Battery dying?

[Eaglehawk]

Eaglerhawk: I guess NRMA haven't caught-up with advances in newer generation control modules - particularly in cars with Start Stop!

Most important question is - does the new battery have a BEM sticker?
Don

No BEM sticker (at least at the top of the battery with the rest of the stickers). But thank you for your steps and wealth of knowledge. I will investigate and purchase something in the near future. I didn't realise that were "new kids on the block", time to research...

Thanks again. Add another thankful forum member.

[Jondalar]

So nobody can shed any light on the slow / long cranking time before the engine fires on my wife's 2014 2.0 TDI?

[Reedy]

The only long crank issue I had was when I got the timing chain replaced and they put it back together with the timing on the crank shaft out. The cams and crank shaft would do a full cycle before firing up, but this gave me an engine light.


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[Eaglehawk]

So, I bit the bullet and got myself the OBDeleven. Did some simple coding yesterday to make sure I knew what I was doing (instrument staging, traffic, sat nav nag...)

So, tonight I did the battery. As DV52 suggested, the serial number was still the default, the capacity was set to 68 and the battery technology was set to "Fleece". WTF?

I've set the capacity to 70Ah (written on new battery), changed the serial number, and changed the battery technology to EFB. Have I done the right thing?

[DV52]

So, I bit the bullet and got myself the OBDeleven. Did some simple coding yesterday to make sure I knew what I was doing (instrument staging, traffic, sat nav nag...)

So, tonight I did the battery. As DV52 suggested, the serial number was still the default, the capacity was set to 68 and the battery technology was set to "Fleece". WTF?

I've set the capacity to 70Ah (written on new battery), changed the serial number, and changed the battery technology to EFB. Have I done the right thing?

Eaglehawk: New OBD11 dongle -what are your observations? I like certain features, don't like others. It's simple to use, but it's very slow - even with a good internet connection.

As for the changes, if the new settings more accurately reflect the characteristics of the new battery, then the changes have to be better! You certainly haven't done the wrong thing IMO!

Don

PS: the "Fleece" setting" simply refers to the weave of the glass mat in an AGM battery - I think

[Eaglehawk]

Eaglehawk: New OBD11 dongle -what are your observations? I like certain features, don't like others. It's simple to use, but it's very slow - even with a good internet connection.

As for the changes, if the new settings more accurately reflect the characteristics of the new battery, then the changes have to be better! You certainly haven't done the wrong thing IMO!

Don

PS: the "Fleece" setting" simply refers to the weave of the glass mat in an AGM battery - I think

Ah, I'll change it back to Fleece then. There was a Binary-AGM setting as well.

The dongle: Yes, I loved the features, but it still does feel "overwhelming" to a new user (I'd hate to think what VCDS would be like). The best feature I think was the "Apps" functions to show you the common settings that are available for your model car. The bluetooth seems to disconnect "at some point" when you first start using it. Not sure if it's a dongle issue or the car dropping voltage temporarily.

[Jondalar]

OK so finally today the battery failed to crank the wife's Golf over and it was replaced under warranty. This was by VW roadside assist, not RACQ. I was texting her saying make sure he tells the car about the new battery, but he had told her that the car would work that out all by itself. There were 4 errors which gradually cleared over her drive to work. Thoughts?

[DV52]

OK so finally today the battery failed to crank the wife's Golf over and it was replaced under warranty. This was by VW roadside assist, not RACQ. I was texting her saying make sure he tells the car about the new battery, but he had told her that the car would work that out all by itself. There were 4 errors which gradually cleared over her drive to work. Thoughts?

Jondalar: hi. I'm just a rank amateur compared to the experienced folk at VW road-assist, but I do like to make sure that any statement from any VW-Australia agent is at least logical (because sadly, many aren't)! So, here's my problem - notwithstanding that a mk7 is a fairly intelligent vehicle, how does it automatically know that the battery is changed?

Yes, the control modules can see that the voltage has been re-established (after disappearing for a few minutes), but how does the car distinguish between other events that cause this symptom (i.e. battery voltage collapse from a weak battery and battery lead remove and re-connection) and the less frequent act of an actual battery replacement? AGM batteries are also fairly smart devices, but they don't talk to control modules in a way that discloses their identity - they are just batteries!

I'd like to give the road-assist person the benefit of the doubt and suggest that he/she was probably referring to the error reports that were generated in the removal/replacement exercise and that have subsequently cleared. But it's folly to believe that the car has a similar IQ to that of the road-assist guy and could therefore know that the battery was replaced - without any changes to the CAN Gateway module settings (IMO). If this were the case then there would be no need for Ross-Tech to create their video on battery replacement and there would no need for VW to make the three adaptation channel settings available for consumer use (IMO)

Don

[willsy01]

Hmmm, I replaced the battery in my Mk6 R myself......OEM battery replaced with another Varta battery. I haven't changed anything in the computer though.....

[DV52]

Hmmm, I replaced the battery in my Mk6 R myself......OEM battery replaced with another Varta battery. I haven't changed anything in the computer though.....

Will: hello and thank you for the comment - though I'm not sure quite how to respond! So I'll just say (politely and with due respect- I hope) that whilst the mk6 and mk7 share a common name for marketing purposes, there is a world of difference in the DNA of their respective control modules.

One of the numerous changes that was made to the car when the Golf was transformed to the MQB platform was a rearrangement of nearly all of the CAN buses and the introduction of entirely new (to the Golf series) facilities (like Leuchte programming). The inclusion of the battery monitor control module (J367) on the LIN data bus to the CAN Gateway (J533) and the inclusion of the 3 x battery adaptation channels that I identified earlier (which I understand were already present on some Audi models) was part of these changes.

But as I have said previously, the car won't blow-up if the channel settings aren't altered - what will simply happen is that the car's "internal" understanding of the battery capabilities will rely on the information that has been built-up over the life of the old obsolete battery. In time and if the control modules aren't required to make critical decisions based on the calculated "System Voltage" in the interim, I guess that the obsolete historic values will be eventually written-over by the battery's true data. But it's not an ideal situation IMO if you have paid good money for a new battery. Nevertheless, I fully acknowledge that ignoring this procedure will be an acceptable alternative to some. As the cliche says "it's a free world" - I really don't mind if others are prepared to adopt the Laissez-faire approach!

Don

[Jondalar]

J
Yes, the control modules can see that the voltage has been re-established (after disappearing for a few minutes), but how does the car distinguish between other events that cause this symptom (i.e. battery voltage collapse from a weak battery and battery lead remove and re-connection) and the less frequent act of an actual battery replacement? AGM batteries are also fairly smart devices, but they don't talk to control modules in a way that discloses their identity - they are just batteries!

I'd like to give the road-assist person the benefit of the doubt and suggest that he/she was probably referring to the error reports that were generated in the removal/replacement exercise and that have subsequently cleared. But it's folly to believe that the car has a similar IQ to that of the road-assist guy and could therefore know that the battery was replaced - without any changes to the CAN Gateway module settings (IMO). If this were the case then there would be no need for Ross-Tech to create their video on battery replacement and there would no need for VW to make the three adaptation channel settings available for consumer use (IMO)

Don

Thanks for the reply, I do have an OBD Eleven module so I'll have a play with that next time I get a chance. It's a bit sad than an actual VW roadside assist person wouldn't know about the battery system properly though.

Cheers,
Karl

[BlitzAce]

Not sure I remember where I read these - but I recall some one saying if the new battery isn't adapted to the car, simply speaking the car would think it's the same old one, and overcharges it over time to compensate for the.. not sure how to put it - because all batteries gradually lose their charge capacity over the years? And it will simply kill the new battery in time, as well.

Although I've also read oh how the battery module is adapted from Audi, and in Audis they simply learn the new settings over time, with no ill-effects..?

However in my own experience, I know at least 3 people that had their batteries changed by our local dealer - and the replacements died in less time than the original ones. Out of curiosity I plugged in their cars to my VCDS and found out all of them have the default settings which came with the car (the battery serial number is the same, IINM it was 00000 or something), thus strengthening my first point above. Although, I asked our dealer and they too, said, no settings are necessary - the car will self learn (with the cynical 'what does he know' look from the staff.. albeit I bet I've owned far more VWs than the dude).

Comments, anyone?

[DV52]

Not sure I remember where I read these - but I recall some one saying if the new battery isn't adapted to the car, simply speaking the car would think it's the same old one, and overcharges it over time to compensate for the.. not sure how to put it - because all batteries gradually lose their charge capacity over the years? And it will simply kill the new battery in time, as well.

Although I've also read oh how the battery module is adapted from Audi, and in Audis they simply learn the new settings over time, with no ill-effects..?

However in my own experience, I know at least 3 people that had their batteries changed by our local dealer - and the replacements died in less time than the original ones. Out of curiosity I plugged in their cars to my VCDS and found out all of them have the default settings which came with the car (the battery serial number is the same, IINM it was 00000 or something), thus strengthening my first point above. Although, I asked our dealer and they too, said, no settings are necessary - the car will self learn (with the cynical 'what does he know' look from the staff.. albeit I bet I've owned far more VWs than the dude).

Comments, anyone?

Blitz Ace: Hello. My position is that the good Burghers at VW have themselves to blame! If their general approach to all their cars' technology wasn't so shrouded in secrecy, them perhaps all of us (me included) might be writing actual facts, rather than speculation!

I'm guessing, but I'm not sure that your observations regarding the longevity of the replacement batteries for the "3 people" necessarily resulted because of a failure to alter the 3 x adaptation channel settings in the CAN gateway. In my experience, there are some absolutely crap batteries out there which dealers/retailers will happily sell as exact replacements but which are no-where as good as the batteries in new vehicles - because car manufacturers have much better purchasing power and because they are able to scrutinize their stock much more professionally!

Perhaps the mk7 is intelligent enough to modulate the charging characteristics of a battery taking into account its age and its capacity depletion curve over time- I'm not sure (but I wouldn't have thought so - I would have thought that such matters would have been more determined by the fundamental laws of physics such as the degradation in the internal impedance of the battery, itself) My own personal conclusion after reading VW's material is that the opposite is true. That is, the greater the period from battery replacement, the less it matters that the CAN Gateway was not informed of the change - because the historic battery table is gradually overwritten with the performance of the new battery. But I'm more than happy to be proven wrong!!

Don

[BlitzAce]

Well.. yea? Nothing conclusive at this point I guess. Although I've taken it to replace the stock EFB with a slightly higher capacity Varta Silver E39 AGM, even though I'm still under warranty for the battery. Even bought a C-Tek Start/Stop charger for periodical maintenance (at least that's the idea..). And I recall another point - the 3 owners who already had their batteries replaced by the local dealer didn't notice any low battery warning before their battery died again, visually or audio like previously, while on the stock battery the car came with. I would say it's because the battery module can't really tell the battery is low since it wasn't coded properly during the change..? I don't know.

I'm still appalled that most of the people I know had their cars dying on them, the batteries I mean, in less than 2 years. Pretty much almost all of my mk7 friends had their batteries changed, by now. I'm on my 2nd replacement battery myself, and I got the car in July or so, 2014. I would say it's the hot weather and all the Start/Stop, ambient lights and everything the mk7 has, but honestly, a proper explanation would be good. Been lurking around for quite a while, and if a resident expert such as you has doubts than I guess the search for answers is still ongoing, I suppose. Not on the quest on proving who's right or wrong here, just needing answers for the good of us 7 owners

[mattchuu]

Is there any wisdom on using a ctek mxs 5 charger on a golf 7 gti?

I use it every couple of months on an older mk5, but i always disconnect the battery and charge it.

I'm punishing my battery with SS and a dashcam, so i'd like to periodically top it up for 24h to get it back to full charge.

If i recondition the battery, should i disconnect it from the car? it does put 16v through, so i doubt that would be good for the car?

Matt