Battery dying?

[h100vw]

Are you saying not to carry out recon by the ctek charger?

^ ^^^ hm........ there's a couple of things that are worth noting about batteries on mk7 vehicles -they are not like the batteries that were used in cars in "the old-days" - alas:

First , the veracity of the SOC measurement is entirely dependent on how well the car owner has respected the battery monitor control module (J367). It sits just next-to the negative battery terminal and its job is to translate the flow of electrical current to/from the battery to the car's analogue-to-digital converters. The destination of the data stream from J367 is initially the CAN Gateway (address hex09) and eventually the data is used to calculate what VW calls "System Voltage" (which is very different to Battery Voltage). Most (all?) of the decisions that the various control modules in a mk7 make about the car's rail-voltage is based on the calculated "System Voltage", not battery voltage, so it's important to ensure that this calculation is done correctly FOR THE ENTIRE LIFE OF THE BATTERY!

Stuff like charging the battery by directly placing the negative charger lead on the negative battery terminal is a definite no-no as this practice by-passes J367. The result is that the digital table about the car's SOC is incorrect! Another no-no is failing to tell the CAN Gateway (and J367) that the old battery has been replaced. This causes the calculation of System Voltage to use the obsolete history file from the discarded battery!

So, if you do change the battery, make sure that you follow the correct procedure for recording the new battery specifications in the control module tables (there are 3 x adaptation channels that need to be updated). If you don't buy a BEM replacement battery, at the very least you should change the serial number of the battery in the CAN gateway (which is UDS type for a mk7).

Finally, the other aspect of a mk7 battery that is worth noting (IMO) is the types of OEM battery that VW uses, which are enhanced flooded battery (EFB battery) and absorbent glass mat battery (AGM battery). Both of these types are superior to conventional batteries and AGM is superior to EFB. These batteries are matched to the needs of the car's features - such as Start Stop. Sure you could try a cheaper conventional battery, but in the long term, the economics likely would be questionable -IMO.

Don

[DV52]

Are you saying not to carry out recon by the ctek charger?

h100vw: I can't comment, I have no experience with this charger - I assume that the ctek charger is compatible with AGM/EFB batteries and that the "reconditioning" feature works for those batteries that have a sulphation issue.

Desulphation processes normally raise the rail voltage to close to 16 Volts. Not sure what this does to the control modules if the desulphation process is part of the normal charging regime and the battery is left connected to the car - I just don't know.

If the battery is removed from the car for the reconditioning process, make sure that the CAN Gateway is told about the reconditioned battery!

Don

[h100vw]

I have used it on a battery outside a car and on one still fitted and connected.

It was an 8L S3 not anything new school, I drove it at the weekend several times. Your point is valid on the voltage, the instructions don't make comment on disconnecting the battery from the car to carry out the process.

They are compatible with all batteries from what I read in the instructions.

[guile]

very interesting info, i replaced my battery on a 2010 S3 for the 2nd time in less than 3 years (car doesn't get much use) and i also bought a ctek trickle charger at the same time in an effort to stop me chewing tough batteries...

need to do a bit more home work to confirm if i need to update the CAN Gateway, any info is gratefully received...

[DV52]

very interesting info, i replaced my battery on a 2010 S3 for the 2nd time in less than 3 years (car doesn't get much use) and i also bought a ctek trickle charger at the same time in an effort to stop me chewing tough batteries...

need to do a bit more home work to confirm if i need to update the CAN Gateway, any info is gratefully received...

guile: Unfortunately, you will need a diagnostic cable like VCDS, or VCP (or even possibly, OBDeleven) to confirm the CAN Gateway requirement. Since your car is 2010, I suspect that the protocols in your CAN module won't be UDS, so the first part of the video below will be pertinent for your vehicle.

For anyone with a mk7, or an MQB platform vehicle (which will have a UDS based CAN Gateway) see the section ~4:45 minutes into the video

Don

[h100vw]

He has a VCDS lead so good there.

You seem well read on this subject Don. Not really for my benefit all my dubs are Flintstone but what do you do if you don't buy a battery from VW/AUDI?

Gavin

[DV52]

He has a VCDS lead so good there.

You seem well read on this subject Don. Not really for my benefit all my dubs are Flintstone but what do you do if you don't buy a battery from VW/AUDI?

Gavin

Gavin: Many thanks for the kind words, but the fact is that I'm a rank amateur compared to many folk on this forum whose expertise is just plain awesome!

As to your question, I would definitely NOT buy a battery from VW/Audi (rip-off merchants)!. Lot's of telephone calls to other battery retailers - but make sure that it's a BEM type (IMO)

Don

[Eaglehawk]

Great, so NRMA changed my battery without doing any coding changes. Time to find someone in the ACT that knows how to re-code it, or finally buy that VCDs cable I've wanted for years...

[DV52]

Great, so NRMA changed my battery without doing any coding changes. Time to find someone in the ACT that knows how to re-code it, or finally buy that VCDs cable I've wanted for years...

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? If so, then the task of introducing the identity of the new battery to the CAN Gateway is straight-forward. If the sticker isn't there, just decrease the setting in the adaptation channel IDE03256-MAS06108-Battery adaptation-Battery Serial Number by one (your default setting likely will be 1111111111). This should reset the history table in the car that has been previously been built-up from the now obsolete battery.
Also, if NRMA didn't replace the old battery with an EFB/AGM battery, then you might think about changing the setting on the adaptation channel IDE03256-MAS06106-Battery adaptation-Battery technology from the default setting EFB, to wet, or perhaps GEL

As for buying a diagnostic cable - carp diem! However, as I'm sure that you are aware, there is a "new kid on the block". Whilst I firmly believe that Uwe Ross's cable is by far the best in the industry (IMHO) - particularly the HEX NET, it ain't cheap. If you are not going to be a big user, consider the advantages of OBDeleven - especially the price! If you have a good internet connection at the place-of-use, OBD11 is a good entry option. You will need an Android tablet/phone, but even with this expense, it's much cheaper than the industry standard cable!

Don

[guile]

Since your car is 2010, I suspect that the protocols in your CAN module won't be UDS, so the first part of the video below will be pertinent for your vehicle.

awesome, thanks a lot for your help mate. i'll give it a crack at the weekend...