Battery Diagnostics

[Davidfromdigswell]

My i3 is now about 5 years old and is currently at the dealership for a service. I asked them if they were able to run any diagnostics to let me know how well the battery pack is performing and if I am getting close to the 70% degradation figure which is when I believe the warranty would kick in. I was told that they have run checks and are only able to confirm that the battery is OK and is charging as expected. I believe my range now is less than it was 5 years ago but not hugely so. Is this data available?

 

[gt1]

Did they tell you the test procedure or gave any numbers besides the "OK"?

 

[Tacfoto]

Here is an article with some infor (toward the bottom) about how to get the car to give you some diagnostic info on the battery:
https://www.bmwblog.com/2017/04/24/bmw-i3-long-term-battery-capacity-report-better-expected/

 

[Tacfoto]

Here is another with better instructions: https://bmwi3owner.com/2016/01/secrets/

 

[Oleksiy]

You could consider installing ISTA+ software and connecting it to your car via OBD2 cable. This one provides a battery snapshot where you could check the cell balancing condition, and the floor and cap threshold the BMS uses for battery charging (usually 8% of the capacity is reserved as unused at the bottom, and 6% at the top). This same piece of software provides for a rigorous diagnostics procedure as well. In this case the car is connected to a charger and then discharged using heaters down to zero for several hours with windows open.

Please refer to this link https://okedv.dyndns.org/wbb/blog/index.php?entry/81-i3-battery-reinit/, this thread https://www.goingelectric.de/forum/bmw-i3-batterie-reichweite/bmw-i3-ploetzlichmit-18-5-kwh-kapazitaet-t21752-520.html#p833738, and this link as well https://okedv.dyndns.org/wbb/blog/index.php?entry/86-bmw-i-series-hochvolt-batterie-spannungen-auslesen/. I don't read German, but google translation into English seems fair.

 

[gt1]

Strange, but ISTA+ doesn't show the battery state of health. I expected more from the Germans with their love of numbers. I have a Chrysler PHEV, and the breadth of data available from the battery is amazing.

 

[Oleksiy]

Is it possible they did it for a reason? Answer customer requests in a binary manner (OK or not OK)is so much more convenient :roll:

 

[gt1]

Still strange. However the discharge test is probably the most accurate way to determine the actual capacity.

BTW, your links took me to a rabbit hole pf trying to integrate Connected Drive and OpenHAB. No luck so far

 

[Oleksiy]

I checked the links, they work on my side.

 

[gt1]

The developer of the openHAB script updated it to work with the US servers, and I got it running. The script can retrieve some data not available in the app, including socMax, which appears to be the same as the Battery Max Kapa. I want to figure how to chart this data to monitor the battery condition over time. Maybe I can even figure out how to integrate openEVSE and automatically limit the charge to a preset level...

 

[Oleksiy]

Oh, I got it now, I didn't understand your first message. Yes, seems like all owners in Germany have this in-app SocMax indicator, very convenient. It's great you can now run it as well.

I didn't check how to do it since BMW won't support ConnectedDrive in Ukraine, so the app won't work either.

 

[gt1]

It sucks. BMW has official representation in Ukraine, they should get ConnectedDrive running. It is just a contract issue. Too bad you can't swap a SIM card and get your car online...

 

[Oleksiy]

Sure they do, for decades. And Ukrainians buy lots of BMWs locally, a very popular brand here. They choose not to proceed for reasons they don’t explain (I’ve contacted the representative office on this matter). Once ConnectedDrive is supported, it would be a matter of TCB unit replacement for me. But I don’t hold my breath