Another real world 'limp mode' experience and observations

I realize much has been written here about limp mode — here’s our real world experience.

We have 1300 miles on our i3 REX- all around our town over the past couple of months — Love the car - fun to drive and all that. I have a level 2 charger at home and rarely charge away from it.

Decided to take an extended trip of 106 miles from the foothills of Sacramento to the east bay around Oakland. We looked at it as an adventure. Unfortunately - on the trip back, the car went into limp mode during a 1000 foot freeway climb. The speed dropped to 28 MPH and was forced to the shoulder by a guy going 90 in the slow lane.

The purpose of this post is too share our experience with our first extended trip which we knew would activate the REX while looking to find a DC quick charge site at the 60 mile mark (Vacaville) during a lunch break.

Weather was perfect - primarily level ground - freeway traffic speed set at 75 in Eco Pro mode.

Observations:

• We knew there were few DC charging stations along the route. We had a location mapped out.
  Not all charging stations work. A great disappointment. Had to rely solely on REX.
  Not all charging stations are available when you want/need them.
  It is very much an early adopter experience not ready for prime time. There are just too few fast chargers. Once the number of EV's becomes significant the ‘away’ charging problem will be all the more apparent and frustrating.
  In spite of #4 we drove using gas to Whole Foods Lafeyette at the mile 95 mark— for a 20 minute charge to gave us 50 miles — A thumbs up experience. Got fully charged up at destination.

The return trip provided a thrill — With no place to charge - we drove back non-stop. A mistake. At mile 70, Rex turned on and we continued on for 25 miles or so at freeway speed. At mile 90, we started a gradual upslope. speed dropped from 75 to 64 mph. The last mile of freeway is a steep upslope of about 1000’. REX dropped to 28. SCARY!!!

Lessons learned —— You MUST have some battery in reserve for any significant hill climb. I’ve read there is a 56 MPH trick that I must learn that will lessen the precipitous speed drop on the freeway. I knew about limp mode — but somehow thought I was exempt because we had plenty of REX range left. Made no difference.

We love the i3 and the half dozen people who stopped by to talk about the car as it was charging or getting gas were very interested.

It is an ‘around town’ car. IMHO, it is not for trips greater than 70 miles if REX has to contend with any elevation change. Driving is an autonomic activity - requiring little thought EXCEPT for safety. For me, it is not worth the worry or additional thought planning getting from point A-B.

An interesting experience and right in line with other folks reports of the REx on a long hill. Had you made this trip in the UK or EU you would have been to start the REx at 80% charge in the Hold mode then you would have had enough power left in the battery to get you over the hill at full speed.

IMHO this behavior by the i3 is the cars biggest flaw and it is self inflicted. Only in America...... :roll:

+1

I would not talk anyone out of buying an i3. I think it's a very nice car that is fun to drive. It makes me smile!!! It is a car for use around town. The car was not designed for longer trips. That being said --- the car is flawed and has serious functional issues.

The ONLY notification that I received before going into limp mode was a "less than 15 miles remaining" message. At that point, within seconds I was steadily powered down to 28 MPH. My flawed thinking was that I had less than 3 miles to my final destination and I had 15 miles of range left. No sweat! Wrong!

We won't be taking any trips that might put us in jeopardy. It's a shame --- A great car that is flawed.

Let's hope for an effective and well engineered software fix.

KMP647 said:

You just can't have cars slowing down with no warning. Besides all the crippling that has occurred in the USA , the car should be screaming at you! And the displays should be flashing and warning you of the power situation.

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It's not like the car doesn't tell you your range is limited. The color changes, a message comes up. The car has a 34Hp motor compared to a 170Hp electric one. When your battery is low, guess how much power you can use? Climbing a long grade at speed sucks electrons fast.

If your trip is long enough and you don't recharge your battery, regardless of how often you refill the fuel tank or when you turn on the REx, you'll run into this situation if you live where it is hilly. People in the UK could see this, but those that live on the USA west coast where there are lots of mountains, often rising from the Pacific, you'll have to climb some grades, sometimes very long and very steep. The highest paved road in the USA is about 5x higher than the highest in the UK, the grades can go on for many miles.

Other than maybe one message, does your ICE 'scream' at you when it is about to run out of gasoline? The i3 is MUCH more graceful when you ignore the indications it's about to run out than any ICE that may mean no power steering, power brakes (depends on how much you use the brakes - they do have a little vacuum reserve on an ICE), and probably a few other things.

It really depends on where you're driving, how you're driving, and how long you're driving, how well the i3 will work out for you.

Au Contraire...your power supply is the battery. The REx just helps by trying (and that is KEY) to keep it up. The problem is, if you let the battery deplete beyond a certain range, regardless of when you can turn the REx on, if you keep going, eventually, your battery will get to that danger point. Climbing long grades at speed will keep chipping away at your battery capacity, regardless of how often you refill the gas tank. Even long trips at speed, depending on what you have turned on, could exceed the capacity of the REx.

So when Rex is running on flat ground for 30 miles is it not generating a bit of extra battery recharge?

I think those of you familiar with the grade up to El Dorado Hills would not expect the car to limp. Obviously, it did -- just not what a casual freeway driver would expect, for sure. The hill is about a 1000' elevation climb with the crest about 3/4 mile from the base. It is the first rise from sea level +- from the Sacramento Valley.

Regardless. +1 on software that gives meaningful warning of the impending limp. I cannot stress enough. Specifically, in my singular experience, we were a dangerous situation. Not good!!!

The REx can run at a few different output levels. It is programmed to essentially try to maintain, but it is not designed to recharge the batteries a la say a Prius or a Volt (or the i8). If your load goes down, the REx slows down, too and may just stop. IOW, it will only try to actually recharge the batteries above where they were if it is down into the critical area. So, as you drive, the batteries will either remain at their current level, or go down most of the time. So, on a long journey, any time you exceed the capacity of the REx, they go down, and eventually, regardless of how often you refuel, you could run into the situation where there is not enough charge to keep you going at full tilt.

IMHO, while some people can successfully use the i3 as a long-distance tourer, it is not. A car where you have to stop every hour or two to refuel just doesn't qualify. I find the i3 fun and fine for running around town, but much prefer my other car if I have to drive more than an hour anywhere. At some point, BMW will offer an electric more in the vein of the current Tesla, the i3 is not it.

Kudos for at least trying the trip.

I assume that climb was up i80 to Auburn or 50 to El Dorado Hills? Either one would be pretty brutal on the REx only. I drive from Roseville to Auburn every day in my Volt and I always think about the i3 and how I couldn't own one until they get the REx adjusted for real world use like they do for the Euro spec. Darn nice cars otherwise!

Look at a long trip in an i3 REx this way...in Europe, you can turn the REx on at 75% SOC. You drive until you run out of fuel, then maybe a few miles to get to a fuel station...your SOC drops a bit. Start up again, repeat, each time, if you do not hit an EVSE, your SOC drops. Eventually, you'll get into the critical area on SOC. If you never then hit a grade and try to climb at speed, you might be okay, but if your REx runs out of fuel, you're doubly in trouble. IOW, if you can always be guaranteed you can refill the fuel tank before it runs out, you can pretty much hold your SOC on the level...throw in some grades, lights, heated rear defroster, seat heaters, stereo going on high, cabin heating toasty, the REx will not be able to maintain, and your SOC keeps getting eaten away. The only way it all works is if you're route is not challenging, you don't drive all that fast, and you can keep the REx fed. Yes, people can use the REx for their only car, but you have to understand, it is NOT an ICE where you can stop at any fuel station, go many hundreds of miles, and refuel and keep going ad infinatum without limitations...the i3 will not do it. It works great for most people if their trips are within the best working range of the battery, or, your trip is not so far that you've exhausted both the battery SOC and the fuel, however many times you try to refill it...you must also eventually refill the batteries, as the REx just won't do it. The REx is essentially programmed (in all forms) to try to maintain the SOC above that critical area, and above that, doesn't really try to boost the battery level, but to maintain what you have. IT does that by adjusting how fast it runs and it cannot run fast enough to provide maximum power the i3 can try to pull from it.

Comparing it to a Volt is not apples to apples...the Volt has nearly 3x larger output engine than the REx, and it CAN recharge the batteries under most circumstances, and has a larger fuel tank to make your distance between stops reasonable to consider a long trip. Could BMW have designed a car like that? Yes, and it did in the i8. Will they do that for other new cars in the line? Almost certainly! WHen, only they know!

jadnashuanh said:

Look at a long trip in an i3 REx this way...in Europe, you can turn the REx on at 75% SOC. You drive until you run out of fuel, then maybe a few miles to get to a fuel station...your SOC drops a bit. Start up again, repeat, each time, if you do not hit an EVSE, your SOC drops. Eventually, you'll get into the critical area on SOC. If you never then hit a grade and try to climb at speed, you might be okay, but if your REx runs out of fuel, you're doubly in trouble. IOW, if you can always be guaranteed you can refill the fuel tank before it runs out, you can pretty much hold your SOC on the level...throw in some grades, lights, heated rear defroster, seat heaters, stereo going on high, cabin heating toasty, the REx will not be able to maintain, and your SOC keeps getting eaten away. The only way it all works is if you're route is not challenging, you don't drive all that fast, and you can keep the REx fed. Yes, people can use the REx for their only car, but you have to understand, it is NOT an ICE where you can stop at any fuel station, go many hundreds of miles, and refuel and keep going ad infinatum without limitations...the i3 will not do it. It works great for most people if their trips are within the best working range of the battery, or, your trip is not so far that you've exhausted both the battery SOC and the fuel, however many times you try to refill it...you must also eventually refill the batteries, as the REx just won't do it.

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I am sure you read Tom's post on the drive to Vermont from New Jersey. if not here is the link: http://bmwi3.blogspot.com/

While I understand what you said I tend to disagree and I sure don't understand why you keep knocking the Rex capability as it has been under attack far and away too much by BEV owners in my opinion. I guess it is because you have the BEV and have not experienced the REX.

Longer trips will rapidly become more common in the next few month's as the DC fast charger network is installed and as people start coding their cars to enable the Rex at will or are able to use the Rex software update with hill hold mode. I disagree with you big time in this area. I have the Rex myself and have done trips that exceed the battery capacity and now especially in the colder month's the Rex is crucial as the i3 BEV and Rex are out of juice in about 2/3 the distance that was advertised as the electric range. If you missed it, Tom's trip to Vermont saw him filling the Rex tank 3 times for a 250 mile trip and the time lost was 7 minutes total! Not a big deal in my book or a deal breaker if you need to drive further then the battery only can take you. In the article you will note the EV range when Tom left NJ with a full charge was only 48 miles in comfort mode. Without the Rex I would be selling my BEV right now had I bought the i3 without the Rex. Additionally Tom did not pamper the car on this trip like you suggest would be necessary, he drove 70 mph on the freeway and this was in very cold snow conditions where heating was used and some hills were even encountered. Yes common sense is important if you want to do a long trip, many of these articles involving the limp mode are the fault of the driver not thinking enough.

Where is your pioneering spirit, back in the day before the roads were even paved yet, still essentially wagon trails I suspect you would not have wanted to drive more than 2 or 3 miles from home. Gas stations were scarce as hens teeth and tires were not very reliable either.

I think to sum it up, those of us who bought the Rex and were most upset about no Rex hold mode in the US are the true modern day pioneers of the EV culture as we desire and will push the envelope; yes, even more than those of you who claim to be purists with the BEV. I know my i3 will get way more use in EV mode with the Rex than it would have had I purchased the BEV!

The day we can turn the REx on at 80% SOC is the day our i3 becomes our primary vehicle. Until then it is an addition to the fleet that lets us substitute electric miles for gasoline miles.....sometimes. The Hold will mode make it a practical all-around car and our first choice.

If you compare DC fast charging locations in CA verses the rest of the USA, you'll see a huge difference - there are very few. I did buy that capability in hopes that it would be useful. Having them, like in England, where they are along most of the major highways, makes the vehicle in either form much more useful on a longer trip. Until they become as common as gas stations with multiple pumps, as the EV fleet gets larger, you'll be in the situation where, IF the unit works, it may be in use, and if the people involved went maybe to lunch in the interim, you may have a long wait. IOW, even IF they exist, you may not be able to get to it! Same situation in the level 2 units...ICE vehicles tend to park in the spots, so they are not guaranteed. The situation will improve as the market for them grows and demand follows. But it is not going to happen overnight - fast in some terms, but not immediately.

Personally, while I like the i3, I do not find it all that great for a many hour-long trip compared to my other car, and even IF it could, it would not be my first choice. Personal issue, as I'm not the average size. THen, on my normal trip, I tend to fill my much bigger car up with things, and there just isn't room for people. Again, personal problem. The range hold function of the REx is just that - hold, and it can do that successfully until you stress it. If you have lots of those situations, until you can recharge, each time one of those events occurs, you'll drop your SOC. THat well is only so deep, even if you could turn it on at 100%. Now, if you live in the flatlands of the middle US, you may never be able to exceed the capacity of the REx to hold and could keep going as often as you fill up and keep the tank from empty...there are lots more people living where it is not as flat, and that won't happen. Because things are denser, you may not have to go as far to get where you want to go (there's more interesting places to stop verses mile after mile of corn fields). So, it may work, or it may not, but going into it expecting it to work well in all situations is unrealistic. It all depends on your route, how you drive, and your expectations. I don't feel I'm bashing, only being brutally realistic. It CAN work, it MIGHT not, it just depends on your situation.

I've read many posts here about the lack of hold option and was a bit concerned for my first range challenged trip.

I drove from Saratoga, CA to San Francisco and back this last Wednesday. Was in Eco pro mode up and back. Heat, wipers, headlights, etc. Left with full charge and fuel.

There are mild grades up and down on the way. So 45 miles or so at 70mph, then 8 miles of stop and go driving, each way.

After 30 miles of driving back, the Rex turned on. I never once suffered a reduction of speed on the highway. When I got home, I had only used 3/4 of a gallon...I am a happy camper.

No more reluctance to let her rip on the freeway. Incidentally, that ACC is amazing. In stop and go traffic, no matter the speed, you never use the pedals! The car accelerates and brakes to a stop all relative to the car in front.

I should add, this car is perfect for me and where I live.

Our most common long trip is up to the wine country and is about 200 miles. I have access to a 240v dryer plug in the garage of our destination and the final 30 miles of the trip is uphill in both directions. I don't see why I should not be able to start the REx at 80% (100% would be better) on the downhill and flat part of the trip leaving sufficient power for the last bit uphill. Even at 50% SOC at the start of the hills I would have enough juice to reach my destination on battery alone, much less with REx assist.

Granted, this may not be anyone else's trip profile, but it is ours...... Any reason why I shouldn't take my i3 next time instead of our ICE and give it a try? Once the KLEs are replaced and I can code my car, of course......

jadnashuanh said:

If you compare DC fast charging locations in CA verses the rest of the USA, you'll see a huge difference - there are very few. I did buy that capability in hopes that it would be useful. Having them, like in England, where they are along most of the major highways, makes the vehicle in either form much more useful on a longer trip. Until they become as common as gas stations with multiple pumps, as the EV fleet gets larger, you'll be in the situation where, IF the unit works, it may be in use, and if the people involved went maybe to lunch in the interim, you may have a long wait. IOW, even IF they exist, you may not be able to get to it! Same situation in the level 2 units...ICE vehicles tend to park in the spots, so they are not guaranteed. The situation will improve as the market for them grows and demand follows. But it is not going to happen overnight - fast in some terms, but not immediately.

Personally, while I like the i3, I do not find it all that great for a many hour-long trip compared to my other car, and even IF it could, it would not be my first choice. Personal issue, as I'm not the average size. THen, on my normal trip, I tend to fill my much bigger car up with things, and there just isn't room for people. Again, personal problem. The range hold function of the REx is just that - hold, and it can do that successfully until you stress it. If you have lots of those situations, until you can recharge, each time one of those events occurs, you'll drop your SOC. THat well is only so deep, even if you could turn it on at 100%. Now, if you live in the flatlands of the middle US, you may never be able to exceed the capacity of the REx to hold and could keep going as often as you fill up and keep the tank from empty...there are lots more people living where it is not as flat, and that won't happen. Because things are denser, you may not have to go as far to get where you want to go (there's more interesting places to stop verses mile after mile of corn fields). So, it may work, or it may not, but going into it expecting it to work well in all situations is unrealistic. It all depends on your route, how you drive, and your expectations. I don't feel I'm bashing, only being brutally realistic. It CAN work, it MIGHT not, it just depends on your situation.

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One thing you say is incorrect though, once in Rex hold at say 75% and you exceed the output of the Rex and use battery to climb a steep hill, when your load on the Rex is reduced it will recharge the battery back up to the hold point. So your inference at loosing battery SOC frequently and not getting it back without a EVSE is incorrect. Just saying! I know this is true as I tried it.

WoodlandHills said:

Our most common long trip is up to the wine country and is about 200 miles. I have access to a 240v dryer plug in the garage of our destination and the final 30 miles of the trip is uphill in both directions. I don't see why I should not be able to start the REx at 80% (100% would be better) on the downhill and flat part of the trip leaving sufficient power for the last bit uphill. Even at 50% SOC at the start of the hills I would have enough juice to reach my destination on battery alone, much less with REx assist.

Granted, this may not be anyone else's trip profile, but it is ours...... Any reason why I shouldn't take my i3 next time instead of our ICE and give it a try? Once the KLEs are replaced and I can code my car, of course......

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I would think once you code the Rex hold you would not have any issues with your route. I do believe though that 75% is the maximum hold point you can set for the Rex hold function. It may even be possible with the new hill hold software update do out in March without coding the manual hold function. We will have to wait and see how that is implemented.

mind machine said:

… Where is your pioneering spirit, back in the day before the roads were even paved yet, still essentially wagon trails I suspect you would not have wanted to drive more than 2 or 3 miles from home. Gas stations were scarce as hens teeth and tires were not very reliable either. …

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Range anxiety is a misnomer. When pushing to the edge of max. range in a BEV, I suffer charging anxiety.

How’s this for pioneering spirit, in the heart of winter, with a Level 2 at the destination, the only one within range: Driving 80 miles in an i3 BEV, or driving 80 miles in a BEV+Rex? Who has the tougher “road” to hoe? The BEV driver's range extender is a tow truck. (Or we can chicken out and take the diesel wagon to the Christmas party.)

mind machine, I see you're in Ohio. In late 2014, the closest SAE Combo DCFC station to central Ohio is in Dundwoody, Ga., on the north side of Atlanta, about 570 miles away from Columbus. There is a closer station, about 425 miles away, in Toronto. Why wouldn’t an ICE driver think twice, from Ohio's state capitol, about reaching either of those destinations in a day?

I’m not knocking the REx. It’s peace of mind. It greases the skids. It gets more people on the EV super train. But let’s not forget what literally drives the i3 and what it truly is — a nimble city car. That is its DNA. More power to those whose need the scooter-engine stopgap today. I can't wait to drive a loaner REx.

As the SAE Combo DCFC network expands — and 2015/16 will be the catalyst on the East Coast— that $4K peace of mind will become superfluous for more of us present and future outli3rs.

websterize said:

mind machine said:

… Where is your pioneering spirit, back in the day before the roads were even paved yet, still essentially wagon trails I suspect you would not have wanted to drive more than 2 or 3 miles from home. Gas stations were scarce as hens teeth and tires were not very reliable either. …

Click to expand...

Range anxiety is a misnomer. When pushing to the edge of max. range in a BEV, I suffer charging anxiety.

How’s this for pioneering spirit, in the heart of winter, with a Level 2 at the destination, the only one within range: Driving 80 miles in an i3 BEV, or driving 80 miles in a BEV+Rex? Who has the tougher “road” to hoe? The BEV driver's range extender is a tow truck. (Or we can chicken out and take the diesel wagon to the Christmas party.)

mind machine, I see you're in Ohio. In late 2014, the closest SAE Combo DCFC station to central Ohio is in Dundwoody, Ga., on the north side of Atlanta, about 570 miles away from Columbus. There is a closer station, about 425 miles away, in Toronto. Why wouldn’t an ICE driver think twice, from Ohio's state capitol, about reaching either of those destinations in a day?

I’m not knocking the REx. It’s peace of mind. It greases the skids. It gets more people on the EV super train. But let’s not forget what literally drives the i3 and what it truly is — a nimble city car. That is its DNA. More power to those whose need the scooter-engine stopgap today. I can't wait to drive a loaner REx.

As the SAE Combo DCFC network expands — and 2015/16 will be the catalyst on the East Coast— that $4K peace of mind will become superfluous for more of us present and future outli3rs.

Click to expand...

No you are a true pioneer in my book, but you live in Maryland where I bought my plugin Prius (Russel Toyota in Baltimore) and there are way more level 2 locations there than Ohio. Anyway I am counting on the BMW dealers installing at least the Bosch DC fast chargers, I know not quit as fast but still a fast dc charge and my dealer claims that BMW dealers are required to start installing them around the first of the year. While not the best, but still if any dealer selling i3's has the DC fast charger and they allow any BMW owner to stop in and use them. You see what I am thinking.

Anyway here in Ohio without much infrastructure the Rex was a must have for me. I live 50 miles from a big city period, rural if you will OHIO!

A few weeks ago, I'd asked the service manager of the BMW dealership where I got my i3 about the fast chargers, and he said they were not currently planning to install one...now, BMW may be applying a bit more pressure, but just like the loaner program being voluntary, I'm not sure they can force the dealers to do it if they do not want to. I hope they do put one in, but as of now, I'm not sure it is a requirement for them. Maybe things have changed in the last few weeks.

jadnashuanh said:

A few weeks ago, I'd asked the service manager of the BMW dealership where I got my i3 about the fast chargers, and he said they were not currently planning to install one...now, BMW may be applying a bit more pressure, but just like the loaner program being voluntary, I'm not sure they can force the dealers to do it if they do not want to. I hope they do put one in, but as of now, I'm not sure it is a requirement for them. Maybe things have changed in the last few weeks.

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I was at my dealer on wednesday (12/17) of this week and that is when I was told by the i genius that BMW was pushing dealers to start installing the DC chargers early next year. Anyway that is part why I bought the Rex in the first place, I know it will take some time. I have two other cars a 2014 Prius plugin advanced and a 2013 Lexus Rx 450h, but I like driving the BMW more then either of them. We use the Prius on trips to Williamburg VA and Connecticut when we travel that far, but if I could reasonably do it I would take the i3.