bwilson4web
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Re: BMW i3 auxiliary battery sizes

Fri Mar 23, 2018 10:22 am

I suspect the post-drive fans and cooling loops are driven by the 12V battery. This would wear down the 12V battery faster than if these post-drive loads were not there.

Bob Wilson
20k/27k mi 2014 BMW i3-REx
10k/10k mi 2017 Prius Prime

alohart
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Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: BMW i3 auxiliary battery sizes

Fri Mar 23, 2018 4:17 pm

bwilson4web wrote:I suspect the post-drive fans and cooling loops are driven by the 12V battery.

The A/C compressor is powered by a high-voltage motor. I'm not sure about the front heat exchanger fan motor.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

alohart
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Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: BMW i3 auxiliary battery sizes

Tue Jan 08, 2019 3:16 pm

Apparently the OEM i3 12 V AGM battery is made by East Penn Manufacturing under the Deka brand. Its model number is AUX18L. Local dealers can be found here for those of you interested in replacing the battery yourselves. I have just sent my local dealer an email message requesting availability and price. If this dealer can sell a battery to me, I would have another source than my BMW dealer, hopefully at a lower price.

Now I need to figure out the best way to register the battery. The Carly tools apparently require a Windows operating system to install BMW software. I don't do Windows, so Carly is not an option for me. An independent BMW mechanic would likely charge less than my BMW dealer, but I would like to be able to register the battery myself. What's the least expensive tool that could register a new battery?
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

jadnashuanh
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Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: BMW i3 auxiliary battery sizes

Tue Jan 08, 2019 4:20 pm

You should be able to do it with the Bimmercode app, assuming you have iOS devices. The license for the app and the OBD device to talk to the car should easily be available for about $50. Some other BMW driver near you might do it for you for free.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

alohart
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Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: BMW i3 auxiliary battery sizes

Tue Jan 08, 2019 11:20 pm

jadnashuanh wrote:You should be able to do it with the Bimmercode app, assuming you have iOS devices.

I have BimmerCode. Unfortunately, it is currently unable to register a new battery.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

tman66
Posts: 45
Joined: Tue Oct 02, 2018 12:10 pm
Location: Guelph, ON, Canada

Re: BMW i3 auxiliary battery sizes

Wed Jan 09, 2019 7:36 am

Very interesting topic and hopefully my question is not too far off;

I'm going on vacation from Saturday to Saturday and was thinking of leaving the i3 plugged into the standard 110v wall charger while I'm gone. I have a 6:00am climatize schedule set for weekdays as well. The i3 will be in the garage with expected minus (Celcius) temps next week.

Would that be ok or is there a better way ?
2014 i3 BEV | 2011 328xi Wagon

alohart
Posts: 1494
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: BMW i3 auxiliary battery sizes

Wed Jan 09, 2019 2:26 pm

tman66 wrote:I'm going on vacation from Saturday to Saturday and was thinking of leaving the i3 plugged into the standard 110v wall charger while I'm gone. I have a 6:00am climatize schedule set for weekdays as well. The i3 will be in the garage with expected minus (Celcius) temps next week.

Would that be ok or is there a better way ?

Just park it with climatization off, the battery pack charge level ~50%, and the EVSE not plugged in. The 12 V battery won't discharge enough in 7 days to cause problems, the Li-ion battery pack won't discharge enough to be noticeable, and you won't waste energy climatizing a car that won't be driven.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

jadnashuanh
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Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: BMW i3 auxiliary battery sizes

Wed Jan 09, 2019 6:47 pm

The data points can probably be accessed in expert mode, but I'm not positive. They were for my ICE.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

tman66
Posts: 45
Joined: Tue Oct 02, 2018 12:10 pm
Location: Guelph, ON, Canada

Re: BMW i3 auxiliary battery sizes

Wed Jan 09, 2019 7:13 pm

alohart wrote:
tman66 wrote:I'm going on vacation from Saturday to Saturday and was thinking of leaving the i3 plugged into the standard 110v wall charger while I'm gone. I have a 6:00am climatize schedule set for weekdays as well. The i3 will be in the garage with expected minus (Celcius) temps next week.

Would that be ok or is there a better way ?

Just park it with climatization off, the battery pack charge level ~50%, and the EVSE not plugged in. The 12 V battery won't discharge enough in 7 days to cause problems, the Li-ion battery pack won't discharge enough to be noticeable, and you won't waste energy climatizing a car that won't be driven.


Hey Art, thanks for the suggestion. It makes more sense than what I was thinking. Newbie EV owner paranoia I guess.

Is there any particular reason why the battery should be at ~50% and not let’s say 100%?
2014 i3 BEV | 2011 328xi Wagon

jadnashuanh
Posts: 4252
Joined: Thu May 22, 2014 2:07 pm
Location: Nashua, NH USA

Re: BMW i3 auxiliary battery sizes

Wed Jan 09, 2019 9:39 pm

The car won't turn on the EVSE until the battery level drops. There is no possibility that power will be applied continuously and potentially damaging the batteries. BMW suggests to leave it plugged in. The level must drop a few percent after charging before the car will turn the EVSE back on again. The system is pretty smart in that regard.

Long-term, the biggest issue is the 12vdc battery getting discharged and, if it's really cold, potentially freezing. That can't happen if it's charged or connected to an EVSE. An i3 isn't your laptop of cellphone...the battery management and EVSE combined are a lot smarter.
Jim DeBruycker
2011 535i x-drive GT, 2014 i3 BEV

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