Rex not coming on at 6%?

BMW i3 Forum

Help Support BMW i3 Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Deutsch100

Well-known member
Joined
Sep 30, 2019
Messages
201
Hi. I have had my 2020 i3S Rex for 2 days now (love it). When I took delivery on Sunday 9/27/20, the dealer did not have time to charge my car. They delivered it to me with about 35 miles of range.

I was able to make it home on the charge, but I was kind of hoping the Rex would have kicked on. My 2019 i3S Rex would activate when my battery SOC dipped below 7%. My 2020 was still running on battery power at 6%. Is this normal? Thank you.
 
I believe the REx is supposed to start automatically at a nominal 6.5% charge level. However, REx owners have reported it starting at charge levels slightly below and above 6.5%. Had you driven one more block, it probably would have started :D Nevertheless, it's probably worth testing to ensure that it starts at 6.5% ± 1%.
 
Thank you for the reply alohart!

I remember my 2019 i3 would kick on Rex about the millisecond the Battery went below 7%. I was surprised at 6% with the A/C running and it being almost 100F outside, that the Rex did not kick on at 6% in my new 2020.

I have been reading some "horror" stories on this Board where people are complaining that Rex never kicks on and they get stranded :-O #wedonotwantthat ;)
 
I would think an error message would appear on the dash if your REx was INOP, further cautioning you to be prepared to drive on electrons only.
 
While you would want to test that it comes one when it should, to verify that it can turn on, you could force it to run in the emissions test mode once you get the SOC below (I think) 75%, or, if you program the ability to force it on via menu like the rest of the world can do.
 
Thanks for replying BL5 and Jadna!

I do understand that I can force a Rex start with emissions test mode, but I do want to make sure Rex will auto engage in case I am in motion, especially on the highway. I am not too concerned if Rex will turn on by force (as I am under full warranty if a repair is needed), I just want to make sure it will auto engage ;)
 
Nice day today, and very light traffic so I took my new i3 out for a joyride to drain the battery and check on Rex's operation. On my '19 i3S, the REX would come on the second the battery would hit that under 7% SOC.

The battery went down lower than in my '19, but my 2020 Rex fired right up today... automatically, perfectly and seamlessly. Unless it is my imagination....my '20 Rex is much quieter and smoother than my '19. In fact, I did not know it was even running for the most part. LOVE being back to an i3.
 
Back
Top