[-c-]

Originally Posted by afadeev

That is exactly the problem!

Truth be told, this issue shows up in only ~5% of driving situations - driving up long inclines at highway speeds. But if your hill is long enough, and you haven't coded SOC feature back on and used it pro-actively, you can drain the battery down to the 2% level where speed throttling kicks in.

If you don't drive up the mountains, this is a non-issue.

REX does, in fact, charge the batteries up.
Even if you were going up a steep incline and drop the SOC below engagement point, REX will eventually charge it back up to where it kicked in!

Whoever told you that it was a limp-mode back-up was misinformed.
I just want to make that point clear to any other readers who may get turned off from REX (and i3's in general) after reading this thread.

I frequently drive ~145 mile one-way trips.
I know I can't make it w/o REX, so as I approach Poconos, I turn REX on and use up ~75% of the gas tank. Then I turn REX off, and complete the rest of the trip on battery power with ~6% battery charge at the end. Recharge batteries for free at my destination, repeat the routine on the way back. Sometimes, same day.

Zero issues.

Why not?

If you are young, or have kids, you daily routine is anything my consistent.
REX give you ~75 miles of EV range, maybe ~100 if you are super slow and gentle. But if you need to go 150 on a certain day, or double that with ~3.5 hours to recharge in the middle, it will still do the job.

No-one needs an electric car, period.
But it's kind of cool and fun to make one work for your lifestyle. REX made it possible for me to dip my toes into the EV world.

To each his own!

Well, Cali CARB bureaucrats did what all bureaucrats do - pulled rules out of their asses. It's what they do. You can't blame the fish for being wet all the time!

There is no requirement for BMW to follow those B.S. rules and disable "hold SOC" and castrate the gas tank. They did it to max out ZEV credits. You can't blame them for looking after their own bottom line either - it's what BMW NA execs are paid to do.

None of this would be an issue if REX had larger charging capacity.
None of this is an issue any longer if you take 20 minutes to code away BMW CARB hacks.

Common, it's the internet, isn't that why we are all here!?



a

Hey man, sorry had a bad week you probably noticed I was more mad mood than usual.

Otherwise all better now. Was in a bad mood because our x5 blew or so I thought the transfer case which was going to cost me over 5g's and they where pushing for a transmission as well so over 10g's total, Ended up changing the fluid by myself because they would not do it and advised against it and after fluid change all the transmission and transfer case issues went away. Now it drives like new again. Told my wife to tell me when these driving issues come up so we can catch them earlier. Either way I'm in a way better mood. Still hate my dealer and their miss information all the time.

Like you I love the i3 why I bought it vs leased it and look forward to owning it for a very long time. Otherwise lets get back to our regular scheduled program .

[afadeev]

Originally Posted by -c-

Was in a bad mood because our x5 blew or so I thought the transfer case which was going to cost me over 5g's and they where pushing for a transmission as well so over 10g's total, Ended up changing the fluid by myself because they would not do it and advised against it and after fluid change all the transmission and transfer case issues went away. Now it drives like new again. Told my wife to tell me when these driving issues come up so we can catch them earlier. Either way I'm in a way better mood. Still hate my dealer and their miss information all the time.

BMW's sanctioned automatic transmission neglect is just sad.
A few local dealers flat out refused to change tranny fluid in my old E46 and then again Mini Cooper S. I ended up doing both myself, and both improved transmission smoothness and speed of gear changes.

For better of worse, these are not the challenges i3 owners will ever face.
Electronics and charging - yeah, we've got those.

This reminds me - time to get back on the phone with the service department and schedule another visit to fix the newly disabled drive side seat heater.
*sigh*

a

[tommolog]

Originally Posted by afadeev

Larger MY'17 battery just delays the point when REX kick's in. If it still kicks in at 6% of remaining battery charge, the same problem will reoccur. If they raise the engagement threshold to 10+%, then REX weakness will be better hidden, but at the expense of limiting battery's usable capacity.

a

The REx currently turns on at 6.5% SOC which means there is roughly a 1.23 kWh buffer with the current battery pack. Since the new battery holds a little more than 40% more energy, the new buffer would be increased to about 1.8 kWh if BMW kept everything else the same. I don't believe they are going to do that. I expect BMW to hold more energy in reserve in the lower end of the usable capacity, so even if they call it 6.5%, it will be more, probably as much as 10%.

If they do this, it's going to hurt the EPA range rating of the 2017 REx, because there won't be as much energy readily available in pure EV mode. However I expect them to do this to end the issues it has with regards to reduced power. If they do this, the car will have about 2.75 kWh in reserve when the REx turns on, more than double what it currently has. Combine that with tuning the engine to deliver a little more power would eliminate the reduced power issues for just about any circumstance. It won't completely solve the problem, because if someone wants to climb a 20 mile long, 6% grade at 75 MPH there's nothing that's going to solve that with this current car, short of allowing the manual hold mode at 75% SOC.

One way to tell is to take a look at the EPA range ratings for the 2017 BEV and REx cars. Currently the REx penalty is 9 miles of range (72 miles compared to 81 miles per charge for BEV). If the 2017 REx has more than 10 miles less range (EPA rating) then the BEV, then I think it's safe to say they held more energy for the REx low end buffer.

[ky_soldier]

So is there a fix? It happened to me a few weeks ago driving to CVG airport and yes - it's scary and I was cursing like mad. It was a huge deal as I was doing just over 70 in the fast lane and then wham - won't go over like 50mph. Even worse, I was trying to catch a flight and that extra time pissed me off even more. They should offer the ability to code the vehicle to allow owners to do a hold state of charge to whatever percent they feel comfortable with.

[afadeev]

Originally Posted by ky_soldier

So is there a fix? It happened to me a few weeks ago driving to CVG airport and yes - it's scary and I was cursing like mad. It was a huge deal as I was doing just over 70 in the fast lane and then wham - won't go over like 50mph. Even worse, I was trying to catch a flight and that extra time pissed me off even more. They should offer the ability to code the vehicle to allow owners to do a hold state of charge to whatever percent they feel comfortable with.

If you are comfortable coding - yes, and then some (open up the entire 9 liter gas tank, etc, etc).
If not, then no.

a

[congdongdesigner]

: Mad0259: First i heard of this as well. Wonder if anyone else has experienced this or just this one guy?

[Kiwi]

Originally Posted by ky_soldier

So is there a fix? It happened to me a few weeks ago driving to CVG airport and yes - it's scary and I was cursing like mad. It was a huge deal as I was doing just over 70 in the fast lane and then wham - won't go over like 50mph. Even worse, I was trying to catch a flight and that extra time pissed me off even more. They should offer the ability to code the vehicle to allow owners to do a hold state of charge to whatever percent they feel comfortable with.

The world is not ready for just EV's on freeways. I purchased a BMW plugin Hybrid as I want the security of be able to drive to and return from. EV's are very limited and only good as a run around.

I could also say you didn't plan your trip correctly and you should have charged your i3 so this would not happen. Their's no reason what so ever i3 owners do not read their i3 handbook supplied and know the cars limitations. It's only in America cars have all these alarms to wake drivers up to what they should be doing. Now Americans need autonomous cars because alarms are not working so lets stop Americans driving all together.

[ky_soldier]

Originally Posted by Kiwi

The world is not ready for just EV's on freeways. I purchased a BMW plugin Hybrid as I want the security of be able to drive to and return from. EV's are very limited and only good as a run around.

I could also say you didn't plan your trip correctly and you should have charged your i3 so this would not happen. Their's no reason what so ever i3 owners do not read their i3 handbook supplied and know the cars limitations. It's only in America cars have all these alarms to wake drivers up to what they should be doing. Now Americans need autonomous cars because alarms are not working so lets stop Americans driving all together.

It was fully charged. The car says it has a range of 82 miles. It ran dead at like 60 or so. The fact that using it at highway speeds compromises range that much just stinks. It also has a range extender for just such instances. It's about 70 miles from my house to CVG, where they have chargers in the parking garage. Tell me again what else should I have done again??? If the car had the ability to do "hold state of charge" before almost empty like they do in the rest of the world, this could have been avoided.

[ky_soldier]

Originally Posted by congdongdesigner

: Mad0259: First i heard of this as well. Wonder if anyone else has experienced this or just this one guy?

I think there's a suit that could go class action out there. https://www.google.com/url?sa=t&rct=...28153897,d.eWE