Hi guys,
Did anybody require coding when fitting a new car battery on a 7.5R?
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Hi guys,
Did anybody require coding when fitting a new car battery on a 7.5R?
You dont have to, but you should let the car know a new battery has been fitted so that it can charge it accordingly. The new battery might be slightly higher (or lower) CCA's, and most factory batteries are EFB technology whereas replacement batteries are mostly the superior AGM technology.
So you dont have to and im sure there are thousands of modern cars running around with new batteries that have not been coded to the car, but for battery longevity, you should.
And while you are coding the battery, consider disabling the start/stop system as these are battery killers. The new battery will last several years longer if you disable the stop/start.
Also see here: Coding new battery?
Thanks mate 👍
@R snow: Hi.
hmm....... maybe a different perspective might be useful?
The 4 x adaptation channels that tell the hex19 module about your battery were put there by the car designers for a very good purpose. In the main, that purpose is to initialize (in part) the starting parameters for the car's Energy Management System (EMS) - which on the mk7 Golfs that are used in Australia is quite sophisticated.
Now, not ALL of these 4 x adaptation channels have the same value in the operation of the EMS, but they ALL have a purpose (VW is not in the habit of randomly adding to the channel database in a module)
For the purpose of your question - it's important to understand that the EMS in an Australian Golf (which is fitted with a battery monitor module that appears on the negative battery terminal - it's called "J367", see below) has both short-term and long-term functionality. Yes, modern EMSs (including the system used on MQB platform cars) are designed to optimize battery longevity and long-term battery performance. And, to do this - the EMS maintains a running history of every milli-amp that is extracted/injected from/to the battery. That's why it's necessary when using an external-charger, or when jump-starting a mk7 to use the car earth rather than direct connection to the battery negative terminal - because the recording device for battery current flow (J367) needs to be in-circuit.
So- the reason why you need to tell the hex19 module about the installation of a new battery is two-fold; to reset the car's history records for the old battery and to update the EMS with any changes about the new battery. Even if you are replacing like-with-like, the hex 19 module still needs updating (IMO)!!
Of course if these channels are not changed, the EMS will likely still satisfy the new battery's short term charging needs - but the EMS will assume that the old battery is still installed for the purpose of long-term battery functionality. This means that the EMS objective of maximizing battery longevity and long-term battery performance must be compromised!!!
Given that these are not cheap batteries - my hunch is that the extra effort needed to make the coding changes will likely deliver a financial return in the long-run and it will likely be better for this fragile blue planet (I reckon)!! Although I've no doubt that nay-sayers will claim that they have not observed any lessening of battery life when these changes are not made (how do they know?)!
So, bottom line = making the coding changes is good for you and more importantly (for me), it's good for us!!!!:banana:
Don
https://www.vwwatercooled.com.au/for...7YcCupng-1.jpg
Well said Don and I concur!!!
Another vote here for coding for optimum battery life.
Don, do you have an opinion on the charging strategy VAG have adopted for Golfs with Auto stop/start ?
I have certainly noticed some "interesting" battery voltage variations with the engine running, especially after I've had the battery on a charger to top it up. I suspect that deliberately not keeping the battery fully charged all the time may contribute to the shorter battery life many owners have experienced over recent years.
That is done so regenerative braking has some capacity available to useQuote:
Originally Posted by gregozedobe
Yes, as @Hillbilly correctly says - the apparent shortfall in the charging regime of the EMS on Australian MQB platform cars is deliberately designed to create a headroom in battery capacity for the injection of recuperation energy. Although I'm not sure for certain - I believe that this was the reason why VAG removed the SOC (State-Of-Charge) facility that appeared on early versions of the mk7 Golf.Quote:
Originally Posted by gregozedobe
The SOC measurement on these early cars never reported 100% (it almost always read 70%-80% which determined the size of remaining recuperation headroom capacity). I suspect that this resulted in lots of complaints to the mother-ship in Germany - which ultimately resulted in the removal of SOC readings on newer models - I think!!
Don
PS: I'd not considered the "topping-up" matter before - but I suspect that this is not necessary as a general practice. I don't think that it does any harm (the EMS will simply switch-off recuperation because the battery headroom capacity is full) - but I'm not convinced that it has a benefit -more than happy to be corrected!
PPS: I hope that when charging the battery - it is in-situ (i.e. with both of the car battery leads connected) and that you use the correct earthing protocol. As I have said, it's vital for the long-term objectives of the EMS that J367 is in-circuit for every milli-amp injected-into, or extracted-from the battery - see the wiring arrangement below.
https://www.vwwatercooled.com.au/for...HM8CJpng-1.jpg
Don, thanks for your reply.
I'm operating under the (possibly mistaken) belief that if a lead acid car battery is allowed to remain at a lower level of charge then this can increase sulfation on the plates, which leads to reduced long term charge capacity.
As I may not drive my Golf R for a week or so sometimes, and at other times I may only make short trips, as a result my battery may sometimes be at significantly less than 100% charge.
I have read many, many reports of modern Golf R batteries not lasting very well (often 3 years or less), but I want my battery to last a bit longer if I can.
I use a good quality charger (CTEK MXS 10 amp) every 2 - 4 weeks, connected to the special earth terminal on the firewall. I have had my Auto stop/start coded off (I hate it, and I rarely drive in traffic heavy enough to justify it's existence on my car).