[RichardInCA]

Thanks to MikeElmendorf I got hold of an ENET OBD WiFi adapter and was able to use Bimmerflow to read data about my battery. Pretty cool stuff - seemingly I’m at 96.4% state of health at almost 6,000 miles. Of note - this seems to read “actual” battery capacity available - the one piece of the puzzle that I couldn’t get access to when using efficiency in mi/kWh to determine range. I always had to assume 100% of battery spec was available. Apparently I have 78 kWh available from 79kWh capacity, just a hair below the 81.2 kWh spec.

Anyway, including some screen grabs for you battery egg-heads out there.

[Scrapula]

This is awesome. Can you send me a PM on what you bought and how to hook it up? I want to do this.

[RichardInCA]

Done!

[MikeElmendorf]

Interesting. I’m thinking about checking this out…but afraid I’ll then start to obsess about battery health!

[RichardInCA]

I’m just a geek at heart - I’m really interested in the data to help me understand how my car works. It turns out that on that third screen above you can click on Cell state of health, cell state of charge and cell voltage to see a representation of each cell in the battery - datapalooza.

I’m also kinda interested to see how variable these things are over time - I’ve read others experiences where their battery health fluctuates up and down depending upon temperature etc.

[tsbrown]

Originally Posted by RichardInCA

Thanks to MikeElmendorf I got hold of an ENET OBD WiFi adapter and was able to use Bimmerflow to read data about my battery. Pretty cool stuff - seemingly I’m at 96.4% state of health at almost 6,000 miles. Of note - this seems to read “actual” battery capacity available - the one piece of the puzzle that I couldn’t get access to when using efficiency in mi/kWh to determine range. I always had to assume 100% of battery spec was available. Apparently I have 78 kWh available from 79kWh capacity, just a hair below the 81.2 kWh spec.

Anyway, including some screen grabs for you battery egg-heads out there.

Is this equivalent to iphone battery health? My phone battery health typically drops off dramatically after the first year (below 95%) but I'm not careful about optimum charging. Would the same be expected for i5/550e batteries but probably after 30-40k miles or so?

[RichardInCA]

Originally Posted by tsbrown

Is this equivalent to iphone battery health? My phone battery health typically drops off dramatically after the first year (below 95%) but I'm not careful about optimum charging. Would the same be expected for i5/550e batteries but probably after 30-40k miles or so?

Kinda but I don’t expect battery health to drop off a cliff after a year. This is going to be a great way to track it as there’s no native app in iDrive to give you this information. Range is an elaborate guess-o-meter, efficiency (mi/kWh) is measured, but without knowing remaining battery capacity (which BimmerFlow does) you don’t necessarily know what to do with that other than assume you have 100% of the 81.2kWh to play with.

There’s all sorts of things known about prolonging battery life such as using less DC fast charging, not charging over 80%, charging in smaller increments, storing your car at lower % SOC in hot conditions etc. I think these batteries are pretty robust and that seems to be borne out by users with i4’s and iX’s. It’s all part of the fun of ownership in my book.

[MikeElmendorf]

Well, ok--I don't have to obsess just yet. Checked it out and my battery health is 100%.

Thanks for sharing, Richard.

[tsbrown]

Originally Posted by RichardInCA

Kinda but I don’t expect battery health to drop off a cliff after a year. This is going to be a great way to track it as there’s no native app in iDrive to give you this information. Range is an elaborate guess-o-meter, efficiency (mi/kWh) is measured, but without knowing remaining battery capacity (which BimmerFlow does) you don’t necessarily know what to do with that other than assume you have 100% of the 81.2kWh to play with.

There’s all sorts of things known about prolonging battery life such as using less DC fast charging, not charging over 80%, charging in smaller increments, storing your car at lower % SOC in hot conditions etc. I think these batteries are pretty robust and that seems to be borne out by users with i4’s and iX’s. It’s all part of the fun of ownership in my book.

Guess-o-meter..ha! Or a SWAG (scientific wild ass guess) as we called it in engineering school. Battery management is clearly much more important in an EV than a phone but having knowledge and tools to makes it easier. Surprised that app isn’t built into idrive. Maybe in a future OTA update. Thanks for the info.

[lilstevie]

Originally Posted by RichardInCA

I’m also kinda interested to see how variable these things are over time - I’ve read others experiences where their battery health fluctuates up and down depending upon temperature etc.

I’ve checked mine twice now, with a 2000km road trip between them and it does appear it fluctuates a bit. My first reading was 94.6% at 10,787km and this reading was 95.3% at 12,826km

[tsbrown]

Originally Posted by lilstevie

I’ve checked mine twice now, with a 2000km road trip between them and it does appear it fluctuates a bit. My first reading was 94.6% at 10,787km and this reading was 95.3% at 12,826km

That seems within the margin of error but does anyone with knowledge of these systems know if it’s normal to fluctuate like that? Maybe it’s not important if you track it over a period of time…like weighing yourself, it’s trend vs actual.

[lilstevie]

Originally Posted by tsbrown

That seems within the margin of error but does anyone with knowledge of these systems know if it’s normal to fluctuate like that? Maybe it’s not important if you track it over a period of time…like weighing yourself, it’s trend vs actual.

Most of these systems are using heuristics on a set of inputs to calculate the approximate state of health. They do their best to take them into account but things like cell temperature have non-linear impacts on internal cell resistance which is the main feed for calculating SoH. It’s not an exact science, and is a reasonably accurate estimation, but it’s at the end of the day it’s still just an estimation that most systems have a margin of error around 2-3% for.

It’s definitely something you’ll want to watch a trend for, and normalise that data over time to get a somewhat accurate representation. I think quibbling over 94 or 96% SoH is nothing to worry about, but if it was swinging >5% there might be something that needs to be looked at

[desalvorw]

Originally Posted by Scrapula

This is awesome. Can you send me a PM on what you bought and how to hook it up? I want to do this.

RichardInCA can I get a hold of this too! I’m totally a nerd and geek out a lot about battery health and efficiency. I normally charge most nights I drive and only charge to 65% (when I’m doing daily driving) based on research I had done for better battery health and longevity!

[QandnotU]

RichardInCA do you know if the Bimmerflow app has an Apple Watch companion? The myBMW app counterpart leaves a bit to be desired on the watch.

[RichardInCA]

Originally Posted by desalvorw

RichardInCA can I get a hold of this too! I’m totally a nerd and geek out a lot about battery health and efficiency. I normally charge most nights I drive and only charge to 65% (when I’m doing daily driving) based on research I had done for better battery health and longevity!

There’s no magic here. I went the to bimmerutility website and ordered an ENET adaptor and then downloaded the app and paid $20-$30 to unlock my data. Voila!

[RichardInCA]

Originally Posted by QandnotU

RichardInCA do you know if the Bimmerflow app has an Apple Watch companion? The myBMW app counterpart leaves a bit to be desired on the watch.

No idea I’m afraid. What I am intrigued about is that you can use the app through CarPlay and have it run on your screen - I’m still using the wireless mode on my ENET adaptor that won’t let me use CarPlay simultaneously as I need to use the WiFi connection to ENET to get the data.

[Scrapula]

Originally Posted by QandnotU

RichardInCA do you know if the Bimmerflow app has an Apple Watch companion? The myBMW app counterpart leaves a bit to be desired on the watch.

Testbirds needs beta testers for the MyBMW app on Apple Watch. You should sign up and then you get paid for each bug you write up.

[lilstevie]

Originally Posted by RichardInCA

There’s no magic here. I went the to bimmerutility website and ordered an ENET adaptor and then downloaded the app and paid $20-$30 to unlock my data. Voila!

If you have an older adapter that will work too. My OBDLink MX+ worked fine for it, and I guess unlike the wireless enet adapter works with CarPlay