This is my experience with a 2021 SE built at the end of July 2020, in case newer model years don't do this. I have previously complained about getting wonky battery State Of Charge (SOC) values in A Better Route Planner (ABRP) using a "cheaper" OBDII dongle, that I thought had been resolved with a more expensive, well-regarded dongle. After a while, I started seeing wonky values on occasion with that better dongle. Having taken quite a few road trips now (the only scenario where I actually use the dongle + ABRP), I think the problem actually lies within the software/subsystem of the SE that instruments the battery SOC to the OBDII port. As evidence, I managed to capture these two images from my phone during my last trip: The first image shows that the MINI app and ABRP claim my SE's battery is at 81% while the DCFC I'm plugged into shows the correct SOC of 54%. The second image shows the MINI app getting confused shortly after plugging in, showing the correct SOC when I plugged in, yet somehow jumping instantly to a much higher SOC. I haven't been able to figure out what triggers this confusion, but it appears to be some combination of having an OBDII dongle plugged in and using DC fast chargers. Sometimes, unplugging the dongle for an hour or two helps, but not always. An overnight Level 2 charge always seems to help clear things up. For what it's worth, the instrument cluster has ALWAYS shown the correct state of charge, as have all the DCFC dispensers I have plugged into. I think the Battery Management System (BMS) is fine. This problem seems to only affect the "extra" reporting done via OBDII (which I assume feeds the info sent to the app). At least now I can stop blaming ABRP and/or the OBDII dongle running off into the weeds. They seem to be victims of "garbage in, garbage out".
Thanks for posting your experience. The "check engine" light just came on on my son's car, which has me considering buying a dongle to read the code(s) causing it, then using it in my SE. I don't really have any specific plans for the latter, though, and if the data isn't always reliable, one less reason to spend the money.
I've used the ELM dongle and Car Scanner Pro on several f&f's cars over the past couple of years (even though I haven't BimmerCoded mine since August, 2022). It's more than paid for itself.
Yeah, I'm definitely not saying "don't bother with an OBDII dongle". I'm just saying that if you leave it in all the time, you might start to get some incorrect battery SOC readings in ABRP. Or, at least I do.
