All VW EVs recalled as the 12V battery can't handle an OTA update

unkel · 06-04-2022 6:03pm #1

All ID.3, ID.4 and presumably all the other makes and models that share the MEB are to be recalled to have a new lead acid 12V battery fitted free of charge. The current batteries do not have enough capacity to last through a full OTA software update.

Reads like an April fool's day prank message. How big are these updates that they require what, 300Wh or so of energy to complete? That's the equivalent of a modern office PC doing a full days work.

fits · 06-04-2022 6:11pm

Old news Unkel. We’ve known about this for months.

unkel · 06-04-2022 6:44pm

https://www.boards.ie/discussion/comment/118890313#Comment_118890313

I only heard about it today and as far as I can see there was no specific thread about it. But I take your word is was probably mentioned somewhere in the ID.3 or ID.4 threads (which I don't follow regularly)

Still, deserves its own thread imho. 12V batteries can generally be troublesome in EVs unless they are monitored and topped up properly from the main high voltage battery (even when the car is off)

Interesting to see if anyone has the technical details of the old and the new batteries that will be fitted. I don't think any have been replaced yet?

markpb · 06-04-2022 7:08pm

Maybe a dumb question but how are these related? I presume the BMS is responsible for monitoring the state of the 12V battery and turning on the DC to DC Converter to draw power from the HV Battery? Does the BMS not run for the entire duration of the software upgrade?

Ubbquittious · 06-04-2022 7:12pm

https://www.boards.ie/discussion/2058240567/all-vw-evs-recalled-as-the-12v-battery-cant-handle-an-ota-update

What kind of office PC is that? A raspberry pi?

the_amazing_raisin · 06-04-2022 9:04pm

https://www.boards.ie/discussion/2058240567/all-vw-evs-recalled-as-the-12v-battery-cant-handle-an-ota-update

Not true, the 12v batteries are being replaced with a different chemistry and they're patching the BMS to allow updates as part of this

The issue with the 12v is that they're seeing a lot more cycling of the battery than the original battery was specced for. I think the current battery is AGM, the new one is an enhanced flow battery, which I think is a bit lower power but can take more cycling

The software update is because the BMS currently can't be updated remotely, it needs a manual update to fix that and the charge timers, as well as make the battery heating a bit less power hungry

unkel · 06-04-2022 9:18pm

https://www.boards.ie/discussion/comment/118890592#Comment_118890592

A modern office PC uses about 40W. Times 7.5 hours working day = 300Wh

A Raspberry Pi uses about 5W

I suspect you roughly know these figures but being deliberately obtuse. But maybe I think too highly of you.

unkel · 06-04-2022 9:32pm

https://www.boards.ie/discussion/comment/118891093#Comment_118891093

That all sounds a bit vague if you pardon me for saying so. Would be great if we could get a few links in here with more details, I did a quick Google but can't find much.

Until I see some more specifics, I find it hard to believe the problem is with the physical battery. Sounds more like poor software to me. Very much like the early Hyundai Ioniq where the 12V lead acid battery was also problematic. There was a system in place where the 12V was monitored and topped up by the HV when needed. But this monitoring was not done in an appropriate and timely way. Play around with the heating system long enough with the car switched off and the 12V would be dead (just like in any ICE car). While if the HV had been constantly monitoring the 12V, this would not have happened. In other words, a software problem. Still not addressed. I hear you say VW / Hyundai combined have hundreds of thousands of employees, many of them electrical engineers with high quality degrees. And here is this unkel lad from the internet who has played with batteries for a few years as an amateur. But nothing surprises me at this stage. In some ways EVs are very different from ICE cars which seems hard to comprehend for behemoth incumbent ICE manufacturers, new to making EVs.

handpref · 06-04-2022 9:48pm

Old build id3’s or early December 2021 cars with 2.1 have a 280A (51ah) battery.

Revised id3 (with park assist) with July 2022 build date has a 320A (49ah) battery and factory 2.3 according to my vw build info.

Thats working off the build date on the car I ordered last August which has a July 2022 build date and one which the dealer had ordered earlier and has kindly offered to me to help move things on.

the_amazing_raisin · 06-04-2022 10:04pm

https://www.boards.ie/discussion/comment/118891286#Comment_118891286

Well the exact details of the service campaign haven't been released but the battery chemistry change is confirmed. What we've heard so far is that it's because the 12v is being cycled more than expected and the lifetime is being shortened

Shirt story, VW probably used whatever batteries they had in stock and it wasn't the best plan, they're more suitable for ICE card

The ID.3 had a software issue early on where the 12v wasn't getting charged often enough, they fixed that fairly early on. I think there were a few reports of people getting dead 12v over winter but didn't seem worse than any other EV in winter

ted1 · 06-04-2022 10:27pm

https://www.boards.ie/discussion/comment/118891286#Comment_118891286

They are replacing 51Ah batteries with 49Ah batteries, that puts to bed your logic that they are not big enough.

the update is for some cars that gave 2.1 as it can’t be upgraded. It’ll the car has 2.3 no manual update needed.

Ubbquittious · 06-04-2022 10:32pm

https://www.boards.ie/discussion/comment/118891189#Comment_118891189

The more recent Pi uses a 3A supply. I was thinking one of those running the whole day.

Wouldnt mind a job in the 7.5 hours a day place

unkel · 06-04-2022 10:51pm

https://www.boards.ie/discussion/comment/118891631#Comment_118891631

That depends. A 49Ah LiFePo4 has nearly double the usable capacity of a 51Ah Lead Acid battery ;-)

In other words, your argument is nonsense until we know what chemistries are used.

unkel · 06-04-2022 10:54pm

https://www.boards.ie/discussion/comment/118891673#Comment_118891673

The max amperage / power of a power supply is not directly related to how much the system draws. I have a high quality 850W PSU in my PC, yet it uses about 40W in normal light (office) use.

unkel · 06-04-2022 10:58pm

https://www.boards.ie/discussion/comment/118891475#Comment_118891475

If both are still just Lead Acid, there isn't an awful lot of improvement in number of cycles. For most Lead Acid a few hundred cycles is about the height of it. And even in an ICE car this is plenty as the battery is mostly only cycled between 90% and 100%. I have no idea why this this can possibly be a hardware problem. If the HV would continuously top up the Lead Acid 12V, the battery would last the same 3-5 years it does in an ICE car no problem. My guess is that somehow VW can't or won't make this happen (like Hyundai). I maintain it's a software issue, unless someone can make a good case for this being indeed a hardware issue.

the_amazing_raisin · 07-04-2022 9:36am

https://www.boards.ie/discussion/comment/118891809#Comment_118891809

Well that's what has been publicly announced, you can take it or leave it as you will but if you're not going to believe any of the answers you've gotten then why ask the question? 😜

Deiss is on Twitter and LinkedIn, why not go over there and ask him directly, get some answers for us 😉

unkel · 07-04-2022 9:49am

https://www.boards.ie/discussion/comment/118892679#Comment_118892679

I'd like to see some more details than that vague story that doesn't make sense for the reasons I outlined. I'm a bit surprised that everyone else in here just takes whatever VW says as gospel.

It's quite well known / accepted that the issue with Hyundai was similar and led to many lead acid batteries having to be replaced under warranty. While the problem could have been prevented by a small software change. Well known as in concluded on various forms. Never officially accepted by Hyundai though as far as I know 😂 And for the sake of clarity, I owned said Hyundai when this issue was around. It almost happened to me when one of my kids was playing around with the heating and music in a parked car and the car almost failed to start because it had drained the 12V battery. I got lucky so it didn't kill my battery. Now this of course is par for the course with any ICE car and always has been. But with an EV this doesn't need to be a problem any more, if people had a fundamental insight into what is different. It seems incumbent manufacturers don't. Funnily and maybe not surprisingly, Tesla does. Their cars are always on, so the 12V battery can never be drained (unless of course you run into physical problems like that the HV battery is drained so far that it can no longer top up the 12V)

[Deleted User] · 07-04-2022 10:26am

If it's well known and accepted on the internet, then it's likely not true.

celtic_oz · 07-04-2022 10:41am

It seems incumbent manufacturers don't. Funnily and maybe not surprisingly, Tesla does. Their cars are always on, so the 12V battery can never be drained (unless of course you run into physical problems like that the HV battery is drained so far that it can no longer top up the 12V)

didnt James May have a fairly public issue with his Tesla battery draining, something about it reaching 100% charge and plugged in

https://www.youtube.com/watch?v=NsKwMryKqRE

though probably remediated in a software update by now

Paul Kiernan · 07-04-2022 11:48am

Traditionally an ICE car ran the alternator and applied 14v to the lead acid battery when the engine was running.

My assumption is that my Ioniq 5 doesn't do this because most of the time it's not necessary and would just waste energy. It therefore monitors the battery (in software) and only applies the charge when required. As I'm not confident it does this properly I now carry a 12v powerpack with me!

I've no idea about the VW's.

zg3409 · 07-04-2022 12:38pm

https://www.boards.ie/discussion/comment/118893323#Comment_118893323

This is a voltage log from my ioniq 28kWh. (Actually not my car, but similar)

There was updates made to the car to try reduce failures, but same issue exists on Kona and presumably niro. As unkel said to save "phantom" drain on main battery the "computer" only wakes up now and then and if needed tops up 12 volt battery. I am on battery #3 after 12 years and I have a jumper pack ready to go.

With VW it may be software and hardware issues. The concern I would have it that typically 12 volt batteries only have 2 years warranty so unless they actually fix the root causes owners will continue to have issues when batteries are out of warranty and a long term fix may never happen (like is the case on Kona/niro etc. )

eagerv · 07-04-2022 1:57pm

I see it as a positive that VW are changing the battery, though never had any problem with the old one in my previous ID.3. Tesla did something similar, though changing to a Lithium 12V.

unkel · 07-04-2022 2:22pm

Yes and as @zg3409 rightly points out, the main drawback of an "always on" system like Tesla's is of course that it does use up energy. This causes the so called "phantom drain" which I always found a curious name as it is pretty clear what is causing this drain, nothing phantom about it. Unless you really don't understand how these systems work.

unkel · 07-04-2022 2:43pm

@celtic_oz - that doesn't make sense. Must have been an issue on that particular car with the HV not charging the 12V. In Teslas this is normally done automatically as the car is always on.

Interestingly - and on subject - Tesla now fit all their cars with lithium 12V batteries. These can go far lower voltage than lead acid and still do the job. Also makes the cars a good 10kg lighter. I haven't found yet exactly what chemistry they use for it, the tech guys in Tesla Dublin didn't know.

eagerv · 07-04-2022 3:37pm

https://www.boards.ie/discussion/comment/118894126#Comment_118894126

The drain doesn't seem too bad on my new LFP battery providing you don't leave Sentry mode on and you don't interrogate the car too often with the app. Appears to be around the 1% every 2 days or so, which is similar enough to my old ID.3. Like the ID.3 it appears to go into somewhat of a sleep, you notice it with my Model 3 when it takes the app about 20 seconds or so to opearate if hasn't been used for a while.

ewj1978 · 14-04-2022 9:30pm

Had my May 21 Id3 in the dealers last week. Asked them about the recall. Zero news. Never heard about it.

All VW EVs recalled as the 12V battery can't handle an OTA update

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