I know this is not really the right Forum , but it does relate to Carista, and I had some good help when I first started with my Skoda. Can any one tell me if I can recode a battery with the Carisata please. Cant find anything on their site. I am changing a battery on a Golf MK7 and have been told it should be recoded . I cant really see why ? surely the ECU will learn the new battery ? Any help on this would be gratefully received.

 

 

Never heard of a battery being 'coded' to a car, just remove and replace

7 minutes ago, Black vRS Oct said:

Never heard of a battery being 'coded' to a car, just remove and replace

 

Not sure of this applies to many mk 2 octavias, but if the car has start/stop it is classed as a micro hybrid class 1 (class 2 if it also has energy recovery via alternator). It will then have an EFB or AGM battery and intelligent battery management. These cars require the correct coding of the battery to the cars systems. You'll need to recode unless you choose an identical replacement (type, manufacturer, part no, ah capacity), failure to do so may lead to the new battery having a short life, and/or issues with stop/start.

A MK3 Octavia is closer to a MK7 Golf as both are MQB.

 

That aside, you should probably try and follow the VCDS guide as it should be a similar procedure: http://wiki.ross-tech.com/wiki/index.php/Battery_Replacement

 

Thanks for all the replies, had a lot better support here than the Golf Forum. I have emailed Carista to ask if they support battery re coding. Will keep you posted. I am sure as cars move on things like this are going to get more prevalent. Have to say I dont use the Stop Start, when I drive the Golf , as I find it a pain.

Just back from a lecture given by Yuasa Batteries and it supports everything pasted above by xman. Many interesting points made but one that caught my attention is that if you put in a new battery of old style flooded cells into a car with stop start that needs an AGM coded battery, the new battery will only last a few weeks.

These newer batteries are considerably more expensive too, starting at around £220 on medium size cars and going to twice that or more on large saloons. Plus the fact that the battery needs coding in and on one particular car the cost is over £800 at a main dealer as a front seat needs to be taken out to gain access, new one time bolts used and everything seat related re-tested.

 

I have the full version of the Carista app but when you use it, it only shows things that are relevant to your model of car. As mine uses a flooded cell battery the question of recoding does not apply so is not shown.

 

It also said this evening that we will all now be moving to the new battery type if we buy a new car as the EU has recently made stop start a requirement PLUS made it illegal to have a switch or other means of turning off the stop start on new models.

 

All done in the name of reducing emissions.........but that is another story.

17 minutes ago, pikpilot said:

These newer batteries are considerably more expensive too, starting at around £220 on medium size cars and going to twice that or more on large saloons. Plus the fact that the battery needs coding in and on one particular car the cost is over £800 at a main dealer as a front seat needs to be taken out to gain access, new one time bolts used and everything seat related re-tested.

 

Shop around!

 

EFB battery for my superb 3

https://www.tayna.co.uk/car-batteries/exide/el600/

Or AGM

https://www.tayna.co.uk/car-batteries/exide/ek600/

 

I guess that £800 example is something exotic, and not a Skoda.

 

Yes the EU are make non overridable stop/start compulsory!!!

Thanks for this. I had been in touch with Tanya who I normally use and yes they are considerably cheaper than  £220  with a good selection, I have contacted Carista and they do not support battery coding, which is disappointing, apparently OBD Eleven does , so will have to have a look at this.

9 hours ago, pikpilot said:

if you put in a new battery of old style flooded cells into a car with stop start that needs an AGM coded battery, the new battery will only last a few weeks.

Did they say why?

Its because an AGM requires higher voltage to charge and is allowed to discharge much deeper than conventional wet cell battery and the coding will adjust the charging scheme accordingly.

 

A conventional battery will get cooked when over charging losing water, and sulphate irreversibly when deep discharged, and frequent stop/start damages/strips the thinner plates (the thickness determines the cycle life).

 

EFB is much closer to old conventional batteries but have thicker plates and carbon additives and has a scrim between plates that reduces irreversible sulphation.

 

Hence coding matters...

 

https://batteryworld.varta-automotive.com/en-gb/car-battery-type-agm-efb

Edited 26 September, 20187 yr by xman

Xman has answered all the technical questions.

The £800+ example was quoted as a large Audi. Could be a Q7 from something else he said earlier.

Another point made is that the latest cars have a battery monitoring device on the negative battery cable. It send battery Voltage and current information back to the ECU. In conjunction with a smart alternator or combined alternator-generator, the ECU can then control alternator load to minimise emissions, choosing when to recharge the deep discharge capability battery. The battery also needs to support things like heated seats and windows for longer when this strategy is used. 

 

The price of £200 quoted above includes fitting and re-coding by a main dealer and some car service places. The battery itself can be bought for less. It takes about 10 minutes to do the re-coding but some places are already saying that any action that requires a software read or update through the OBD port is subject to the standard one hour charge they make for reading fault codes.

Indeed they do. Hence now looking at OBD Eleven, which looks like it will do it. Surprised Carisata do not support it.

46 minutes ago, pikpilot said:

Xman has answered all the technical questions.

He hasn't said why the AGM battery needs/can tolerate a higher charging voltage, nor why you might want to let the battery  get into a deeply discharged state (surely a battery management system should be there primarily to avoid such a situation?).

 

So Yuasa did or didn't explain the why?

Edited 26 September, 20187 yr by Wino

13 minutes ago, Wino said:

He hasn't said why the AGM battery needs/can tolerate a higher charging voltage, nor why you might want to let the battery  get into a deeply discharged state (surely a battery management system should be there primarily to avoid such a situation?).

 

So Yuasa did or didn't explain the why?

 

I can't comment on the higher battery voltage.

The physics of the AGM cell allows regular deep discharge to 50% without reducing life. The current automotive flooded cell needs to recharged when capacity has reduced by 10%. These figures are from a slide that was shown but no explanation about the surprising 10% other than it reduces sulphation and extends life. Of course there is no, or only simple, battery management system on flooded cells.

 

The strategy on newer vehicles seems to be let's use the deep discharge capability of the newer batteries to support the load when we want to reduce engine load to meet emission requirements. The batteries were developed for stop start duties and can meet 60,000 stop/starts in their lifetime. Minimum lifetime is five years so expect battery replacement to a major cost concern in future.

I think 5 years is very optimistic for OEM batteries. VW have been fitting an EFB ( which is the poor relation ) made by Moll to their spec. They are only 59Ah, and a huge amount of Golf drivers have only just got 3 years out of them. I sure this would be more prevalent if you live in a built up area and run the stop/ start function, as it will be on and off like a YoYo. All the more reason for me to keep my MK 2  4*4 daily driver until the wheels fall of . I rate it as one of the best all round cars I have had , and I have had a few.

OBDeleven pro its is , does the battery recode.

On 26/09/2018 at 11:49, Wino said:

He hasn't said why the AGM battery needs/can tolerate a higher charging voltage, nor why you might want to let the battery  get into a deeply discharged state (surely a battery management system should be there primarily to avoid such a situation?).

 

So Yuasa did or didn't explain the why?

 

Agm chemistry and construction requires higher charge voltage, it just does. About 0.3 volts higher. It allows AGM to recharge very quickly which is important for energy recovery (see later). Charging at conventional voltages leads to them not being fully charged ever and shorter life.

 

Micro hybrids (virtually all new cars today) use electrical load management and energy recovery, to reduce emissions. 

 

You accelerate and the alternator is turned down so you get performance boost/reduced fuel consumption/lower emissions. When you are on the overrun or braking (in gear) the alternator is whacked up and recovering energy into the battery. Energy that is free and can be used later. And so on. And for energy recovery you need capacity to dump that energy so the battery is normally held in a partial discharged state typically 70 -80%.

 

Only EFB and AGM can survive this kind of use.

 

Yes there is a sensor on the negative terminal that continually measures current going in/out of the battery. Its the same scheme as with all modern battery operated electronics such as your mobile phone. Its called coulomb counting, and the way the battery manager keeps track of the state of charge reasonably accurately.

 

Always important to note how to connect a charger, as per manual, use the special negative ground point on the vehicle and not the negative terminal on the battery.

 

2015-11_Batterie_efb-agm.pdf

Edited 28 September, 20187 yr by xman

10 minutes ago, xman said:

Yes there is a sensor on the negative terminal that continually measures current/voltage going in/out of the battery. Its the same scheme as with all modern battery operated electronics such as your mobile phone. Its called coulomb counting, and the way the battery manager keeps track of the state of charge reasonably accurately.

 

Is the battery management module design/function covered in any Skoda or VW SSPs, do you happen to know? I had a quick look yesterday on erWin but didn't spot anything obvious. It's probably buried somewhere within one with a different title.

Wonder if anyone's done a cut-down on one to see how it's implemented? I'm generally of the opinion that VW group tend to claim super-sophisticated systems and then actually implement rather basic versions of them in almost all of their cars bar the very top-of-the-range.

 

14 minutes ago, xman said:

it just does

Thanks for the explanation!

 

45 minutes ago, Whizzkid said:

OBDeleven pro its is , does the battery recode.

 

Glad you've got a solution.

17 minutes ago, Wino said:

 

Is the battery management module design/function covered in any Skoda or VW SSPs, do you happen to know? I had a quick look yesterday on erWin but didn't spot anything obvious. It's probably buried somewhere within one with a different title.

Wonder if anyone's done a cut-down on one to see how it's implemented? I'm generally of the opinion that VW group tend to claim super-sophisticated systems and then actually implement rather basic versions of them in almost all of their cars bar the very top-of-the-range.

 

Thanks

 

For the Octavia ,item 35 shown Here

 

If your wondering, its built into the negative terminal connector.

 

Here's a clearer pic of a similar unit

 

 

And a more in depth explanation

https://batteryuniversity.com/learn/article/how_to_monitor_a_battery

 

More about AGM for Wino 

https://batteryuniversity.com/learn/article/absorbent_glass_mat_agm

On 26/09/2018 at 13:14, Whizzkid said:

I think 5 years is very optimistic for OEM batteries. VW have been fitting an EFB ( which is the poor relation ) made by Moll to their spec. They are only 59Ah, and a huge amount of Golf drivers have only just got 3 years out of them. I sure this would be more prevalent if you live in a built up area and run the stop/ start function, as it will be on and off like a YoYo. 

 

I agree. So why do EFB and even AGM fail so early? Well certainly frequent stop/start and frequent deep cycling with aggressive energy recovery doesn't help, but there is another factor.

 

Unfortunately, with all battery management systems, there are several factors they cannot measure directly such as self discharge and complex temperature characteristics all of which vary with state of charge, age etc. and vary with individual cells/batteries.  So all the software can do is estimate and adopt various calibration strategies but over time the real state of charge gets way out of sync. This is where it all starts going wrong and the battery starts to suffer when battery management turns into mismanagement.

 

I suspect an occasional full recharge with an good quality external charger can help reset/recalibrate things and should lead to a longer life.

 

Thanks xman, I'd already seen the AGM BU page and almost quoted it at you in context of charging voltage, where it seems to say that 2.4V/cell (14.4V post-to post) is fine, (but faster charging can happen if you give it a bit more). Mustn't maintain that 14.4V or more if/when it's fully charged though, which presumably the management module can have a guess at and let the alternator know to back off a tad.

Interesting that they say:

"AGM and other sealed batteries do not like heat and should be installed away from the engine compartment.  Manufacturers recommend halting charge if the battery core reaches 49°C" 

Perhaps another reason for short lifespan?