Question from Newbie

[carlllefong1]

I am thinking about buying a CPO 2017 I3 Rex from a dealer that is about 200 miles from my house. I am not sure I understand the function and limitations of the Rex system, and I was hoping that someone could explain to me whether it would be possible to make that trip, mostly over Interstate Highway, in a single day. Thanks in advance.

 

[eNate]

Yes, absolutely.

You have three options.

Leave with a full charge and let the Rex take you the final 80 or 90 miles,

Or stop and charge at a DC fast charge location for about 40 minutes, or perhaps two charging stops for shorter durations (check plugshare.com or the ABRP app - A Better Route Planner),

Or code your car to enable "hold state of charge" (HSOC) before departing so you can turn the Rex on early in your journey.

I'd personally plan the charging stop(s), assuming there are options between here and there.

 

[jadnashuanh]

The i3 always is running off of the electricity (there's no connection of the engine to the wheels), but when the REx is on, it is applying power only to the motor and any excess back into the batteries. But, the REx engine is quite small, so if you let the batteries get drawn down near empty, the only power you'll have is the electricity provided by the engine (somewhere between 34-38Hp, not much - enough to let you continue as long as you're not trying to climb a long grade, where you'll eventually slow down since there's not enough power to keep going at speed).

So, the goal is to keep the batteries up above say 10%, and stop and refill the gas tank. Ideally, you'd reprogram the engine so you can manually switch it on earlier, otherwise, it won't come on by itself until the battery gets to 6% or so. If you program it, you can turn it on anywhere below 75%, and if you keep fuel in the tank, you can just keep going that way. The engine isn't super efficient, maybe mid-30mpg range while on batteries, it's closer to 113 mpge. When the batteries get down low, the engine will speed up, making it less efficient. Prior to that, if you've enabled it after programming, the rpm will vary to match the load. The REx is designed to hold the power (if possible) at the point when you turn it on. IT gets reset when you shut the vehicle off, though, so if you stopped for fuel at 50% charge, that's the highest it would ever get until you recharged the batteries at home or on the road.

So, 200-mile trip is totally possible, but you have to understand how things work or you'll be in for a surprise.

 

[carlllefong1]

Thank you both for the advice. It sounds like it is important to code it so that HSOC is available. Is coding something I can do or does it require special hardware/software that the owner does not have access to (and if that is the case, is there a source for finding someone to do it)?

 

[eNate]

I haven't done it myself — I'm a BEV owner — but I'm aware of other owners who've taken the tool with them and done it right after purchase for the drive home.

Check out YouTube for how to videos. You'll need an app and a dongle.

But really, unless finding a mid point charging location is out of the question, that's the least stressful option IMHO.

 

[jadnashuanh]

FOr about $50 you can buy the OBD-2 device and BimmerCode license (versions for both Android and iOS - download it and run in demo mode to get an idea - that doesn't cost you anything) and do it in a few minutes. Go to www.bimmercode.app before you buy an adapter to make sure you get one that will work in the i3 for the phone or tablet you have and you can view the list of things you can change while you're at it. It's really pretty simple. If you want to do something more complex, then, it can become a bit more involved, but this is pretty much picking options off of a list and hitting the code button and waiting for it to happen.

 

[carlllefong1]

Thanks! This is very helpful.

 

[Anonymous]

As Jim posted, Bimmercode for either iPhone or Android (in the app store) and one of the recommended OBD dongles. Compatible ones tested with Bimmercode are listed on their site. It's not really coding or programming, just activating a hidden iDrive menu item that is there on the European i3s. Very simple, you just select the 'change' in the Bimmercode app, and apply it. Did it on mine and it takes all of two minutes. https://bimmercode.app/

 

[carlllefong1]

Thank you! Sounds easy, even for a rookie.

 

[JohnWasser]

Check the PlugShare app. The icon on the map that looks like a funnel is the 'Map Filters' menu. Turn off "Requires Fee" to find free chargers. Set "Minimum kilowatts" to 50 or turn on only "CCS/SAE" plugs to find only DC Fast Chargers. With luck, there will be a FREE DC Fast Charger on the way home!

If none, turn on "Requires Fee" and pick from the DC Fast Chargers on the route. Expect about $0.30/minute for charging and 40 minutes ($12) for most of a charge. At some point between an 80% charge and a 95% charge, the charge rate will slow way down. You might go from 10% to 90% in 40 minutes but the next 10% (90->100%) will take ANOTHER 40 minutes (and another $12).

It would be good to sign up for and install apps for major charging networks: ChargePoint, EVgo, Electrify America.

 

[carlllefong1]

Thanks! I will get all of these apps.

 

[frictioncircle]

Hello, carlllefong1 –

Regarding coding hold-state-of-charge on the CPO 2017 i3 REx that you're considering purchasing and your potential road trip...

Coding an i3 REx for maximum fuel tank size and hold-state-of-charge engagement level is definitely something you can do if you have a paid version of Bimmercode and a compatible OBD-II Bluetooth dongle. Check here to see the dongles Bimmercode supports: https://bimmercode.app/adapters/

I've been coding my i3 since 2014 and it's never been a two-minute process. The first time you connect your phone / tablet to the car using Bimmercode it will take 3-4 minutes just to read which ECUs (computer modules) are in your car.

Once you know which ECU you want to code (HU_ENTRYNAV should be the one for Hold-State-Of-Charge) Bimmercode will take about three minutes to read all the code-able options for that ECU.

Once you make a change to one of the variables it needs to be resaved in the ECU which takes another three minutes.

Just wanted to let you know that while it seems like making a coding change should be lightning quick, in reality changing just one parameter in a single ECU will take about 10 minutes.

 

[frictioncircle]

One more thing...

The suggestion to get the PlugShare app is a very good one, PlugShare has some of the most accurate charging station info.

As you're new to EVs and planning on a long-distance drive to get your new ride home, have a Plan A and a Plan B for charging.

You may have a charging station in mind but what will you do if it's occupied when you arrive? Normally the driver will be in the car and ready to move off when her car is charged – but maybe she went into the mall for a few hours!

You may have a charging station in mind but it will be blocked by a gas / hybrid driver using the parking space (welcome to being ICEd!)

Finally, you may have a charging station in mind but it will be out of service when you pull up to charge (PlugShare is pretty accurate with station condition information in this situation).

Some station faults can be reset by calling the station's operator (ChargePoint, Blink, Greenlots, etc.) but do have an alternate charging solution in case your first choice is offline.

 

[frictioncircle]

Finally, a well-written article with good REx information:

https://www.bmwblog.com/2016/06/01/bmw-i3-rex-lawsuit-howd-happen-whos-really-fault/

 

[carlllefong1]

Hey Friction, thanks for the link to the long-form article about REx function/limitations. In all of my research I had never heard about the Class Action lawsuit. The article is very well written, and is actually reassuring to someone who lives and will be driving in the Low Country of Georgia (flat as a pancake). I am curious as to whether anyone who has coded their i3 has been denied coverage for a warranty repair.

 

[alohart]

I am curious as to whether anyone who has coded their i3 has been denied coverage for a warranty repair.

One member of this forum who used his early REx to earn money was denied warranty coverage when his REx engine suffered a catastrophic failure. He had coded HSOC, and his REx had been driven over 100k miles, so the REx engine had far more use than normal. A BMW dealer apparently told him that the REx system was not intended to be used as he had used it. He didn't appeal this decision despite many i3 owners urging him to do so. He had apparently bought another vehicle and merely parked his REx.

Coding HSOC merely implements the behavior of the REx system in most other markets around the world, so there's nothing about this change that should result in the voiding of one's warranty. Also, coding BMW vehicles has been occurring before the i3 was introduced, so it's nothing new. However, this doesn't mean that some dealers might try to deny warranty coverage.

 

[jadnashuanh]

Early on in the release of the i3, there was some discussion based on some BMW scuttlebutt that essentially said, the REx was added based on marketing people rather than because the engineers wanted it. Based on how the whole vehicle was conceived, when used as intended, there'd be no reason to add that extra 350# or so when they were sweating grams of weight to optimize efficiency. The marketing people felt that range anxiety was too big of a hurdle. Given that, it does add functionality, but keep in mind, it really is just a depowered moped engine, and they generally aren't designed for huge numbers of miles, either.

I haven't read the fine print on the warranty, but there may be a clause in there about commercial use.

 

[frictioncircle]

Hey Friction, thanks for the link to the long-form article about REx function/limitations. In all of my research I had never heard about the Class Action lawsuit. The article is very well written, and is actually reassuring to someone who lives and will be driving in the Low Country of Georgia (flat as a pancake). I am curious as to whether anyone who has coded their i3 has been denied coverage for a warranty repair.

That article was written by Tom Moloughney. He is an early i3 owner and enthusiast and has a very good relationship with BMW i. His information is reliable and he often had an inside line on developments within the i operation. If you come across other articles by him, they will definitely be accurate.

A quick, clarifying note about coding – it's something you can do the minute you get the keys for your i3 as long as you have the OBD-II dongle and the right software. I just wanted to let you know that you'll be sitting in the driver's seat wondering why it's taking so long to make a change to a single variable. Be patient... it works just fine but the process is so much slower than one might expect.

I've coded my 2014 BEV for the past five years and have never had the slightest pushback when making a warranty claim at a dealer.

BMW was ahead of the game with i in the mid-2010s – it's been so sad to see how they mismanaged their Act II.

The journey from having two unique interpretations of transport built from carbon fiber & aluminum in 2014 to (seriously?) a 3er hybrid in 2021 is nothing but a study in a great lead squandered.

edit: grammar, and added warranty details

 

[eXodus]

Early on in the release of the i3, there was some discussion based on some BMW scuttlebutt that essentially said, the REx was added based on marketing people rather than because the engineers wanted it. Based on how the whole vehicle was conceived, when used as intended, there'd be no reason to add that extra 350# or so when they were sweating grams of weight to optimize efficiency. The marketing people felt that range anxiety was too big of a hurdle. Given that, it does add functionality, but keep in mind, it really is just a depowered moped engine, and they generally aren't designed for huge numbers of miles, either.

As far as I know the Rex was always part of the concept. Only the US-implementation due to laws is bad.
I worked with the Mini-E prototype back in 2010 in Munich. (Which had more range and power then the first i3)
https://en.wikipedia.org/wiki/Mini_E

Here are some rumors I heard of Requirements BMW had back then for Project i

1. The old batteries should become storage for homes in second life
https://www.carscoops.com/2016/06/bmw-builds-home-storage-unit-from-used/
2. Range extender should be able to power a home
3. There was fierce competition within BMW for any new product line
4. When the executive saw the BMW Vision i concept cars he asked: "Can we build them exactly like that?"
https://www.automobilemag.com/news/bmw-project-i-becomes-reality/
5. There was a concept for an i1 and
6. The REX was envisioned as a the 1.5L the i8 got

 

[Anonymous]

keep in mind, it really is just a depowered moped engine, and they generally aren't designed for huge numbers of miles, either.

Actually,the i3's range extender is based on BMW's C 650 scooter engine. This engine, in the scooter version is rated at 65 hp @ 7500 RPM. However, as the range extender, it is de-rated to 35 hp since all it is doing is spinning a generator to produce electricity. Many 650's on the road with 100,000 miles plus on them still going strong. People in the market for a used 650 are usually quite happy if they can find a 'low-mileage' one in good shape with only 50K to 60K miles on it. ("Scooter" in Europe is somewhat different than "Scooter" in the USA). In the EU the 650 is a common commuter and road-trip bike.

Scooter - Europe

View attachment scooter.jpg



Scooter - USA