It Doesn’t Get Much Sadder
- Thread starter JSJQ
- Start date
-
- Tags
- alternator
That's a first . . . . Faulty alternator!
Not seen that fault pop up.
What's the van spec/engine.?
Not seen that fault pop up.
What's the van spec/engine.?
Thanks for your replies. I think we’ll never know what the problem was unless it happens again. The VW dealer said that all that was needed after the battery was replaced was for the battery to be coded. Once this was done the new battery operated within specs. So it seems it was not the alternator. I know little (if anything!) about electronics but the suggestion regarding the module sounds likely.
The van is a 2019 T6 transporter, tdi1400. Now home and in the garage.
Regards and keep safe. Our many friends including forum members are in our thoughts.
The van is a 2019 T6 transporter, tdi1400. Now home and in the garage.
Regards and keep safe. Our many friends including forum members are in our thoughts.
So this is implying that you can not simply change the starter battery when it fails!
Is this correct? News to me. Anyone got any information on this?
Loads on here.So this is implying that you can not simply change the starter battery when it fails!
Is this correct? News to me. Anyone got any information on this?
New battery needs coding..
I'll dig out a link later
Thanks. 
I did quickly look at this thread but assumed it only applied to capacity changes. Upgrading Starter Battery
What happens if you change like for like? Or just Bosch instead of Varta but same Ah?
Cheers.
I did quickly look at this thread but assumed it only applied to capacity changes. Upgrading Starter BatteryWhat happens if you change like for like? Or just Bosch instead of Varta but same Ah?
Cheers.
It should still get coded, you can swap out the battery and the van will still work but messes with the stop start system etc
If you remove a fully charged battery or a 50% charged batt for example and replace it with a battery with a different state of charge the van will not be able to tell and could get upset
If you remove a fully charged battery or a 50% charged batt for example and replace it with a battery with a different state of charge the van will not be able to tell and could get upset
P
Phil_G
Guest
I've heard this mentioned several times on here and whilst I accept it is the case, I dont actually follow why it is, not arguing just trying to understand... I can see how capacity monitoring is a Good Thing but you'd expect any charging regime to be determined by the battery voltage, not by capacity in vs out. Without draining the battery completely in a capacity test the ECU cant know what the capacity is cos big or small, van batteries are the same voltage, and manufacturers claimed capacities are hugely exaggerated (wasnt the law changed to improve this?) . I realise that measured capacity 'in' is often used as a safety charge-terminator for NiMh, NiCd and non-float CC chemistries, but a sensible CV duration wont overcharge a lead-acid, it cant be about the accuracy of the 80% SOC as it doesnt ever know the actual battery capacity, all it has to go on is the manufacturers 'claimed' capacity when its coded in - which could be wildly out. I can only think its to do with limiting the regen braking based on capacity - ie only allow the brakes to put back whats been measured to have been taken out, since this is a brief, high voltage, high current charge which could be detrimental if allowed on a 'full' battery. I dunno.
Obviously it works, cos thats how it is, but I would love to understand how - none of the explanations I've read make technical sense to me (as an electronics designer) (apparently a pretty thick electronics designer)
Cheers
Phil
Obviously it works, cos thats how it is, but I would love to understand how - none of the explanations I've read make technical sense to me
(as an electronics designer) (apparently a pretty thick electronics designer) Cheers
Phil
Last edited by a moderator:
You have echoed my own thoughts. I would also expect any intelligent system to self learn from the battery voltage and charge/discharge characteristics. It must already be able to compensate as a battery ages and loses capacity? Why cant it relearn if a new battery is installed? And, as you have stated, no two batteries are identical.
I've heard this mentioned several times on here and whilst I accept it is the case, I dont actually follow why it is, not arguing just trying to understand... I can see how capacity monitoring is a Good Thing but you'd expect any charging regime to be determined by the battery voltage, not by capacity in vs out. Without draining the battery completely in a capacity test the ECU cant know what the capacity is cos big or small, van batteries are the same voltage, and manufacturers claimed capacities are hugely exaggerated (wasnt the law changed to improve this?) . I realise that measured capacity 'in' is often used as a safety charge-terminator for NiMh, NiCd and non-float CC chemistries, but a sensible CV duration wont overcharge a lead-acid, it cant be about the accuracy of the 80% SOC as it doesnt ever know the actual battery capacity, all it has to go on is the manufacturers 'claimed' capacity when its coded in - which could be wildly out. I can only think its to do with limiting the regen braking based on capacity - ie only allow the brakes to put back whats been measured to have been taken out, since this is a brief, high voltage, high current charge which could be detrimental if allowed on a 'full' battery. I dunno.
Obviously it works, cos thats how it is, but I would love to understand how - none of the explanations I've read make technical sense to me
Cheers
Phil
I've been saying the same thing..(and also work in electronics!). with all the 'smart stuff' going on surely it would be pretty easy for the ECU to ascertain the batteries SOC/SOH and dynamically adjust its charging accordingly.
Interesting VWA come out in a 'lockdown' to change the battery on the drive tho!...mine has failed to start twice now over the past few weeks (as im using it less than usual)..I've just been limping it along until the dealer opens again.
P
Phil_G
Guest
I would love to understand this Pauly, you'd think that handling batteries in different stages of charge is the most fundamental requirement of any charger!
Surely it estimates the SOC from the at-rest battery voltage and regulates the alternator accordingly? If its low, do a bulk charge up to float then allow it to discharge
to the 80% voltage whilst measuring the A/H capacity of the 20%. Then allow up to that measured amount of regen braking. Sorry I feel I'm being argumentative but really dont mean to be...
I wonder if theres an actual VW technical document that explains?
Last edited by a moderator:
This was the quote from the previous post . . .
"Battery coding is important for EU6 engines with stop/start because the system monitors the battery state for capacity, SOH, SOC, etc...
Not needed on a Eu5 non-stop/start.
Although I have noticed that the system (Eu6) goes info what I think is a self learning state for around 10 start cycles after the battery has been disconnected........ I noticed odd stop/start and charging behaviours." - Upgrading Starter Battery
Here are the links for the SSP`s for more info:
https://www.t6forum.com/threads/vw-vag-ssp-self-study-programs.11179/
SSP 426 - Start/Stop System 2009
Here is a few clips from the 2019 Service Manual:
...
...
.
.
..........
So the official VW word is that the module needs coding, as @Pauly said above, to enter the new battery metrics and clear the old logs.
its assumed that the new battery would be be 100% SOC/SOH as its new,
but i think the observed "self learning state for around 10 start cycles after the battery has been disconnected" is the way that the Energy management system ensures that the battery is 100% SOC before thew stop/start kicks in and the battery monitor resets it self.
...................
fitting a new battery without coding may cause the EMS (energy management system) to assume that the battery still has a low SOH and poor ability to hold a charge and may adapt the battery charging strategy. This may intern end up effecting the new battery as it me not be charged up properly......
Now a lot of this is assumption as the EMS is software/firmware in the ECM, and we have no way of knowing how VW have coded the software and what flags or map parameters are being used.
You can use VCDS or a Pro Scanner to check the data PID`s for the EMS of which there are MANY !. ( i had some screen shots of them , but cant fiond them =[ )
................
"Battery coding is important for EU6 engines with stop/start because the system monitors the battery state for capacity, SOH, SOC, etc...
Not needed on a Eu5 non-stop/start.
Although I have noticed that the system (Eu6) goes info what I think is a self learning state for around 10 start cycles after the battery has been disconnected........ I noticed odd stop/start and charging behaviours." - Upgrading Starter Battery
Here are the links for the SSP`s for more info:
https://www.t6forum.com/threads/vw-vag-ssp-self-study-programs.11179/
SSP 426 - Start/Stop System 2009
Here is a few clips from the 2019 Service Manual:
...
...
.
.
..........
So the official VW word is that the module needs coding, as @Pauly said above, to enter the new battery metrics and clear the old logs.
its assumed that the new battery would be be 100% SOC/SOH as its new,
but i think the observed "self learning state for around 10 start cycles after the battery has been disconnected" is the way that the Energy management system ensures that the battery is 100% SOC before thew stop/start kicks in and the battery monitor resets it self.
...................
fitting a new battery without coding may cause the EMS (energy management system) to assume that the battery still has a low SOH and poor ability to hold a charge and may adapt the battery charging strategy. This may intern end up effecting the new battery as it me not be charged up properly......
Now a lot of this is assumption as the EMS is software/firmware in the ECM, and we have no way of knowing how VW have coded the software and what flags or map parameters are being used.
You can use VCDS or a Pro Scanner to check the data PID`s for the EMS of which there are MANY !. ( i had some screen shots of them , but cant fiond them =[ )
................
P
Phil_G
Guest
Ta v much Dell I'll have a read...
Very interesting. Changed my starter battery last year, have done no recoding (I’m guessing it’s a Vcds rather than Carista). Haven’t noticed any issues but expect I’ll need to get it hooked up next time we are allowed to meet up and someone brings their vcds.
Thanks for the info as always @Dellmassive Will have a look too.
What intrigues me is the VWA comment and it had to be transported (no pun intended) off:
This implies the new fitted battery was not charging? Not charging at all? Are there situations where the battery monitor control unit will shut down the whole charging system due to not being re-coded? I would of thought this is very unlikely especially if it goes into a learn cycle when a battery is reconnected. The plot thickens......
What intrigues me is the VWA comment and it had to be transported (no pun intended) off:
This implies the new fitted battery was not charging? Not charging at all? Are there situations where the battery monitor control unit will shut down the whole charging system due to not being re-coded? I would of thought this is very unlikely especially if it goes into a learn cycle when a battery is reconnected. The plot thickens......
Just an additional thought. When I get my 160w solar and Renogy DC-DC up and running it should trickle charge the van battery after the leisure battery is topped off. If I park my van up for a week or two I don’t anticipate it throwing a hissy fit because the SOC is different to the last time it was started?
No, because the battery shunt on the van will monitor the solar/dc-dc incoming charge 24/7, as well as any power drain like LED lights etc.
The EMS is active 24/7 its one of the reasons the van battery wont last 4weeks just sitting there,
well that and the alarm system,
and the immobilizer system,
and the CAN_Bus etc etc . . . .
