alohart
Posts: 1431
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Mon Jul 09, 2018 3:22 pm

sogorman wrote:The original usable capacity of the i3 battery as stated from BMW is 18.8 kWh of the actual 22 kWh. This indicates that there is 1.2kWh (5.45%) of SOC that is reserved by the BMS.

You might have meant to write 21.6 kWh - 18.8 kWh = 2.8 kWh, or ~13% of the total capacity reserved by the BMS.

sogorman wrote:Some of that is for anti bricking on the low end which would mean that "fully charged" is to your point not 100% SOC but closer to 95%.

Agreed.
Aloha,
Art

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

sogorman
Posts: 9
Joined: Sat Jul 07, 2018 1:00 pm

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Mon Sep 03, 2018 10:01 am

Just a quick update, my Max Kappa reading is now down to 14.7kWh.

On a side note does anyone know of someone who has had their battery replaced with BMW?

EVMan
Posts: 245
Joined: Sat Feb 25, 2017 4:31 pm
Location: USA, CA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Mon Sep 03, 2018 6:22 pm

The one think i am noticed , the rate of deterioration after 2 years and 20K miles seams to be accelerating for me

I have 2 , and weather is relatively stable , but the older car shows month by month reduction.
First 1.3 years , i did not see any significant reduction.
2016 22KWH Rex ( Lease to Return ) ~ Model 3 Dual Motor, Long Range ( Wait-listed )
2017 33KWH Rex
Solar ToU Plan

Oleksiy
Posts: 45
Joined: Fri Mar 23, 2018 4:30 am
Location: Kyiv, Ukraine

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Mon Sep 03, 2018 10:34 pm

@sogorman, @EVMan, do you track the temperature of the pack as you take readings of Batt.Kapa? It's interesting whether the TMS is that efficient as it's claimed to be.

The max I saw was 86F, but the highest ambient temperature recorded was 88F, we had a moderate summer this year. I wonder how the pack behaves under more extreme conditions of, say, Phoenix.

Oleksiy
Posts: 45
Joined: Fri Mar 23, 2018 4:30 am
Location: Kyiv, Ukraine

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 4:20 am

People on German forum discuss some pack re-initializing procedure conducted by local BMW repair shops. They claim that after this procedure Batt.Kapa goes up 1-2 kWh with corresponding increase in available range.
https://www.goingelectric.de/forum/bmw- ... 21457.html

rtanov
Posts: 148
Joined: Mon Oct 20, 2014 10:55 am
Location: Cincinnati, OH, USA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 8:46 am

@sogorman, why don't you take it to the dealer and claim the excessive degradation warranty. They have a financial incentive to do the replacement and charge BMW for it if it is excessive and BMW agrees. I don't see any disadvantage in doing so. Worst case they will reject your claim but you would have their official measurement of where the battery stands right now.
2014 BMW i3 REx
2014 BMW i3 BEV - retired

EVMan
Posts: 245
Joined: Sat Feb 25, 2017 4:31 pm
Location: USA, CA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 10:12 am

rtanov wrote:@sogorman, why don't you take it to the dealer and claim the excessive degradation warranty. They have a financial incentive to do the replacement and charge BMW for it if it is excessive and BMW agrees. I don't see any disadvantage in doing so. Worst case they will reject your claim but you would have their official measurement of where the battery stands right now.


I guess you need to hit 30% , to get warranty
2016 22KWH Rex ( Lease to Return ) ~ Model 3 Dual Motor, Long Range ( Wait-listed )
2017 33KWH Rex
Solar ToU Plan

EVMan
Posts: 245
Joined: Sat Feb 25, 2017 4:31 pm
Location: USA, CA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 10:18 am

Oleksiy wrote:People on German forum discuss some pack re-initializing procedure conducted by local BMW repair shops. They claim that after this procedure Batt.Kapa goes up 1-2 kWh with corresponding increase in available range.
https://www.goingelectric.de/forum/bmw- ... 21457.html


While the pack re-initializing will have an immediate effect on readings, sooner or later it will catch up on the actual status of the battery.
Cycle complete battery from full to 0 , will also kind of re-initialize.
2016 22KWH Rex ( Lease to Return ) ~ Model 3 Dual Motor, Long Range ( Wait-listed )
2017 33KWH Rex
Solar ToU Plan

EVMan
Posts: 245
Joined: Sat Feb 25, 2017 4:31 pm
Location: USA, CA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 10:20 am

Oleksiy wrote:@sogorman, @EVMan, do you track the temperature of the pack as you take readings of Batt.Kapa? It's interesting whether the TMS is that efficient as it's claimed to be.

The max I saw was 86F, but the highest ambient temperature recorded was 88F, we had a moderate summer this year. I wonder how the pack behaves under more extreme conditions of, say, Phoenix.


How do you take this temperature reading of the pack ?
Higher the temp, the battery capacity increases, but will effect life negatively.
88 looks reasonable.
2016 22KWH Rex ( Lease to Return ) ~ Model 3 Dual Motor, Long Range ( Wait-listed )
2017 33KWH Rex
Solar ToU Plan

rtanov
Posts: 148
Joined: Mon Oct 20, 2014 10:55 am
Location: Cincinnati, OH, USA

Re: 2015 i3 Battery Degradation (20% after 30k miles)

Tue Sep 04, 2018 11:18 am

EVMan wrote:
rtanov wrote:@sogorman, why don't you take it to the dealer and claim the excessive degradation warranty. They have a financial incentive to do the replacement and charge BMW for it if it is excessive and BMW agrees. I don't see any disadvantage in doing so. Worst case they will reject your claim but you would have their official measurement of where the battery stands right now.


I guess you need to hit 30% , to get warranty


The last measurement in the OP's doc shows >30% degradation - the 3 measurements there vary significantly, so it depends on how the dealer measures it. Also, even if not quite 30% but close they might be willing to work with him to get the warranty approval by BMW as they will make money on the replacement work. If I were in OP's position I'd go for it - it would give me one extra data point on the battery degradation state and help plan how to proceed in maintaining or stressing the battery in the future.
2014 BMW i3 REx
2014 BMW i3 BEV - retired

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