to go through the C Tek cycle now, so out of interest tomorrow I'll check the rested voltage and also the charging voltage. 

 

For convenience I'll most likely get a DIY battery delivered from Tayna and get a nearby VAG independent to re-programme the system  -  but, just out of curiosity, does anyone know what the dealer would charge for battery replacement?

[rum4mo]

If the battery is an EFB, why don’t you run the “reconditioning” charging program. I’ve done that once a year on the original EFB in my wife’s 2015 Polo 1.2TSI and and it does improve the battery’s health - ie its CCA as measured using a CTek battery tester.

 

To be honest, I’m almost annoyed how well this original, ie factory fitted Exide EFB is behaving 49k miles and 8.5 years from new, but in reality, a car’s battery life tends to be linked to how a car gets used - not intended as a criticism, just the way it is.

[J.R.]

The voltage you have measured is typical for the BMS (under) charging regime especially when the battery has aged slightly.

 

If you disconnect the shunt resistor it will revert to a standard charging profile, you will lose the start/stop facility (win-win in my book!) and could well get another 7 years life out of the battery, it will start the car without giving you all these warnings, when it becomes sluggish and reluctant to do so that will be the time to think about replacing it.

 

Just how things always used to be................................

[lastgasp]

Thank you for your responses.  Food for thought there.  If I can make the time, I will look at it more closely.

[sandal farm]

Where is the shunt resistor and what does it look like thanks

[sussamb]

On 06/03/2024 at 20:31, J.R. said:

 

If you disconnect the shunt resistor it will revert to a standard charging profile, you will lose the start/stop facility (win-win in my book!) and could well get another 7 years life out of the battery, it will start the car without giving you all these warnings, when it becomes sluggish and reluctant to do so that will be the time to think about replacing it.

 How do you do that as if simple it sounds like we should all do it, I switch off stop/start everytime I start the car anyway so no loss there

[J.R.]

In parallel with one of the main battery leads,  functionally it could be either, I think its the negative because of the warnings to use a battery charger on the earth stud not the battery negative terminal.

 

I cant do any more than describe because thankfully my car is just old enough to not have stop/start and a battery mismanagement system.

[Warrior193]

1 hour ago, J.R. said:

In parallel with one of the main battery leads,  functionally it could be either, I think its the negative because of the warnings to use a battery charger on the earth stud not the battery negative terminal.

 

I cant do any more than describe because thankfully my car is just old enough to not have stop/start and a battery mismanagement system.

The sensor lead is a small plug-in tag attached to the negative battery terminal.

[sussamb]

So is it as simple as removing that?

[Warrior193]

Yes, apparently so if you want to disable the smart charging function. Personally I have left mine connected to allow use of regenerative charging when it is available. What the sensor lead does is to restrict battery charging from the smart alternator to around 75% - allowing head space in the battery capacity for regenerative charging during throttle-off overrun and braking.

[sussamb]

Didn't know the Kamiq had that!

[J.R.]

"Smart charging", now there is an oxymoron if ever there were one!

[lastgasp]

Update.

 

The 'low battery' warnings continued with ever-increasing frequency despite further attempts to recover it with the C-Tek,  so I decided to replace it.  I had planned to DIY  but a recurrence of my back problems made that a bit problematic.  So, today I went to an independent VAG specialist who swopped the battery (I never determined what brand it was) for a Yuasa.  

I now have peace of mind but I am still  a bit miffed that the original battery - to my mind - had such a short life.

[nta16]

Like many owners, particularly of later / latest models, as the engine started and the lights seemed bright enough you missed the driver's warning sign of low battery with the start/stop being inoperative, that was the time to charge the battery, preferably with an appropriate charger maintainer following the instructions in the Owner's Manual and for the charger.  Unfortunately by the time you got the 'low battery' warning the battery had had too much use, abuse and neglect for your C-Tek to recover it.  Once a battery gets too low it never fully recovers even if it continues to work and carry on.

 

On the plus side you seemed to have missed the other possible unexpected issues, error codes, warning lights and messages that other have reported with continued use of the car with a battery in poor state of charge / health.

 

These modern cars have a lot of convenience high consumption electrical items and lots of computers and programs that only run on 5v so you don't want your battery too low for them.  The higher heat of the summer effects the battery as well as the cold of winter so battery charging isn't just about winter car/battery use, or lack of use.

 

5k-miles per year is low mileage meaning the car's alternator may not be able to keep up with the car's and battery's use - the answer is preventative charges, in this case certainly with an appropriate charger maintainer or having the maintainer on the battery when the car is not in use for a while.

 

If you want your new battery to last longer then you can help it with preventative charges.  My mate has a couple of identical expensive C-Tek chargers and they gave different performance to each other when used on his two vehicles and yours is the second instance just recently where I've read of a C-Tek hasn't recovered the battery but then a cheap "smart" charger might have also failed, as said these "smart" chargers ain't that smart.

 

From the 2020/07 Owner's Manual. - https://manual.skoda-auto.com/004/en-com/Models

 

Edited 4 April by nta16

[lastgasp]

nta16

 

Thanks for that. Food for thought.