carlllefong1
Posts: 6
Joined: Thu Jan 07, 2021 9:56 am

Question from Newbie

Thu Jan 07, 2021 1:06 pm

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
Posts: 615
Joined: Mon Sep 09, 2019 5:33 pm

Re: Question from Newbie

Thu Jan 07, 2021 2:30 pm

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.
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jadnashuanh
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Location: Nashua, NH USA

Re: Question from Newbie

Thu Jan 07, 2021 7:30 pm

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.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

carlllefong1
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Joined: Thu Jan 07, 2021 9:56 am

Re: Question from Newbie

Thu Jan 07, 2021 9:12 pm

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
Posts: 615
Joined: Mon Sep 09, 2019 5:33 pm

Re: Question from Newbie

Thu Jan 07, 2021 10:06 pm

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.
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jadnashuanh
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Location: Nashua, NH USA

Re: Question from Newbie

Thu Jan 07, 2021 10:40 pm

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.
Jim DeBruycker
2014 i3 BEV, 2021 X5 45e
(The i3 will be sold soon, <17K-miles, interested?)

carlllefong1
Posts: 6
Joined: Thu Jan 07, 2021 9:56 am

Re: Question from Newbie

Thu Jan 07, 2021 11:45 pm

Thanks! This is very helpful.

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MKH
Gold Member
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Joined: Fri Nov 02, 2018 5:48 am
Location: Dallas

Re: Question from Newbie

Fri Jan 08, 2021 10:44 am

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/
Mark H.
2015 i3 Rex, Capparis White, Tera World, Technology & Driving Assistant, Parking Assistant, Harman Kardon Audio System, 19 inch 427 wheels, EVoInnovate EVSE

carlllefong1
Posts: 6
Joined: Thu Jan 07, 2021 9:56 am

Re: Question from Newbie

Fri Jan 08, 2021 11:38 am

Thank you! Sounds easy, even for a rookie.

JohnWasser
Posts: 81
Joined: Sat Mar 07, 2020 6:15 pm

Re: Question from Newbie

Fri Jan 08, 2021 12:03 pm

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.

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