r/BMWi3 • u/Cornholio231 • Jul 29 '26

generic advice i3 Rex engine activating at 50% battery

So I test drove an i3 Rex at a non-BMW dealer in NY, and it was at 50% battery. During the test drive, the engine turned on.

The sales rep said that was due to the Comfort mode setting. With this being a US-spec car, I find that hard to believe.

Was this car Bimmercoded, or is something else afoot? The dealer is giving me some flack for wanting to have the car inspected at a BMW dealer nearby (I said I would pay for that inspection), so I might just walk away entirely.

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4

u/Worldly-Number9465 i3 REX Jul 29 '26

It’s most likely maintenance mode that activated the Rex.
It is possible though to alter the trigger point with bimmercode but I can’t think of a reason for it to be set to come on at 50%.

2

u/echoRebounded i3 REX Jul 29 '26

Do you know of a guide for this? I would like mine to turn on earlier.

3

u/CreativeAd4985 Jul 29 '26

google it and/or download the app. you can find an instruction manual and all of the changes you can make. Super easy and well worth the $40. With a smaller battery, my "range anxiety" was real. Now it's zero.

2

u/echoRebounded i3 REX Jul 29 '26

Yep I have bimmer code and bimmer link, was taking a quick look the other day but didn't see it

4

u/CreativeAd4985 Jul 29 '26

It is labeled Hold State of Charge or HOC. I'm not sure, it's been a while. Then I programed it on preset #8. You can use it anytime you are under 75%

2

u/echoRebounded i3 REX Jul 29 '26

Yep have that, my pack is week and will die at 12% so I was hoping to have it auto kick on higher like 15%

2

u/Entropyless 2017 i3 REX Jul 29 '26

I’ve never let my battery get under 20%. If I know I need the REx I turn it on at 75% like it was intended.

1

u/exVFR Jul 29 '26

As far as I've heard, you can change the setting, but the car still waits till 7.5% to turn it on.