Does this sound like I need a new 12v battery?

[imchrisd]

Here's what happened to my 2016 REx...

A few days ago, I was programming the home link on the mirror and I had to turn the car off and on several times. When I pulled it into the garage, the check engine light was on. I drove it for a couple days because I wasn't using the gas engine and last night I plugged it into charge at about 55%. This morning I came out and it's completely dead. Nothing turns on and no lights come on when I plug in the charger.

Sound like time for a new battery or something more serious???

Thanks in advance, Chris

 

[imchrisd]

Oh yeah, I never got an indication about the battery discharging.

 

[alohart]

You almost certainly need a new 12 V battery, especially if the current battery is the original. If you have a 12 V battery charger, disconnect the high-voltage disconnect to the right of the frunk box, attach the charger to the battery, and see whether it will hold a charge.

 

[imchrisd]

Does anybody know where I can get a battery in Arizona? :roll: :?:

 

[alohart]

Does anybody know where I can get a battery in Arizona? :roll: :?:

A BMW dealer should have one or could get one pretty quickly. Or you could order one from Remy Battery which others have reported ship pretty quickly.

 

[frictioncircle]

Just to add on... the battery you want to order, imchrisd, is an AUX18L:

https://remybattery.com/start-stop-aux18l-auxiliary-battery.html

EDIT: Realized that I've just posted the same link as alohart.

 

[frictioncircle]

There is a BMW Service Information Bulletin for replacing the 12V battery:

"SI B61 21 010 Remove and install (replace) 12V AUX vehicle battery"

You might be able to find it with a bit of searching but BMW has recently cracked down on sites that republish their technical documents, unfortunately.

There are a number of videos on YouTube that show how to do this. Having an app like BimmerLink will allow you to inform your i3 that it has a new 12V battery. The process is called "battery registration" and is more important for ICE BMWs versus the i3 but check it out in your searching.

 

[imchrisd]

Thank you to everyone who replied. I did replace the battery and it solved the issue. I was able to get one at the Stealer for $180 which is about the same price as the mail order one with shipping.

I reset all of the many errors with Bimmerlink but still have a Check Engine light with these errors:

09 Range extender motor electronics
1 error
117000: Fuel tank pressure / temperature sensor circuit: Malfunction or open circuit

1D Hybrid pressure refuelling electronic control unit
1 error
D04C1E: Sub-bus failed / tank pressure sensor does not respond

So goes my next project...

 

[alohart]

09 Range extender motor electronics
1 error
117000: Fuel tank pressure / temperature sensor circuit: Malfunction or open circuit

1D Hybrid pressure refuelling electronic control unit
1 error
D04C1E: Sub-bus failed / tank pressure sensor does not respond

I don't have a REx, but I believe I recall reading that BMW has extended the warranty on the fuel tank pressure sensor which has failed for many REx owners. If true, a BMW dealer would replace it at no cost. Hopefully, a REx owner will clarify and correct.