My i3 is Dead

[Shrink13]

Sorry to hear about all of your troubles and the expense. In the US, we can turn the GPS on and off in one of the menus, so maybe no additional trip to the dealer will be required.

Good luck.

 

[Fisher99]

It’s been an experience....

First I replaced the battery £80
Flatbed to get it to the dealer £120
Once at the dealer:
- £48 to code the battery
- £300 to diagnose
- £67 to replace an actuator for fuel filler cap
- £60 to test that

The KLE was replaced at the same time - I think under recall as it was free

On the way home it started to show a brake issue. Turns out the vacuum sensor had gone (its right next to the fuel filler actuator but apparently it was just a coincidence...) - that was another £280.

Now it’s home I find that the GPS has been switched off so third visit to the dealer.

The saga continues...

I don't see anything on that list that would have fixed the problem (other than the new battery, of course). My guess is that during their "diagnosis" the issues cleared, and possibly would have anyway over time. Mine did basically the same thing but eventually cleared itself on its own.

 

[deolsunny533]

I would love to do the 40Ah retrofit if it was possible to code/register the larger battery. My late production 2015 BEV is probably living on borrowed time with the original 12V battery at this point, and I plan to change it before winter as a maintenance item.....

 

[Fisher99]

I would love to do the 40Ah retrofit if it was possible to code/register the larger battery. My late production 2015 BEV is probably living on borrowed time with the original 12V battery at this point, and I plan to change it before winter as a maintenance item.....

Yes, with a 5 year old 12v battery, I'd agree that you are probably due. And based upon my experience when my 12v died, I would strongly suggest that you replace it before it fails. The i3 gets VERY unhappy when the 12v battery dies! Be sure to disconnect the main traction battery first, as a precaution.

For what it's worth, and I don't know that this is always the case, but a clue that I should have paid attention to is that in the 2 or 3 weeks prior to the 12v dying, I noticed that the range would decrease while the car sat in my garage over night. Must have been using juice from the traction battery to try to keep the 12v battery charged. But with 5 years on the battery, I wouldn't wait. I'm planning on replacing mine at 4 years.

 

[Awesomei3]

Thank you all for your advice - finally done today as the dealer restored the GPS feature on the iDrive (remarkably for free).

Now due a service in November - fingers crossed that we only needs one visit not three.

In the meantime I’ll get back to enjoying my awesome little car!

 

[paradiddle]

Thanks to all of you on this thread. My 12 Volt battery died this week - and I used all of your advice to get back up and running.

I couldn't believe the extent of the "brick factor" that I experienced once the 12V battery had given up.

Charge door locked closed, rear & front hatch locked closed, remote unresponsive...then I discovered the manual wire-loop pull to open the hood. Once I had the hood open, I was able to put the 12V battery on a charger which allowed me to power up the car's systems, which allowed me to get car in-gear and drive it to my BMW dealer to have a new battery installed, and registered.

 

[oldman42]

Thanks to all of you on this thread. My 12 Volt battery died this week - and I used all of your advice to get back up and running.

I couldn't believe the extent of the "brick factor" that I experienced once the 12V battery had given up.

Charge door locked closed, rear & front hatch locked closed, remote unresponsive...then I discovered the manual wire-loop pull to open the hood. Once I had the hood open, I was able to put the 12V battery on a charger which allowed me to power up the car's systems, which allowed me to get car in-gear and drive it to my BMW dealer to have a new battery installed, and registered.

What did you use to charge the 12V?

 

[lesbi3]

BimmerLink app will allow you to register the new battery. It’s from the BimmerCode developer.

 

[alohart]

My 12 Volt battery died this week - and I used all of your advice to get back up and running.

Did you verify that your 12 V battery had actually failed and wasn't merely discharged? The symptoms and warning message are the same. I suspect that some perfectly good batteries are being replaced unnecessarily.

On our 2014 i3 with its original battery, the warning message indicating the 12 V battery's low charge level was displayed a month or so ago. I have a replacement battery ready to be installed after I charge it fully, but instead, I charged the original 12 V battery with a standard battery charger. The battery's charge level was quite low, probably because I have been driving our i3 only about 100 miles per month during the pandemic which is apparently insufficient to maintain its charge level.

 

[Fisher99]

Art: I'm possibly operating under an incorrect assumption but I thought that the 12v battery was charged by the main traction battery? And that this would take place pretty much constantly and not just when driving the car? My reason for this assumption is that for a week or so prior to my 12v battery dying I noticed that the main traction battery would lose a few percentages of charge when sitting overnight. Something that it never did before and stopped doing after I replaced the 12v battery. I took that to mean that the main traction battery was trying to maintain charge in the 12v battery while the car sat in my driveway overnight.

 

[alohart]

Art: I'm possibly operating under an incorrect assumption but I thought that the 12v battery was charged by the main traction battery?

That is correct via the DC-DC converter whose input is the voltage of the high-voltage battery pack and whose output is ~14.3 V to power the 12 V circuit including charging the 12 V battery.

And that this would take place pretty much constantly and not just when driving the car?

The 12 V battery will be charged if needed only when the DC-DC converter is on. The DC-DC converter is on only when the high-voltage system is on. The high-voltage system is on when driving, when actively charging (i.e., not after the battery pack is full), when preconditioning, and after unlocking or opening a door, the frunk, or the hatch. The high-voltage system will remain on for ~30 minutes after an event that has turned it on ends.

I can see when the DC-DC converter is charging the 12 V battery because I always have a 12 V voltmeter in the auxiliary power port below the center of the dashboard. However, after the auxiliary power port shuts down automatically, the voltmeter is no longer powered, so I would not be able to see when the DC-DC converter is charging the 12 V battery. However, I've not read of periodic 12 V battery charging events occurring while an i3 is parked and not charging or preconditioning by anyone who has installed a 12 V battery monitor.

My reason for this assumption is that for a week or so prior to my 12v battery dying I noticed that the main traction battery would lose a few percentages of charge when sitting overnight. Something that it never did before and stopped doing after I replaced the 12v battery. I took that to mean that the main traction battery was trying to maintain charge in the 12v battery while the car sat in my driveway overnight.

I've never read a detailed description of an i3's 12 V battery charging protocol, so I'm guessing how it works based on my observations. Several i3 owners have reported their 12 V battery discharging while parked for several weeks which suggests that the 12 V battery isn't being charged while an i3 is parked. However, one i3 owner has reported that his 12 V battery still had sufficient charge to start his i3 after it had been parked for 2 years! It's difficult to explain that unless the 12 V battery was being maintained automatically.

 

[Steve999]

I also have a voltage monitor installed in the auxiliary port under the dash, and I have noticed (with the car sitting for multiple days this winter) if I just open the rear hatch usually the interior lights and ports will turn on only for several minutes ( allowing me to check the 12V battery status). This normally doesn't trigger the contactor (I can hear the 'click') and turn on the DC-DC converter. However, two times now I could see the voltage drift from ~12.4 volts down to just under 12.0 volts under load, and then the contactor would trigger and start charging the battery at ~14.8V. I have not seen this happen on it's own without some external event ( like opening the trunk, or possibly an unlocking event (haven't verified this)). I have been driving it more recently, & haven't seen the voltages drop below 12.6V since (original battery) supporting Alohart's view that short driving stints may not be enough to recharge the battery completely. Preventative battery replacement this summer may be a good idea anyways for peace of mind(?) 12V battery SOH was 50% as of last summer using cheap meter purchased on Amazon.

 

[alohart]

I also have a voltage monitor installed in the auxiliary port under the dash, and I have noticed (with the car sitting for multiple days this winter) if I just open the rear hatch usually the interior lights and ports will turn on only for several minutes ( allowing me to check the 12V battery status). This normally doesn't trigger the contactor (I can hear the 'click') and turn on the DC-DC converter. However, two times now I could see the voltage drift from ~12.4 volts down to just under 12.0 volts under load, and then the contactor would trigger and start charging the battery at ~14.8V.

This mirrors my experience except that my voltmeter is displaying slightly lower voltages. It appears that if the voltage of the 12 V battery is high enough, the DC-DC converter won't turn on when I unlock the doors, the frunk, or the hatch, so the 12 V system voltage remains that of the 12 V battery. This isn't my usual situation, probably because my 12 V battery's voltage is lower than it should be due to my infrequent driving. Immediately upon unlocking the doors, the voltage usually begins dropping to as low as 11.8 V before the DC-DC converter turns on within ~5 seconds which increases the 12 V system voltage to ~14.3 V. I take advantage of this behavior to unlock and then lock the doors remotely a couple of times each week using the BMW Connected app in hopes that the resulting 30 minutes of 12 V battery charging will prevent the 12 V battery from discharging too much.

12V battery SOH was 50% as of last summer using cheap meter purchased on Amazon.

These cheap meters are probably only measuring the battery's voltage which isn't a good indication of state of health. Low voltage could be due to a perfectly healthy battery being discharged from not enough driving. A load test is probably the only way to really assess the state of health.

 

[eNate]

A consideration is the Aux 18L 12v battery is rated at 20Ah, or about 0.24 kWh. So with an original model i3 outfitted with a 22 kWh battery, the 12v battery represents 1% of the traction battery's capacity. I'm guessing it would be pretty hard to not notice the 12v battery is dead beyond dead if it was sucking a noticeable percentage off the main battery's state of charge.