My, doesn't time fly! It doesn't feel like more than a few months since I bought my brand new 1.5 SEL in September 2018 nor since I was writing on these pages about the horrors of the engine dying and the kangarooing.

I'm pleased to say that I stuck it out and waited for the software fixes; I still find my Karoq the most comfortable car I've ever driven, and I've no intention of getting rid of it.

From what I hear, batteries seem to last for 7 or 8 years, with the occasional claim for significantly longer, and I guess that battery longevity is a 'how long's a piece of string' question.

My battery is the original Varta EFB and the car has done 41k miles; there is nothing currently (geddit?) happening to suggest that the battery is deteriorating in any way.

Has anyone on here had to replace their Karoq battery yet?"

Battery on our 2018 Karoq was still fine when we part exchanged the car for a new Karoq in March. This includes periods when it was left for a few months at a time while we were in France, always started on return without issue.

How long the 12v battery lasts depends on the driver's use of the car's electrics and how and when it is driven. To extend the useful life of the battery and potentially prevent all sorts of unexpected warning lights and messages, unseen error codes and issues, it is best to do full (100%, s/s VW only goes to about 80% by programing) preventative recharges with an appropriate battery charger maintainer (doesn't have to be an expensive one). Recharge by following the instructions in the car's 'Owner's Manual' and for the charger maintainer.

The engine not starting is only when the battery has been taken very low indeed well before that even if the headlights seem bright enough the battery can be in a too low state of charge for the computer systems that will then make you suffer with all all sorts of unexpected warning lights and messages, unseen error codes and issues. Loads of threads and posts for all the stop/start models on this site with the unexpected issues from having the battery too low for what the computers like.

Batteries are expensive and there can be the additional cost and hassle of 'coding' the new battery into the car's computer system.

A battery in good state of charge and health will help the car (and alternator) whereas one in a low state of charge and health can hinder in many ways. Number one reason for breakdown callouts is for battery and charging problems many of which would not have been the fault of the battery (or charging system).

HTH.

Edited 25 May25 May by nta16
typo

Interestingly i popped the intelligence charger on my battery today. According to the obd 11 it was down to 65% after a short town run. The charger said ot was “full” after only 30-40mins. That’s not a good sign to charge so quickly?

Depends on the run and what of all the various electrical items you and the car were using, amperage of charger and other stuff.

The chargers aren't intelligent (same as compters, AI, "phones", ect.) that's just marketing, they are extremely dumb just following programing.

You're looking at three lots of programs and hardware andhaving these interact so which of the combinations is correct, how much variance(s) in the stand alone and combined systems.

"Full" as measured how and to what, the existing capacity or original or program measurement of full, the battery might be as full as it can get now.

Don't get too hung up on exact figures, go back to more of the old idea of an anolgue gauge with a needle, say a fuel tank guage, able to swing to a few markings, rather than 100 percentage numbers, and by quick glance you can tell if it's in about the right place for ususual.

ETA: if the battery was installed at less than 100% charged when new, then the VW programming keeps it at around 80% most of the time then was the battery ever really full from when it was fitted to the car and what happens to the battery when it was new will affect the battery's life if only in a small way.

All cars are about compromises, and for VW (and others) some proven deciets and probably a lot of unproven and unknown deciets, best as an owner/driver to accept these as much as possible, not much you can do about the compromises many of them are necessary just accept some VW pretend care about emmisions and fuel economy at the sacrifice of some battery longity or turn off as many electrical/electronic systems as you can that you don't want or use and do preventative battery charging as I've put numerous times and in this thread.

If you are that concerned you can get monitoring for battery use and charging.

And then we've not covered the VW sotware and hardware errors and faults that may contribute to issues on the car and premature battery replacement.

Edited 17 May17 May by nta16
typos

What i noticed on the charger the amp draw started off at 6.5 amps and the charging voltage 13.5 according to the “ smart charger” . Over 30 mins the amps dropped quickly down to 1 amp and the charging voltage increased to 14.8v before it shut off registering “ full”. The battery ceased to accept anymore amps. I guess my concern was that if the battery charged from 80% to 100% in only 30 mins something can’t be right. I’m sure it would take a lot longer to charge from 80-100 . I have a 9 year old worn out AGM battery from my previous car . At rest it reads 12.37 v ( they are usually 12.9v when new) . If i put the smart charger on it it’s fully charged within 5 mins but drops back down to 12.4v in a few hours. But i know that battery is f****k .

I put the tester on my EFB afterwards. Voltage 12.9v and 530 amps out of 700 amps EN and “Replace battery “. The obd11 reads the battery state of charge 73%.

Edited 16 May16 May by Micky 32

I think that it is a good idea to check the battery's capacity once a year so that you can track its "wear out" and so try to avoid ending up sticking with a battery that is well passed its useful lifetime.

I've got a CTEK battery tester and so far I've believed the readings it gives me at service time, the replacing of the original EFB at the 10 years point was more down to me already having a "one size up" AGM waiting for its time in the car, than the original EFB battery reaching the "wear out" point in its life, although I had been given the "replace battery" for a few years before that, but auto stop/start, when left to do its thing, did still operate, and that original EFB never caused any known issues over its 10 years 56,000 miles of use in a 2015 VW Polo 1.2TSI 110PS 6MT.

Micky 32 don't go too strictly on figures alone, especially from battery tester Mystic Meg type life predictioins. As always with 100% (full) you have to ask 100% of what, in this case it might be 100% of available in battery or 100% charger satifaction perhaps . Like you've put the voltage figures are good but they don't, like my memory, retain as much as they previously did. That's why on a suspect battery you do further checks/tests. Repeatedly starting the car's engine whilst taking voltage readings can be a good real world indicator of the battery condition on the car the battery as fitted with all the usual drains from the car.

Yes I would expect my 4-amp charger maintainer to take many hours to get from 80 to 100% when charging it on the car but (without any real checks) to me our battery seems fine and I expect it coulkd last many more years of useful service with us and how we use and maintain things (and I do the very minimum maintence on the car as I can).

The Ring charger maintainer I use won't get to full ("FUL") on a battery not capable of it from the way the Ring is set up (and I believe it may accept to charge a battery as low 2v in charge). I'm not a fan of these (expensive) CTEKs though others say they're great and I know people that own them I just don't have the confidence in them as my mate had two of them identical and they gave different stage of lights when tersted on the same battery, perhaps a rare one off case but at the cost and my limited experience that puts me off, they seem more suited to the type of people that like Audis and that certainly ain't me but as always each to their own.

If you have an EFB battery you can often check it's 'water' (electrolyte) level in each of the 6 cells to make sure they are at correct levels and also see a bit the condition of the plates which will give you an idea of any damage of furred upiness reducing performance and make a decision about whether to replace that batterry. Check again after fully, or as far as it gets charging.

16 hours ago, Micky 32 said:

I put the tester on my EFB afterwards. Voltage 12.9v

How many hours after the charging had finished, was it directly to the battery terminal posts alone not the post clamps.

Up to you, if you believe your tester replace the battery now. Would 530 amps start your car in the coldest bit of winter with whatever electrics and electronics you and your car's computers run at those times, would you still have 530 amps available at that time anyway, how much lower could that figure go and still start your car and the battery still successfully run all the electruics and electronics you and the car's computers want at those times. Doctor Google sez 530 is 75.71% of 700 if that helps.

As I can no longer do even the very simple maths I was once capablke of I don't bother too much with all the figures and maths and anyway it's not all as strictgly straighnt forward as some of the simple maths, I prefer prevention and that sdaves what's left of my feeble brain for more importasnt matters than farting about with cars u nnecessarily. I've had decades of attendig to use/abuse/neglected batteries on some of my neighbours' cars and I often had to take the batteries out of the cars, where possiblle check each cell, and start with using my 30+ year old "dumb" (like me) charger with its needle guage and misaligned numbers and within minutes I'd roughly know how longer the chargiung might take and swap over to my 20+ year old "smartish" (I can't remember what they were called then, marketuing terms change over years) and then as it only has one light that no longer seems to change colour (unless turned off-n-on-agen) I mght finish with the Ring "smart" charger just to confirm "FUL" or not.

Wow, another long un, could cure insomnia.

Something strange going on with Skoda batteries - We have a 2022 Superb and a 2024 Karoq - the Superb battery was dodgy from the off and had to be replaced after a year or so, the Karoq is not great but it's never failed to start.

What I find interesting, and somewhat amusing, is everytime one of the vehicles is in for service at the dealership - I get the same advice -'your battery is OK but the charge is low, needs a good run else we can charge it for you, £39...!', not just my vehicles, being in earshot of all the handovers, many customers are told the same.

The Superb was in for service just recently so I had the battery on (CTEC) charge all night, State of Charge was 98% when I took it in, 5.15pm collected it and guess what, 'your battery needs charging'........

Whenever I do a check with a Topcon device, on either vehicle, the meter reads either 'Poor' or 'Replace'........both batteries are VW Varta EFB 720amp.

9 hours ago, Berisford said:

Something strange going on with Skoda batteries - We have a 2022 Superb and a 2024 Karoq - the Superb battery was dodgy from the off and had to be replaced after a year or so, the Karoq is not great but it's never failed to start.

What I find interesting, and somewhat amusing, is everytime one of the vehicles is in for service at the dealership - I get the same advice -'your battery is OK but the charge is low, needs a good run else we can charge it for you, £39...!', not just my vehicles, being in earshot of all the handovers, many customers are told the same.

The Superb was in for service just recently so I had the battery on (CTEC) charge all night, State of Charge was 98% when I took it in, 5.15pm collected it and guess what, 'your battery needs charging'........

Whenever I do a check with a Topcon device, on either vehicle, the meter reads either 'Poor' or 'Replace'........both batteries are VW Varta EFB 720amp.

I use a Topdon battery tester and it appears to give a reasonable indication of my 10-year old EFB.

I'm not convinced that VAG Smart Alternator strategy (75-80% max charge) is the ideal for best battery life on the majority of vehicles, particularly ones doing regular short trips.

I like the idea of intelligent charging limiting the alternator to 75% SOC for longer runs, using regenerative to top up the remaining capacity, but my ideal would be for the charging algorithm to modify its program when logging regular short trips so that the battery is kept as close to 100% as possible.

Be interesting to know how much the VAG alternator/stop,start,/emmissions fuel saving lip service computer program actaully add on a long, congestion free motorway run add above the 75%-80% as the assumption is it'll be a lot and I'm not so sure about that, how much 'coasting' and braking is actually done if yournot constantly driving up the tailpipes of the vehicles in front and having your brake lights like dico lights.

@Micky 32 apollogises in all my rambling I forgot to put perhaps your battery is bunged up or had it and unable to take more charge but if so I'm a bit surprised your charger doesn't indicate this, by perhaps never showing full/100%.

11 hours ago, Berisford said:

Something strange going on with Skoda batteries - We have a 2022 Superb and a 2024 Karoq - the Superb battery was dodgy from the off and had to be replaced after a year or so, the Karoq is not great but it's never failed to start.

Perhaps there might have been, are, will be, an odd or perrhaps batch of bad batteries but in my experience this would be rare, IMO much more likily bad computer programing for the charging of the batteries but I'd not expect the car manufacturers to admitt this including VAG, who have been proved in court to be liars previuosly. Obviously once the "bad", or genuinely bad, batteries are used on the VAG and then removed it is difficult to really know if it was the battery at fault.

Not a new issue either - My MY16 Octavia had both the battery and alternator replaced in the first year under warranty. The replacement Moll EFB has lasted well since then.

7 hours ago, nta16 said:

@Micky 32 apollogises in all my rambling I forgot to put perhaps your battery is bunged up or had it and unable to take more charge but if so I'm a bit surprised your charger doesn't indicate this, by perhaps never showing full/100%.

I stuck it on the charger again for the craic. This time it took longer to “fully” charge the battery. One hour and 20 mins. Hooked up the obd 11 and it reports the state of charge is 87%!. It usually hovers on average 68-75% with every day driving. However the ah reserve capacity didn’t rise much. It was about 50ah the same reading as when it was at 70% state of charge. On the Topdon tester i got an extra 60 amps bringing it up to 591 amps out of 700 and reported “ good battery”

Interestingly Varta advises against using EFB batteries for brake energy recuperation cars. They should only be fitted to cars with basic start stop. They say that the spike of high voltage and forced high amps in recuperation mode can increase degradation prematurely. Doing logs myself i have seen 15.3v and about 30-40 amps forced into the battery when braking or slowing down. Sometimes i have seen normal constant charging at 15v. Mostly i see 14.5v but if my battery is pushing 40 degrees it drops to 14v constant charge.

I guess it’s VW and their bean counters.

Edited 19 May19 May by Micky 32

8 minutes ago, Micky 32 said:

It usually hovers on average 68-75% with every day driving.

That's a bit off my idea of fully charged and even away from VW's (about 80%(?)) and 87% isn't 100% (depending on what and how the meaures are).

TopDon, OBDEleven - what about putting multimeter probes directly on the battery terminals, after the car hasn't been used or charged for as many hours as possible, what's the voltage reading then?

My Ring charger and MartinDale multimeter give the same voltage reading within a knat's whisker I go by than to give me at least intitial idea of the battery, I can be pessermistic but I find the battery tester I 've used and hear about seem very pessermistic or set for battery sellers. The 12v battery must remain one of the most oversold and premature replacement car parts. Yes of course they need, or are best replaced, at some piont but not as soon as many are. Thank gawd I bought those shares in 12v battery producers.

Has you can got brake energy recuperation or more the alternator taking a break.

I note you take 30 minutes and one hour 20 minutes to charge your battery yet it took 15 hours to charge my wife's (AGM) battery and it wasn't what most would call ow in charge - what amps is your charger going at?

Yeah i have used the multimeter and a battery monitor and they all correspond with the bms reading on obd11. All vw’s seem to have brake recuperation. I think it’s more intense on the new cars. My old 2017 Passat with brake recuperation and a AGM battery never went over 14.5 volts unlike the 15-15.3v i see in my vRS.

I rarely ever see my SOC reach 80% on the bms. At most even after long drives i will see max 75% but it mostly hovers around 70% . If you go in and out of the car a few times ( unlocking and locking) when parked it doesn’t take much for it to drop down to 63-65%. The start stop doesn’t work when it drops to 60%. Also the brake recuperation doesn’t work under 70% the battery constantly charges..

A few observations. If you do get the battery to 80%+ ( according to the obd11) the alternator completely shuts off but you get the charging voltage when braking. Between 70-80% the alternator will trickle charge with voltages ranging from 12.7-13 volts but on braking the usual 14.6-15.3v . Below 70% the battery charges constantly 14.5-15v.

My charger is only a 6 amp, nothing special. It started off at 5 amps draw and over the hour/20 mins gradually dropped down to 1 amp before shutting off and saying “ full”.

Edited 19 May19 May by Micky 32

Two things I'd try. Get the battery to fully using a different lower amps charger2 or 3 if possible and allow for a much, much, much longer recharge time.

Disconnect, pull the fuse, always, always turn the stop/start off and see what differences these two thibgs make.

Just using simplistic maths, so if you battery has never been above 80%, at least after the VW computer program dragged it to there from new, then that's where it drops from, the 80% so a 10% drop takes it to 72% where as if it had a start at 90% or 100% the 10% drops would be 81% and 90%, more margin and less wear and loss.

The programing for the AGM ("Fleece" as our dear VW freinds call it, bless their cotton socks) is apparantly different to that for an EFB battery - though AGM batteries were fitted to "classic" cars at least in America many years back on car with "dumb" large heavy crude Americian alternators without issue and giving good service, they don't have as much special requirements as many make out or have been told.

Think of a battery like a current bank account some can budget the in and outs well whereas others can't and run deficients, or mains power electric use in homes, some have high bills others have lower bills, generally the more various appliances you have the more likily they are used or in-standby power sucking (perhaps with the lights on and curtains open in every room all nights to show how lucky the people living there are).

It's more "regeneration" from braking, not accelorating, well that's how it was at least. - SSP-426-Start-stop-system-2009.pdf

After that beautiful 87% charge today it eventually went back down 74% SOC ( according to obd 11) after a few trips. I then took a 40 mile round trip . 20 miles to my destination ( no stops). When i got there it had reached 77% soc. I was there for an hour. When i got back into the car for the return journey it had dropped to 73%. By the tiime i got home it only reached 75% soc.

There’s just no way normal driving will get my battery to 80%.

12 hours ago, nta16 said:

Two things I'd try. Get the battery to fully using a different lower amps charger2 or 3 if possible and allow for a much, much, much longer recharge time.

I often charge the VW EFB batteries on our Skodas with a 0.8 amp motorcycle CTEK, gets ‘em close to 100% but after a couple of running around they’re down to 60 - 70%……..?

4 minutes ago, Berisford said:

I often charge the VW EFB batteries on our Skodas with a 0.8 amp motorcycle CTEK, gets ‘em close to 100% but after a couple of running around they’re down to 60 - 70%……..?

AFAIK, this is normal behaviour for the smart alternator, you will probably see higher SOC with longer trips where regenerative charging has more opportunity to top-up the charge.

Sulphation is a normal, reversable process of the chemical reaction within lead acid cells, where small crystals of lead sulphate form on the cell electrodes (plates).

When the cell SOC remains significantly below 75% for prolonged periods, the lead sulphate crystals become larger (hard sulphate) and resistant to being dissolved during charging, this then makes that part of the cell inactive.

For a vehicle where shorter runs are common, occasional full recharges from an external smart charger will, in most cases, help extend the life of the battery by more fully dissolving the lead sulphate crystals before they grow to a size where they become insoluble.