Volkswagen ID.3 Forum

Went to open the car
Totally flat 12v battery
Something has drained the battery overnight
Has this happened to anyone else?
Dealer has had the car now for over a week

That doesn’t sound good! Let’s hope they sort it out but I think the dealers don’t really know what they are doing with id.3s...

Yes exactly
The dealer tells me they are testing and fault finding in Germany.
Hence the delays

Hi Hilly,

I too have the same issue, with my ID.3.

After a couple of days not using the car the 12 volt battery was drained, and the car was totally dead.

The key fob wouldn’t open the doors.

On opening the ID.3 with the emergency key, the car was non responsive; no lights, no sounds, nothing!

The car only came back to life after breakdown recovery, recharged the 12 volt battery.
The main high voltage battery was still at over 70% charge.

My VW dealership haven’t been able to identify any problems with the car; however, I don’t believe these are isolated cases.

See following you tube video



Stephen

A lot of people are experiencing this. If not driven my ID.3 depletes the 12V battery from 100% charge to ~60% charge after a couple of days. Apparently it is a software issue causing parts of the car to not always fully power down thus draining the 12V battery. So eventually there should be a fix in some upcoming software update. Until then check your battery and charge it regularly

Chris (in the YouTube video) posted an update this morning:

"I have my appointment for the Id.3 12V problem software update. Next tuesday. I bring them the car in the morning. I get a dealer car and pick it up in the afternoon."

This is certainly bad news re 12v battery drain.

I would be interested to know what software version your car is running at now and what it is when you get the car back.


A

Hi,
I have a question for those people who's 12v battery was drained when the car was not used for a couple of days.
How close to the car did you keep the keys?

My ID3 is parked with the bonnet just under my study window. The keys are kept out of sight in the study. Last night I picked up the bunch of keys with the ID3 fob to lock the front door. Through the study window I saw the ID3's lights come on as if I was going to get into the car, I wasn't. Looking at the key fob there was a small red LED flashing all the time, is the car communicating with the fob all the time it is in range and is this draining the 12v battery? I had to walk a further 10m away from the car before the LED stopped flashing. If you kept your keys 15 metres away from the car while the 12v battery drained then my little theory is blown, please let me know.

Silver

The way the keyless entry works is that yes, the car broadcasts a radio signal, and the key replies if in range - however this would be a very low power signal, and it is unlikely to be enough to drain a lead-acid battery in a couple of days. Keeping the keys close to the car may however drain the small button battery inside the key fob faster than you might like (eg A few months)

This topic (over active keys) was discussed a lot in the ID.3 First Movers forum and while it may have small impact it seems unlikely it is the main culprit. The rumour from VW is that the 12V battery drain is due to a software issue in the CAN-Bus controller which results in some components not properly powering down when they should. This has not been officially confirmed however.

For my part, when I became aware of this problem I started rigorously monitoring may 12V battery. Initially it was reading 11.7V! I charged it back to full and now I take a careful, precise reading every day at the same time. I find that with my car inactive, locked and unused and with both sets of keys stored 5m away inside a faraday box the car loses 0.3V every 24 hours. This may not sound like much but is in fact an enormous depletion and means the battery goes from full capacity to 25% capacity in 3 days.

My car is booked into the dealer on Nov 10th for this to be investigated. Hopefully VW will issue a software update soon as there are a lot of people suffering from this and many cars have died unexpectedly and had to be recovered. In the meantime my recommendation is to regularly monitor and charge your 12V battery!

I really appreciate the detailed and informative responses.

VW though need to get their act together and both inform owners and get the issue sorted pretty quickly.


A

This video shows an alternate method of monitoring the state of the 12 V battery in the ID3.

I have the same problem with the 12 volt battery. In fact the car is at the dealer now whilst they 'investigate' the problem. I can't believe that VW released this car with such a fault. I expect that the dealer won't be able to do anything until a fix is available from VW. It's a bit rubbish that you buy a £39,000 car and then have to go out and buy a battery charger to keep it going!

When you plug the car in to charge it, it charges the 12 volt battery as well as the main traction battery. Apart from the continual power drain on the 12 volt battery which needs sorting, what also doesn't help is that once the car's main battery is fully charged, it stops charging the 12 volt battery too. So if you leave the car parked up for a few days with a fully charged main traction battery, the only way to stop your car dying is to take it for a drive or buy a battery charger! Pants!

I've learned that many EV models are susceptible to the 12V problem - BEVs such as the Nissan Leaf, plus PHEVs like the Toyota CHR (my mum had this with hers)

It is a shame that VW don't see YET to have learned from the mistakes of other manufacturers, but this is a wider problem and not ONLY an ID.3 issue

Hi Guys.

I was planning on leaving my ID3 at Gatwick Airport for 13 days in December - However, that's all been cancelled with lockdown 2.
I was worried about leaving the car for 13 days without charging. Although I planned to charge it on the way at the Ionity fast charge on the M25.

My question, having read about the 12v battery is - would it be a flat battery on our return.
Has anyone else left there ID3 for a long period ?

thanks

Mine wasn't used for 10 days while waiting for a replacement windscreen to be fitted - though I did do a couple of small charges to the main batteries during that period as I read a post somewhere from a guy who found that doing that would also send some charge to the 12V.

From the number of reports I've read (on multiple Facebook groups and YouTube channels) the 12V issue seems to only affect some cars not all - but who knows...?

A noob question both to ID3 and cars in general - can you monitor the 12v battery from the car’s software or the app - or do you need to meter the battery terminals directly? We’ve had issues with the alarm going off and one of the possible causes (I read) can be a low 12v battery - so I’m putting 2&2 together... wondering if that makes 12!

Thanks for any advice

You need a meter from everything I’ve seen and read.

I did read that the 12V gets a charge while you’re charging the car, but not to leave the charge lead plugged in once charging is complete.

Disconnecting when charging completed is not a very good solution from vw as I charge mine overnight and would need to get up at 4 am Yet another mess up with this car and for all of us who took a chance especially as they are now giving new customers 3500 deposit contribution makes you wonder why we bothered

Where can I check the capacity of the 12v battery please?