Is the 12v battery covered under VWs 3 year warranty?

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SRGTD
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by SRGTD »

silverhairs wrote: Fri Nov 05, 2021 12:54 pm Getting back to the question about VW 3 year warranty, my mate with a VW, they said "the battery isn't covered, it's a one year warranty", he had to pay.
VW new car warranty terms and conditions at the link below;

https://www.volkswagen.co.uk/en/owners- ... terms.html

There is no exclusion of the car’s battery (other than key fob and alarm batteries), and there are owners on golfgtiforum.co.uk and vwroc.com who’ve had their batteries replaced under warranty.
Johntheo1
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

Wouldn't be too worried about the key fob batteries, scrapped a VW Bora after exactly 19 years with the original key fob batteries and one replacement 12V.
SRGTD
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by SRGTD »

Johntheo1 wrote: Fri Nov 05, 2021 2:46 pm Wouldn't be too worried about the key fob batteries, scrapped a VW Bora after exactly 19 years with the original key fob batteries and one replacement 12V.
Agree; the key fob batteries do hold up well on cars without keyless entry. That doesn’t seem to be the case on cars with keyless entry though - based on the experience of owners with keyless entry on other forums, quite a few instances of the fob batteries ‘dying’ at 12 months old, and many seem to need replacing every 12-18 months.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by RUM4MO »

Johntheo1 wrote: Fri Nov 05, 2021 2:46 pm Wouldn't be too worried about the key fob batteries, scrapped a VW Bora after exactly 19 years with the original key fob batteries and one replacement 12V.
BTW, I am quite happy that presently my wife's 2015 Polo is not over charging its battery now since I changed the serial number, presently it is keeping it charged higher than intended so there must be a slight waste of fuel happening, I'm probably more interested in where this is leading to as initially the changing charging profile/level came as a step change and was at the start of that change definitely over charging that battery, so logically the charging system should eventually adapt itself back to these values that caused it to constantly charge at 14.9V.

Key fob batteries, yes, I replaced the batteries in the keys of my bought new 2000 Passat 4Motion at maybe 12 years - why, because these batteries would now be beyond their useful age, same for my wife's bought new 2002 Polo.
With my 2011 Audi S4, I changed the key batteries just before the 10 year point, the open circuit voltage of the old ones, even the mainly unused one was down to just over 3V, I did the same on the 2015 Polo at the 6 year point, and again the batteries were both getting close to or below 3V.
My daughter's May 2019 SEAT Leon Cupra reported "replace key battery" or a similar warning back in the summer time, and its battery in her key was down to just below 3V - replacing the Panasonic original with a Sony(bought in error by me) sorted out that warning - her partner's key has not caused any warnings to get issued yet, though he rarely drives that car - it does not have KESSY, so goodness knows why newer VW Group cars need key batteries replaced sooner than older ones did.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by RUM4MO »

silverhairs wrote: Fri Nov 05, 2021 12:54 pm Looking at all your posts, and all the facts and figures. I've been driving for 64 years and always kept an eye on the fluid level of the batteries where needed, but I've never worried about the output or the condition of the battery, as long as the car started, everything was OK. Sometimes ignorance is bliss.
In all my years I've had just 2 battery faults, once with a 3Ltr Ford Granada, been away for the weekend come to start it on the Monday and nothing, jump started it with another battery, took it down to a battery specialist, the shorted it out and one cell started to smoke, another time with my Nissan Note, started first thing, went shopping, got back in the car, nothing. Called out recovery, they jump started it, tested the battery, DEAD !! New battery.
Am I worried about the battery in the Polo, certainly not.

snip ------snip
Yes I agree that you should never need to "keep a close eye" on your battery, though it seems that much cheapness coupled with regenerative charging and some poor choices of battery suppliers by VW Group has changed things a bit for many persons.
My car battery history started with needing to either replace the Ford battery or the starter to keep going reliably in winter, new battery was usually cheapest option. That was followed by a 1991 VX Cav GSI 4X4 that had a factory fitted alarm that needed a battery to remain in tip top condition, or it would set the alarm off, so cheapest option seemed to be a new battery every 4 years after it had started setting its alarm off again. My wife had that battery "okay", stopped when returning home, returned to a battery "dead", so RAC jump started it and I bought a new battery, mind you, I think it issued an early warning when I used it the day before - but I did nothing! My 2000 VW Passat 4Motion only needed a new battery as I had to over use it to prime the fuel system after replacing the filter, only to find the fuel was primed but the oil had been washed out of the rings so compression was too low, a known issue with that engine and many Jaguar and other V engines, you live and learn it seems. My older daughter's 2009 SEAT Ibiza 1.4 SC had a horrible BCM S/W issue that exposed the fact that its battery was aging, without that fault that battery would have lasted that car with us.

Edit:- I'd expect most people with a modern car will get an early warning of battery degradation by the auto Stop/Start stopping being enabled at its usual point in the journey.
Johntheo1
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

Re Overcharging, As I think I stated previously, all my other VWs, for years, charged at a constant 14.2/14.4V and all lasted for ever, I knew a few "commercial travelers" that used to drive long distances every day and would clock up well over 1,000 miles/week, never heard of their batteries suffering any overcharging effects from charging for hours on end at 14.3V or so. Also some makes, like Mercedes? had a ambient temperature bias on the charging voltage and could charge at up to and maybe a touch over 15V., so in winter these batteries could be charged for hours on end at 15V in very low ambient temperatures. So, I wonder, how many batteries are actually overcharged by alternators (assuming no regulator fault). Maybe more likely now with the advent of our BMS systems?.
Harrihealey02
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Harrihealey02 »

Just to let everyone know, the 12v battery is covered under the 3 year VW manufacture warranty, they were going to replace mine but I decided to pay myself as the car would have been seen in 1 week and stay with them for 2 days which I couldn’t wait for as it couldn’t start.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Harrihealey02 »

I went to Halfords instead same day.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by RUM4MO »

Harrihealey02 wrote: Sat Nov 06, 2021 8:56 pm I went to Halfords instead same day.
I can easily understand that, getting this sorted out FOC but being without a car for a period of time is not good, VW Group win again, but so do you - sort of.

I've always been very reluctant to let any dealership sort out my cars, while I've needed to work around that.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by heftyshooly »

So, after dinner research, it turns out AGM batteries, unlike standard lead acid need to be charged at higher voltages ~14.8V, instead of the usual 14.4V. This can be confirmed in this official Varta document for example http://d26maze4pb6to3.cloudfront.net/va ... ure_UK.pdf (page 20).

So by constantly charging at 14.9, my guess is that the BCM is probably trying to determine the 100% state of charge, before switching to the more efficient intermittent charge. It should not degrade the battery.

Here is a more technical document on AGM batteries
https://www.google.com/url?sa=t&source= ... ocC-SaPAm3
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

Depending on which AGM you buy, some can give 800 cycles @50% DOD & some 400 @50% DOD, I didn't actually come across a number for the EFB type but did see a mention of 200 cycles @50% DOD for a "conventional" type so assuming the EFB falls under this category then my battery should give,200*50%*59, 5900 AH but VAG are only allowing a equivalent 100 cycles @ 50% DOD, which seems very conservative as one would think that the normal DOD would be in the region 10% to 25%. I wonder do VAG allow for the enhanced cycle time when a AGM battery is installed.

This is from one of the links above... "Exceptionally long lasting: up to eight times the cyclic stability of conventional batteries (up to 800 cycles @50% DOD)" (Refers to AGM deep cycle type)
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

I see when/if installing a new AGM battery that there are two settings, either AGM Binary or Fleece. From what I read it as recommended that the Fleece option is chosen.
I also noticed on my Polo after start up that the voltage goes to 15V and the charging amps to 26 for a minute or so before reducing to 13.4V ish, the engine RPM are also increased during this period of a minute or two, probably another reason to get the settings correct on battery change out.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

Another set of battery readings from a Jan 2019 Polo, 14,354 kms. All very short runs. I missed 1838 but that was the battery voltage temperature, normally close to the 1837 value. Battery at rest voltage is 12.5V which should be ~ 47AH, (59*80%) but usable battery voltage shows 28AH. The acid test will be in the next fortnight as the car will be parked up for 14 days from tomorrow. Watch this space as none of my VWs in 59 years of driving has ever failed to start.

I trickle charged (3.8A smart charger) the battery for 1 hour, this is reflected in the usable battery charge increasing by 3AH so "proves" that the battery is being fully charged even with very short runs but begs the question that IF the usable battery charge is actually 29/30AH, does this mean that all batteries SOC fall to this level in 3 years?, and how are (my) VW battery lives of up to 12 years explained.

14:58:57 24/1/2022
IDE01834 Battery voltage 12.166 V
IDE01836 Battery current -4.386 A
IDE01837 Temperature of battery sensor 12 °C
IDE01839 Battery charge level 79 %
IDE01841 Battery internal resistance 7.8 mOhm
IDE01842 Usable battery charge 28 Ah
IDE01843 Battery voltage at rest 12.5 V
IDE01848 Energy balance of last driving cycle 0.0 Ah
IDE01849 Previous journey duration 0.0 H
IDE07681-MAS06086 Battery total charging throughput-Total re-charge 1354.8 Ah
IDE07681-MAS06087 Battery total charging throughput-Entire energy throughput 1478.3 Ah

19:25:42 24/1/2022 after 1 hour charge.
IDE01836 Battery current -5.689 A
IDE01837 Temperature of battery sensor 16 °C
IDE01838 Battery temperature 16 °C
IDE01839 Battery charge level 82 %
IDE01841 Battery internal resistance 7.6 mOhm
IDE01842 Usable battery charge 30 Ah
IDE01843 Battery voltage at rest 12.5 V
Johntheo1
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by Johntheo1 »

Car started after 14 days idle, drove < 0.5 miles with head lights + HRS + fan on speed 2, stop/start operated perfectly.
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Re: Is the 12v battery covered under VWs 3 year warranty?

Post by johntheo2 »

Had to change my name to Johntheo2 (couldn't log on with Johntheo1 even after password reset).

Here is latest set of battery readings, SOC down a little as I had been pumping up a expansion vessel for a neighbour with battery powered mini air compressor just before taking readings.

Jan 2019 Polo AW1
11:06:18 08/05/2022 15,175 kms
IDE01834 Battery voltage 12.220 V
IDE01836 Battery current -5.107 A
IDE01837 Temperature of battery sensor 24 °C
IDE01839 Battery charge level 71 %
IDE01841 Battery internal resistance 6.6 mOhm
IDE01842 Usable battery charge 27 Ah
IDE01843 Battery voltage at rest 12.4 V
IDE01948 Battery internal resistance not normed 6.6 mOhm
IDE07681-MAS06086 Battery total charging throughput-Total re-charge 1494.7 Ah
IDE07681-MAS06087 Battery total charging throughput-Entire energy throughput 1627.3 Ah
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