Coding replacement batteries.

[Pugglt Auld Jock]

I've previously posted about stop start and the wee battery monitor module, linked of course to a computer somewhere in the vehicle, and how you have to be careful about where you connect in either a charger (smart charger only please) or jump starter when a vehicle is equipped with one of these - and if you've got stop/start it probably does.

Well My Ibiza has this setup and it's battery has been very slowly dropping off in performance for some time now. I've been meaning to do something about buying a new battery for some time but put off because a) it was still starting and running Ok(ish) and b) the new battery has to be coded to the car so, in theory, you need to get a main agent, or competent indy, to do it for you. You also need to buy a battery with the BEM code sticker on it so you have the info needed to code it in:

There are claims about that you can use VAG-COM (VCDS), which I have, to alter the coding so you can use a non BEM coded battery (thus saving a shed load of money by buying from such as Tayna) but I never really understood what you needed to do. The main agent and all 3 indies up here in Edinburgh were quoting around £230 to £260 to supply and fit - I was pleased to see it was my favourite AVW who quoted cheapest price - but as she was still running fine and staring Ok(ish) I stupidly did nothing about it before we set of some 3 weeks ago to visit both daughter and family near Salisbury and then over to Mrs J's sister up near Exmoor in the hills behind Barnstaple in Devon.

The car ran beautifully all the way down on it's brand new Falken tyres and returned the usual 60mpg but on E10 petrol for the first time - saw no change in consumption at all which surprised me? Spent a week with daughter and her family - a week is probably just about right with 2 teenagers! - then over to sister in law in Devon. 2nd day there she was very slightly slow on the crank but I didn't think anything of it as she fired up quickly and ran fine. Next few days she seemed fine but then I didn't use her for a couple of days and she barely started on the Friday. Luckily I'd taken my CTEK smart charger so I put her on charge over night and she started Ok on the Saturday but cranked a bit slow. I let her sit for a couple of hours when we returned to the house (to allow plate surface charge to dissipate) and she was showing 11.9 flickering to 12 volts on my multimeter. B****r! New battery needed without a doubt!

So I rang the nearest Seat Main agent - Croyde Motors: https://www.croydemotors.co.uk/ - explained my situation and what I'd observed with the battery and could they supply fit and code a new one in time for us to set of back home the following week. I've copied the garage's website above because I've been so pleased with their response. Not surprisingly they don't hold batteries in stock but could get one next day. Did I realise this needs to be a "proper" VAG battery due to the need for it to be coded? Yes I did. And the cost? Well, as I'm completely unknown to them and they are unlikely to ever darken their door again, I was expecting a "maximum possible" price, but no, £250 all in coding, subsequent check for DTC's following coding and running and VAT. Pretty much what I would have paid at home. Of course being a main agent I have a national 2 year guarantee valid at any SEAT agency.

If you come in first thing in the morning we'll do it while you wait. I was on their door at 08.30hrs yesterday and back on the road just over half an hour later with a wallet £255 the lighter - something to do with the VAT? - thank goodness for credit cards! The garage was quite small, showroom only big enough for 2 cars and their new electric scooter, more like a family type business than a main agent. Chris, the chap who dealt with me was exceptionally nice and even allowed me to go round into the workshop to speak with the chap who did the work and take a couple of photos of the old battery which was bulging out on one end due to swelling of the sulphated plates. I'd been speaking to Chris at the reception desk and mentioned that I did my own services and some repairs and he made sure they checked the car for updates to software free of charge which I greatly appreciated as this has not been done, due to me doing home servicing, since it came out of warrant over 3 years ago. No updates were found to be needed.

The difference in cranking speed is very noticeable - no great surprise there - and stop start is again now available right from the turn of the key - although I still cancel it when I remember, in deference to the starter and turbo amongst other components. I'd opened the bonnet and had a quick "shufty" at it before driving away from the garage but, once back at wife's sister's house I gave things a more in depth examination and I have to say I'm very impressed. The battery is fitted very nice and square into the little ledges which hold against the bottom fixings and the clamp is positioned nice and square on to the battery (it's been squint from the day I bought it new) The clamps are properly pushed fully onto the posts and the clamps haven't been overtightened to the extent that the clamps are distorted - something I've often seen when replacement batteries are fitted by less skilled fitters. I like to use Holts NoCorode on the terminals and clamps and it could be plainly seen that a similar product had been sprayed over the clamps and posts on the new battery. The whole job just couldn't have been done better. Then I noticed a wee white plug in the top of the battery facing the engine:

That looks like a vent plug to me - they fit these to stop electrolyte leaking when the battery is being transported but they are normally removed when the battery is fitted to a vehicle - Oh dear. However then I looked at the other end of the battery, which faces the N/S inner wing and:

Oh, just a hole, no plug. Wonder if they just forgot the other one? maybe I should just remove the other one? Oh but maybe I shouldn't because they were so good and gave such attention to detail surely they wouldn't have forgotten this? So, today I rang Chris and asked him, apologizing for wasting his time with such a mundane query. He was very nice and said it was no waste of time to keep a customer happy. Yes only the vent plug nearest the inner wing is opened to avoid the possibility of combustible/explosive gasses being directed towards hot engine parts. So that plug on the engine side of the battery should remain installed - so glad I rang.

So I'm now set for another 6 years, hopefully longer, before I need to worry about the battery again. I'm going to keep a very careful eye on voltages if I don't plan to use the car for more than a couple of days and probably couple up the CTEK more often.

Many of you will know I'm interested in exploring these "finer details" about our cars. I've been especially interested in inlet carbon fouling on direct injection petrol engines recently and found a lot of stuff on line and you tube about it. Tyres is another area of particular interest. Now I'm going to get into what all this battery coding is all about and try to find a reliable way round it. I'll come back on this subject if I manage to make any headway.

 

[portland_bill]

A shame you had to replace it when away from home, as self-help options disappear at those times.

Euro and others list replacement batteries for VAG vehicles, without any reference to coding, so presumably many workshops are fitting these somehow. My Fabia battery is not in the greatest of health, but cranks enthusiastically, even though generally only used on Wed & Thu each week. On the Wednedsay, often the stop/start will only operate after the first run, not during, so it seems to take some time to revive.
Some time ago, I researched a replacemetn battery, and emailed Yuasa about recoding. This was their response: "The BEM code is a dealer only code that does not appear on our product, as we are not affiliated with VAG (Volkswagen/Audi group). A workaround for this is to have the battery coded with a Yuasa YuFit battery configuration unit (a service available from some of our distributors) or continue with the BEM code method. This involves recycling the number from the old battery and incrementing the last digit by 1 when conducting the recoding procedure."

I've delved into the OBDeleven support forum, not as easy as this forum, and have found their response to a similar question. Aparently, the recoding only really tells the management module that a new battery has been fitted, and it will start afresh with its monitoring. Manufacturer and serial number not important, as the module does not contain any data on that, it justs starts again. Seems the serial number might just be to keep battery replacement 'in-house'.
We may find out if all this is true when mine gives up.

 

[Pugglt Auld Jock]

A shame you had to replace it when away from home, as self-help options disappear at those times.

Euro and others list replacement batteries for VAG vehicles, without any reference to coding, so presumably many workshops are fitting these somehow. My Fabia battery is not in the greatest of health, but cranks enthusiastically, even though generally only used on Wed & Thu each week. On the Wednedsay, often the stop/start will only operate after the first run, not during, so it seems to take some time to revive.
Some time ago, I researched a replacemetn battery, and emailed Yuasa about recoding. This was their response: "The BEM code is a dealer only code that does not appear on our product, as we are not affiliated with VAG (Volkswagen/Audi group). A workaround for this is to have the battery coded with a Yuasa YuFit battery configuration unit (a service available from some of our distributors) or continue with the BEM code method. This involves recycling the number from the old battery and incrementing the last digit by 1 when conducting the recoding procedure."

I've delved into the OBDeleven support forum, not as easy as this forum, and have found their response to a similar question. Aparently, the recoding only really tells the management module that a new battery has been fitted, and it will start afresh with its monitoring. Manufacturer and serial number not important, as the module does not contain any data on that, it justs starts again. Seems the serial number might just be to keep battery replacement 'in-house'.
We may find out if all this is true when mine gives up.

Thanks PB you've pretty much supported what I thought I'd understood there. It's all about "resetting" the ECU so it starts at the beginning of it's battery assessing program which, I think, modifies charging as the battery degenerates and restricts what features, like stop/start, can be used so as to ensure as far as is possible that the car's engine can be started for as long as possible as the battery degenerates. I suspect the module itself couldn't care less about the battery serial number or who the manufacturer is etc, but might be interested in stuff like capacity (ampere hours and the like?) and whether it's EFB or AGM. I've been in conversation with a chap on the Cupra forum who lives quite near me and he is experimenting with VCDS on his wife's (or is it daughter's) Polo as it's going to need a new battery very soon. I'm hoping he will be able to advance the knowledge base for us. It's just occurred to me, I've got a picture of the old BEM detail sticker and one from the new battery, maybe I should compare them and see if there is any significant similarity which might rule out the importance of any particular number field. Off to do that now.

Edit - about 5 minutes or so after the above - Just compared the 3 long strings of numbers and, whilst there are similarities there are also significant differences in all 3 numbers. Giving this up for tonight as I've got a good book to read and my wife's sister needs the bulbs changed in her electric fire - flame effect. I'm "on the case" now though and I'm not giving up on it.

 

[DaveMcT]

"Manipulating" this code looks like a great way to disrupt the auto stop/start greenwash.

 

[Pugglt Auld Jock]

"Manipulating" this code looks like a great way to disrupt the auto stop/start greenwash.

Hmmm. Now that's an interesting thought Dave. I think it would indeed "disable" stop start - which personally I would welcome. I talked to quite a number of people up here trying to understand about it and I'm sure I've not yet got to the bottom of it yet. However, So far I think I understand that on my vehicle, which has a "smart" (Oh dear I do hate to see that word because it seems to be "code" for "something complicated which will probably go wrong/cause aggravation") charging system The battery monitor (that wee "gizmo" on my battery's negative terminal clamp) is continuously feeding the ECU involved in controlling the alternator field, info about how the battery is behaving during charging and discharging and also what it's standing voltage is. It - the ECU - then modifies the current being fed to the alternator field, thus varying alternator output, to achieve the best charging scenario for the battery condition as it ages. I also "plays" with charging anyway by cutting the field excitation during acceleration so the alternator "eats" less engine power during acceleration and greatly increases field strength under trailing throttle so the alternator can consume engine power which otherwise is wasted. The problem with this recoding malarky is that if you fit a new battery without telling the ECU that you've done so then it goes on trying to charge the battery on the last info it's got stored - which is likely to be for a considerably suphated battery like mine was. I'm guessing this means the alternator may be overcharging the now good battery which will have lower internal cell resistance? I was told it's to be expected that the new battery will fail prematurely if this recoding is not done, in extreme instances that might be after just a year to 18 months I've heard.

The fella who lives near me just south of our lovely city is still experimenting with his Polo (mine's the almost identical Ibiza version) His opinion is that the car's ECU is not interested in most of the info asked for on the settings fields (3 of them in VCDS) but is interested in stuff like CCA and battery capacity (amp hours). Anyway, He tells me he's still experimenting and will come back to me if he gets to any concrete solution - All a little late for me now I've got my expensive genuine VAG (but really a Varta) battery complet with it's genuine dealer recode. But, as this is not a "problem" which is going to go away and will probably be there on other cars bought by family members, any info he can pass on to me will be most gratefully received!

 

[DaveMcT]

It's interesting how starter batteries on "dumb" alternators could last at least 5 years. Yet today the same battery technology** can't handle 12 months without a fancy computer controller.

** Lead acid chemistry is the same regardless of "AGM" or whatever TLA they use in the marketing.

 

[chris3234]

It's interesting how starter batteries on "dumb" alternators could last at least 5 years. Yet today the same battery technology** can't handle 12 months without a fancy computer controller.

** Lead acid chemistry is the same regardless of "AGM" or whatever TLA they use in the marketing.

Modern cara also draw far more power then older cara especially with start stop

 

[portland_bill]

It's interesting how starter batteries on "dumb" alternators could last at least 5 years. Yet today the same battery technology** can't handle 12 months without a fancy computer controller.

** Lead acid chemistry is the same regardless of "AGM" or whatever TLA they use in the marketing.

Some research I participated in a few years ago, before start/stop, showed that if a batttery was fresh when first fitted, it could be expected to last about 7 years. One that was allowed to discharge in storage wouodl fail within the first 3 years. Getting stockists to keep stock fresh reduced the warranty claims by a huge amount. This life expectancy seems to be playing out with the current Panda and two previous classic Pandas, and a Seicento that had sat a bit before being registered new, that had a failure at just over 3 years.

The Fabia, start/stop, 'smart' charging system, and had sat a while on a forecourt before I bought it, is still on its original battery, at nearly 7½ years. (That'll jinx it, then I'll be experiencing the recoding challenge)
The stop/start was flaky when I first got it, only operating after a good run. Being mostly used just two days a week, (Wed/Thu), start/stop would be flaky on Wednesdays, but working fine on Thursdays. Now after 3 years, the stop/start seems to be consistent, and working well. So the battery appears to have revived, although it has taken half its life to do so.

Whilst lead/acid chemistry is basically the same, there is something different in some applications. Car batteries have to give a big push, to start the engine, then sit back and relax while the alternator does most of the work. They do not like 'deep cycling' from charged to flat, recharge, repeat. Leisure batteries, such as auxiliary batteries in motorhomes, propulsion for golf buggies and carts, power for lawm mowers, etc., are specifically designed for this deep cycling. A normal car battery (sometimes known as a 'starter' battery, will fail very quickly in a golf cart, and as an auxiliary battery in a motorhome, as many will testify having tried to save money. Similarly, a leisure battery used for starting the engine regularly, will also fail prematurely.

 

[DaveMcT]

Lead acid "Starter batteries" are built to deliver very high current. They will give a good kick but only about 30% of the capacity (Amp Hours) is usable. Half of the remaining 70% will only trickle out and the last 35% will probably brick the battery by taking it below the low voltage limit.
Deep cycle lead acid batteries will give about 50% at full current though the peak is considerably lower. After that you are in the same situation as an engine start battery. I suspect that starter batteries are more prone to hard sulphating by disuse.
It's a great shame that OEMs have been incapable of switching to LFP starter batteries. This type can fully use the charge capacity, does not degrade by disuse and these days are competitive on price. The solution to poor cold start performance in LFP is a few seconds across a heavy resistor to warm the battery. It will then keep on going when a (too cold) lead acid would have given up.

 

[DaveMcT]

By the way -
I replaced a 14AH starter battery on the BMW 1200 GS with an LFP. The battery on the bike was 5kg of 14AH Odyssey that alleged 500 CCA (though the starter cable would have never handled that much current). The starter motor looked identical to the ones used on Fiat Pandas.
The LFP was 4AH and weighed 0.8kg. It spun the starter faster than the Odyssey and less cost (£60 vs £100). The bike was getting less use so I needed a battery that did not need to be kept on a float charger (no power to my garage). LFP is great for that.
I tried the LFP on the Panda expecting it to struggle. Not a bit of it. The car started as normal and the electrics all worked fine from stone cold. It's a shame I dont have the ££s to risk wrecking a new LFP battery to see how long it would last in real use.

 

[portland_bill]

@Pugglt Auld Jock Just found this and thought you might like it.

 

[The Panda Nut]

I've previously posted about stop start and the wee battery monitor module, linked of course to a computer somewhere in the vehicle, and how you have to be careful about where you connect in either a charger (smart charger only please) or jump starter when a vehicle is equipped with one of these - and if you've got stop/start it probably does.

Well My Ibiza has this setup and it's battery has been very slowly dropping off in performance for some time now. I've been meaning to do something about buying a new battery for some time but put off because a) it was still starting and running Ok(ish) and b) the new battery has to be coded to the car so, in theory, you need to get a main agent, or competent indy, to do it for you. You also need to buy a battery with the BEM code sticker on it so you have the info needed to code it in:

View attachment 404989

There are claims about that you can use VAG-COM (VCDS), which I have, to alter the coding so you can use a non BEM coded battery (thus saving a shed load of money by buying from such as Tayna) but I never really understood what you needed to do. The main agent and all 3 indies up here in Edinburgh were quoting around £230 to £260 to supply and fit - I was pleased to see it was my favourite AVW who quoted cheapest price - but as she was still running fine and staring Ok(ish) I stupidly did nothing about it before we set of some 3 weeks ago to visit both daughter and family near Salisbury and then over to Mrs J's sister up near Exmoor in the hills behind Barnstaple in Devon.

The car ran beautifully all the way down on it's brand new Falken tyres and returned the usual 60mpg but on E10 petrol for the first time - saw no change in consumption at all which surprised me? Spent a week with daughter and her family - a week is probably just about right with 2 teenagers! - then over to sister in law in Devon. 2nd day there she was very slightly slow on the crank but I didn't think anything of it as she fired up quickly and ran fine. Next few days she seemed fine but then I didn't use her for a couple of days and she barely started on the Friday. Luckily I'd taken my CTEK smart charger so I put her on charge over night and she started Ok on the Saturday but cranked a bit slow. I let her sit for a couple of hours when we returned to the house (to allow plate surface charge to dissipate) and she was showing 11.9 flickering to 12 volts on my multimeter. B****r! New battery needed without a doubt!

So I rang the nearest Seat Main agent - Croyde Motors: https://www.croydemotors.co.uk/ - explained my situation and what I'd observed with the battery and could they supply fit and code a new one in time for us to set of back home the following week. I've copied the garage's website above because I've been so pleased with their response. Not surprisingly they don't hold batteries in stock but could get one next day. Did I realise this needs to be a "proper" VAG battery due to the need for it to be coded? Yes I did. And the cost? Well, as I'm completely unknown to them and they are unlikely to ever darken their door again, I was expecting a "maximum possible" price, but no, £250 all in coding, subsequent check for DTC's following coding and running and VAT. Pretty much what I would have paid at home. Of course being a main agent I have a national 2 year guarantee valid at any SEAT agency.

If you come in first thing in the morning we'll do it while you wait. I was on their door at 08.30hrs yesterday and back on the road just over half an hour later with a wallet £255 the lighter - something to do with the VAT? - thank goodness for credit cards! The garage was quite small, showroom only big enough for 2 cars and their new electric scooter, more like a family type business than a main agent. Chris, the chap who dealt with me was exceptionally nice and even allowed me to go round into the workshop to speak with the chap who did the work and take a couple of photos of the old battery which was bulging out on one end due to swelling of the sulphated plates. I'd been speaking to Chris at the reception desk and mentioned that I did my own services and some repairs and he made sure they checked the car for updates to software free of charge which I greatly appreciated as this has not been done, due to me doing home servicing, since it came out of warrant over 3 years ago. No updates were found to be needed.

The difference in cranking speed is very noticeable - no great surprise there - and stop start is again now available right from the turn of the key - although I still cancel it when I remember, in deference to the starter and turbo amongst other components. I'd opened the bonnet and had a quick "shufty" at it before driving away from the garage but, once back at wife's sister's house I gave things a more in depth examination and I have to say I'm very impressed. The battery is fitted very nice and square into the little ledges which hold against the bottom fixings and the clamp is positioned nice and square on to the battery (it's been squint from the day I bought it new) The clamps are properly pushed fully onto the posts and the clamps haven't been overtightened to the extent that the clamps are distorted - something I've often seen when replacement batteries are fitted by less skilled fitters. I like to use Holts NoCorode on the terminals and clamps and it could be plainly seen that a similar product had been sprayed over the clamps and posts on the new battery. The whole job just couldn't have been done better. Then I noticed a wee white plug in the top of the battery facing the engine:

View attachment 404994 so a good move - unless Im posting on an old post

That looks like a vent plug to me - they fit these to stop electrolyte leaking when the battery is being transported but they are normally removed when the battery is fitted to a vehicle - Oh dear. However then I looked at the other end of the battery, which faces the N/S inner wing and:

View attachment 404995

Oh, just a hole, no plug. Wonder if they just forgot the other one? maybe I should just remove the other one? Oh but maybe I shouldn't because they were so good and gave such attention to detail surely they wouldn't have forgotten this? So, today I rang Chris and asked him, apologizing for wasting his time with such a mundane query. He was very nice and said it was no waste of time to keep a customer happy. Yes only the vent plug nearest the inner wing is opened to avoid the possibility of combustible/explosive gasses being directed towards hot engine parts. So that plug on the engine side of the battery should remain installed - so glad I rang.

So I'm now set for another 6 years, hopefully longer, before I need to worry about the battery again. I'm going to keep a very careful eye on voltages if I don't plan to use the car for more than a couple of days and probably couple up the CTEK more often.

Many of you will know I'm interested in exploring these "finer details" about our cars. I've been especially interested in inlet carbon fouling on direct injection petrol engines recently and found a lot of stuff on line and you tube about it. Tyres is another area of particular interest. Now I'm going to get into what all this battery coding is all about and try to find a reliable way round it. I'll come back on this subject if I manage to make any headway.

This week forecast -6C tomorrow and freezing all week so a job well done I think.

 

[Pugglt Auld Jock]

@Pugglt Auld Jock Just found this and thought you might like it.

Thanks PB. I find this very interesting as it seems to imply that you don't need to know the BEM code - which is printed on the label with an "official" VAG supplied battery. I haven't been in conversation with the chap (who lives near me but I haven't met "in the flesh" yet) on the Cupra Forum for some time. He is, like me, trying to find a way round this BEM code problem. We both have VCDS (VAG-COM as it used to be) and that scan tool is still asking for the BEM code so I just wish the chap in the video had gone through his VCDS procedure stage by stage. What we do suspect though is that a good quality OBD type tool - such as the video chap is using - seems to circumnavigate the BEM code problem. We also think there are a number of tools in use by independent garages which probably get round this problem too. I'm going to ask the very helpful chap I know at Halfords next time I'm in there as they do a lot of battery renewals so must have a fix for the problem. By the way changing that last 1 to a 2 in the serial number seems to be accepted by VCDS. I think just increasing any number that appears in that spec box by a factor of one would work.

Now, having my new battery, this problem has rather taken a back seat on my priority list and you've reminded me that I've rather forgotten about it. I must get back on the trail. The new battery i just put in Becky was such a treat to do - simply unbolt the old one, clean everything up, install the new one reset the clock and off we went! Simples!

 

[portland_bill]

A while ago, I thought my Fabia battery was getting weak. I disovered this coding issue, but no mention of it when buying new batteries. So I asked Yuasa. Their reply was to just increment the existing code by one digit, which is what I think was done in the vid. The system just needs to be told it is a new battery, then it resets to a base, and measures from there, rather than charging the new battery like the old failing one.
Not coding could result in the new battery being overcharged, shortening its life.