12v battery life

Faults and Technical chat for the Volkswagen ID.3
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Rockonron
Posts: 14
Joined: Thu Nov 05, 2020 8:29 am

Post by Rockonron »

Just wondering what other peoples experiences are with the 12v battery, I am been vigilant checking it every week, and every week I seem to need to charge it up as it is almost completely flat.

I am driving the car everyday, and I know ev have issues with 12v but surely the battery can hold a charge for longer than a day.

I suspect the 12v is bad and will look at getting it replaced. Curious about others experiences.

Deleted User 192

Post by Deleted User 192 »

Mine went once just before Christmas, the AA guy (via VW) brought it back to life and it’s been fine since.

I don’t monitor it, and don’t have a charger for it.

There was an update in the 2.0 / 0783 software which had the car monitor it, and use power from the main battery pack to charge it if needed.

If I were you I would be reporting it to your dealer.
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kaiz
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Location: Estonia

Post by kaiz »

Have't been problem with 0783 yet. ;)
Life Pro Performance, Manganese gray, Heat pump, Tow bar, 0792 / 2.1.
sb96
Posts: 13
Joined: Sat Jan 02, 2021 10:16 am

Post by sb96 »

My girlfriends ID.3 died due to 12v battery, contacted VW and they said they needed to take it to mechanics.

Said and done, we got a new rental car, an ID3, almost identical to the one she had.

The day after we got the ID3 rental it died with the same issue. Now they gave her a Passat instead :)

Buying an ID3 has really been something. I've had more issues with this car than my last 5 cars combined... And our issues just keep growing, will be fun to see what our car does next!
Sindidziwa
Posts: 84
Joined: Wed Oct 07, 2020 4:06 pm

Post by Sindidziwa »

So... ID.3 upgraded to 2.1 on 19 March - today I have a battery warning saying “drive car to charge” - never happened before, even if the car was quarantined for a few days. So I went for a 40 minute drive - no change. So I connected a battery charger which says 12.6V. Is this happening in to anyone else? Could be the battery (I’ve done about 500 miles in the last week though) or software or physical fault?? [Hair tearing out emoticon]
CarterHounslow
Posts: 216
Joined: Sun Mar 28, 2021 1:01 pm

Post by CarterHounslow »

Rockonron wrote: Fri Feb 26, 2021 7:58 am Just wondering what other peoples experiences are with the 12v battery, I am been vigilant checking it every week, and every week I seem to need to charge it up as it is almost completely flat.

I am driving the car everyday, and I know ev have issues with 12v but surely the battery can hold a charge for longer than a day.

I suspect the 12v is bad and will look at getting it replaced. Curious about others experiences.
Out of interest, how are you checking it? Are you putting a meter on jt?
thefordprefect
Posts: 10
Joined: Fri Feb 05, 2021 2:59 pm

Post by thefordprefect »

I posted this elsewhere on this BB
Had to call the AA/VW out to a totally dead vehicle sitting on drive for 1.5 days unused.

I measured a voltage of 2.94 volts on the 12 volt battery whilst in our drive. To allow the battery to fall to this level is never advised – as an electronic design engineer, I cannot conceive how there was not a low voltage shut down in the discharge path electronics long before this voltage was reached!:

From - Battery 101 Three Things Need Know Lead Acid Batteries | Northeast Battery Blog
“This is a hard and fast NO. By fully discharging your lead acid battery, or even discharging it below 80% of its rated capacity, you could damage the battery.
The belief that a battery needed to be fully discharged before recharging goes back to the memory effect issue. (See question 1.) Since that is no longer an issue (and never was an issue with lead acid batteries) there is not a need to fully discharge.
By discharging a lead acid battery to below the manufacturer’s stated end of life discharge voltage you are allowing the polarity of some of the weaker cells to become reversed. This causes permanent damage to those cells and prevents the battery from ever being recharged.”

The AA engineer who took the vehicle to dealer (I did not want to drive with errors on brakes, steering and 6 other things) a distance of 10 miles informed us that the battery had not recharged during the trip – still read below 12 volts, This may be because the battery charge circuit was non functional or the battery had been damaged by over discharge.

Beware early death of 12 volt battery if the voltage has fallen below recommended minimum!

I believe that symptoms of a damaged battery are lowered capacity and lowered voltage. (If cells are dead as suggested in the quote then you lose 2v for each dead cell)
Sindidziwa
Posts: 84
Joined: Wed Oct 07, 2020 4:06 pm

Post by Sindidziwa »

After getting my car back from the dealer with no reports of any errors and the question "did you leave the ignition on?" we then took a trip to Surrey - 80 miles, left the car for three days and then drove back. This morning I get the 'Low battery drive the car to charge' error - same as last time. I suspect I will have the dead battery warning tomorrow. The battery is obviously not charging properly or is discharging at a high rate...
f080421
Posts: 7
Joined: Tue Aug 10, 2021 6:19 am

Post by f080421 »

Sindidziwa wrote: Fri Apr 09, 2021 3:25 pm So... ID.3 upgraded to 2.1 on 19 March - today I have a battery warning saying “drive car to charge” - never happened before, even if the car was quarantined for a few days. So I went for a 40 minute drive - no change. So I connected a battery charger which says 12.6V. Is this happening in to anyone else? Could be the battery (I’ve done about 500 miles in the last week though) or software or physical fault?? [Hair tearing out emoticon]
Care to tell how this story ended? I'm now having "drive car to charge" situation :roll:
Sindidziwa
Posts: 84
Joined: Wed Oct 07, 2020 4:06 pm

Post by Sindidziwa »

@f080421 In the end I got a replacement transformer? that charges the 12V battery from the main battery and they also replaced the 12V battery as that then showed a fault. I haven't had any problem since then :shock: i wonder whether I will get another replacement 12V battery when 2.4 etc is rolled out next year.
roadhawk
Posts: 105
Joined: Sat Dec 26, 2020 7:37 pm

Post by roadhawk »

My 12v battery failed in the summer and was replaced by the dealer. At that point I had had the car for 9 months. Iy started with the 12v low battery warning, eventually a 12v supply fault which stayed on permanently although the car was driveable. The car ended up drawing from the HV battery when left for a week, draining from 44% to 3%. It would run through up to 9 errors on startup sometimes.
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