New i3 REX owner, coding question.

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jay93

Member
Joined
Jul 9, 2020
Messages
5
Hi all,

I am the proud new owner of a 2017 i3 REX. Coming from a Chevy Spark EV so this is a huge upgrade. So far Im very impressed with the range and love the adaptive cruise control.

Anyways, I am looking into doing the coding with bimmercode to allow for the battery hold feature, and unlock full gas tank capacity. While watching a tutorial I noticed that the ECM resets itself as part of the process, will that end up clearing the service data/reminder? If so would that cause trouble when I go In for service?

Thank you :)
 
I also have a 2017 REx and coded HSOC with BimmerCode. The service reminders in my car weren't reset after coding, so nothing to worry about there. I recently had my car at the local BMW dealership for its annual service. They either didn't notice that I'd coded several features to "non-default" values or they didn't care. They said nothing about it and the car was still coded when they were done with it.

Your 2017 should have the middle-sized 94 Ah battery pack. Only the original 60 Ah battery pack was programmed from the factory with the software-limited gas tank, so you shouldn't have to worry about the gas tank at all. You already have the full capacity available without coding.
 
richs said:
I also have a 2017 REx and coded HSOC with BimmerCode. The service reminders in my car weren't reset after coding, so nothing to worry about there. I recently had my car at the local BMW dealership for its annual service. They either didn't notice that I'd coded several features to "non-default" values or they didn't care. They said nothing about it and the car was still coded when they were done with it.

Your 2017 should have the middle-sized 94 Ah battery pack. Only the original 60 Ah battery pack was programmed from the factory with the software-limited gas tank, so you shouldn't have to worry about the gas tank at all. You already have the full capacity available without coding.
Click to expand...

Oh awesome! Hopefully my dealership is cool with it as well.

That’s correct mine is the 94ah battery. I didn't know the full gas tank capacity was already unlocked.

Thank you.
 
BMW chose to meet a requirement for California that said that to get all of the HOV and environmental benefits, a hybrid could not get more range on the engine than it could on the batteries alone...so, BMW chose to electronically limit the car's ability to use all of the gas in the tank (it's the same tank as used elsewhere). But, once the battery size was enlarged, since the gas tank didn't get larger, too, the car could go further on electricity than the engine assisted range, so there was no need. To keep with the spirit of the CA rules, they also forced the REx to not come on until the SOC got to 6%. That could lead to issues, as a 34Hp motor doesn't produce enough electricity to keep a 170Hp electric motor turning except if the electric motor is not heavily loaded (high speeds, big electrical loads like heating/lights, climbing a long grade, etc.). So, as the SOC dropped, you might then be limited by the power left. In the rest of the world, you can opt to turn the REx on once the SOC got below 75%. In some places, you either have to pay a big fee or are unable to drive in the center of the city unless you can run on electricity, so being able to 'save' some battery capacity by running the REx earlier makes a lot of sense. The reason for not being able to turn it on at 100% or more than 75% is that under some circumstances, regen would not have any capacity to store that energy. The car will automatically start to use the brakes, but it's lots more efficient to just store that energy rather than waste it by heat in the braking system!
 
jadnashuanh said:
BMW chose to meet a requirement for California that said that to get all of the HOV and environmental benefits, a hybrid could not get more range on the engine than it could on the batteries alone...so, BMW chose to electronically limit the car's ability to use all of the gas in the tank (it's the same tank as used elsewhere). But, once the battery size was enlarged, since the gas tank didn't get larger, too, the car could go further on electricity than the engine assisted range, so there was no need. To keep with the spirit of the CA rules, they also forced the REx to not come on until the SOC got to 6%. That could lead to issues, as a 34Hp motor doesn't produce enough electricity to keep a 170Hp electric motor turning except if the electric motor is not heavily loaded (high speeds, big electrical loads like heating/lights, climbing a long grade, etc.). So, as the SOC dropped, you might then be limited by the power left. In the rest of the world, you can opt to turn the REx on once the SOC got below 75%. In some places, you either have to pay a big fee or are unable to drive in the center of the city unless you can run on electricity, so being able to 'save' some battery capacity by running the REx earlier makes a lot of sense. The reason for not being able to turn it on at 100% or more than 75% is that under some circumstances, regen would not have any capacity to store that energy. The car will automatically start to use the brakes, but it's lots more efficient to just store that energy rather than waste it by heat in the braking system!
Click to expand...

Ah good old California regulations. Luckily I don't travel long distances too often but I do make a couple trips a year to the Bay Area so unlocking that range hold will be a must for me.
 
One more quick question.... doesn't warrant creating another thread.

My Chevy Spark would run thermal management as needed as long as it was plugged in. Does the i3 do the same? I read the manual and don't see anything about it.

Thank you!
 
jay93 said:
My Chevy Spark would run thermal management as needed as long as it was plugged in. Does the i3 do the same? I read the manual and don't see anything about it.
Click to expand...
Whenever an i3 is in the drive readiness state, is charging, or its battery pack is being preconditioned, thermal management is on to maintain the battery pack temperature within an acceptable temperature range. However, when parked, off, and not preconditioning, thermal management is off, so parking over hot pavement on a hot day for several hours might result in the battery pack temperature exceeding its heat limit just as parking outside on a cold day could result in the battery pack temperature dropping below its optimum temperature range. In either case, the battery pack's output power would be reduced to protect the battery cells until the pack temperature enters the acceptable temperature range.

Preconditioning is heating or cooling the battery pack prior to departing so that its temperature would be in the acceptable range. Preconditioning must be enabled by setting a departure time, manually activating preconditioning, and connecting to an EVSE; i.e., preconditioning isn't automatic.
 
alohart said:
jay93 said:
My Chevy Spark would run thermal management as needed as long as it was plugged in. Does the i3 do the same? I read the manual and don't see anything about it.
Click to expand...
Whenever an i3 is in the drive readiness state, is charging, or its battery pack is being preconditioned, thermal management is on to maintain the battery pack temperature within an acceptable temperature range. However, when parked, off, and not preconditioning, thermal management is off, so parking over hot pavement on a hot day for several hours might result in the battery pack temperature exceeding its heat limit just as parking outside on a cold day could result in the battery pack temperature dropping below its optimum temperature range. In either case, the battery pack's output power would be reduced to protect the battery cells until the pack temperature enters the acceptable temperature range.

Preconditioning is heating or cooling the battery pack prior to departing so that its temperature would be in the acceptable range. Preconditioning must be enabled by setting a departure time, manually activating preconditioning, and connecting to an EVSE; i.e., preconditioning isn't automatic.
Click to expand...

Interesting. I came out a few days ago after my 2014 i3/Rex had been parked in the hot sun for several hours and heard a fan or pump or something running. I just figured it was doing battery pack temp management. But you're saying that the i3 doesn't do this when parked, not plugged in, and not preconditioning?
 
My 2015 REX runs its compressor sometimes when plugged in on hot days, even when just plugged in to 110V.
 
Fisher99 said:
Interesting. I came out a few days ago after my 2014 i3/Rex had been parked in the hot sun for several hours and heard a fan or pump or something running. I just figured it was doing battery pack temp management. But you're saying that the i3 doesn't do this when parked, not plugged in, and not preconditioning?
Click to expand...
I don't live in a climate that would heat the battery cells enough when parked to require cooling, so I can't test this. I'm relying on reports by several i3 owners living in Las Vegas and Phoenix who have reported reduced power when driving after having been parked over hot pavement in direct sunlight for several hours. If automatic battery pack cooling had occurred, their battery packs wouldn't have been so hot that their output power was reduced.

Also, if automatic battery pack cooling or heating were implemented, there would be no need for manual battery pack preconditioning. There would also be a significant risk of discharging the battery pack while parked so much that an i3 would be unable to reach its destination without stopping to charge. I've never read of this happening.

I have heard the cooling fan for the coolant radiator and A/C condenser behind the front air intake grill running with our i3 off, not charging, and not being preconditioned. However, this was immediately after shutting off after driving, not hours after parking.

I've never read that the i3 implements automatic battery pack cooling or heating while parked, not charging, and not preconditioning. I've looked for this in Owner's Manual, David Bricknell's Electric Vehicles and the BMW i3 book, BMW's Training Manuals, and on the New TIS Website. I would think that this would be important enough to highlight. Maybe I've just missed it.
 
Very interesting. Car wasn't plugged in and temps were only in the low 90's. Came out a few hours after I had last driven it and heard the fan running. We have had high 90's weather since and I've only seen this happen that once, although I guess that doesn't mean that it hasn't happened when I wasn't there to observe it. The car parks in my driveway so is in direct sunlight most of the day.
 

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