To buy or not to buy 2015 i3 REx - battery concerns

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grinning

Member
Joined
Jan 20, 2021
Messages
9
So, I am half way through a 7 day trial period on the car. I love the way it drives and the interior quality and layout. The range extender seems to work great, and gives me the freedom to drive over the all electric range. The issue I have is how short that electric range is compared to new. I am getting just about 50 miles with an average driving efficiency of 3.6 mi/kwh. That math comes up to less than 14 kwh battery capacity, which is around 73% of the 18.8 it started out at. It is winter here in Ohio, with temps in the low 40s.

Is it likely that the capacity will increase as I complete a few charging cycles, given it likely sat on a lot for some time?

Is low to mid 40s cold enough to bring my capacity down this low?

I have the the max kapa test trick on on the display panel, and get around 14.5-14.6 each of the three times I have checked (one time per charge cycle I have done).

Should I pass on this car and try another, or is this normal enough that I should roll with it?

On a side note, the first time I took it out, the battery hit 4 miles left, and the REx kicked in... then kicked off and I got an error saying I could use the edrive only. I just barely managed to limp home at low speed. I don't know if that is relevant here or not.

Thanks,
Jacob
 
grinning said:
Is it likely that the capacity will increase as I complete a few charging cycles, given it likely sat on a lot for some time?
I doubt it.

grinning said:
Is low to mid 40s cold enough to bring my capacity down this low?
I don't think that battery pack temperature affects capacity very much. However, low temperatures certainly reduce efficiency. You could precondition (i.e., preheat) the battery pack by setting a departure time which would increase your driving efficiency and thus range. Warmer weather should also increase your driving efficiency and range. Our 2014 BEV has averaged 5.2 mi/kWh over its lifetime which doesn't include any ambient temperature below 70 ºF. Its current Batt. Kapa, max is 15.2 kWh and gradually decreasing which is disappointing having driven only ~11k miles.

grinning said:
Should I pass on this car and try another, or is this normal enough that I should roll with it?

On a side note, the first time I took it out, the battery hit 4 miles left, and the REx kicked in... then kicked off and I got an error saying I could use the edrive only. I just barely managed to limp home at low speed. I don't know if that is relevant here or not.
I would be particularly concerned about the REx problem. Unless you have an extended warranty that would cover diagnosing and repairing the REx problem, this could be an expensive repair, or it could be due to a defective, inexpensive fuel pump relay.

I would also be concerned about the low battery pack capacity. You could get lucky and have the battery pack replaced under warranty eventually. However, you would have to pay a BMW dealer to measure the battery pack capacity which would cost over $200. Many others who have paid for this capacity measurement have discovered that the capacity has increased somewhat during the capacity measurement resulting in no warranty replacement.

Because of these problems, I would pass on this car. Buy a 2017 or later, if possible, because fewer Rex problems seem to occur and battery capacity loss seem to minimal compared with many 2014-2016 battery packs.
 
Thanks for the in depth reply. For the REx issue, I forget to mention it has worked fine ever since I got it home a charged to full for the first time. I suspect the 12v battery was too low. It does make me a little worried, as I will rely on it to get to and from my airport that is 70 miles from home.

Jacob
 
You might be running with the original 12v battery, which is nearing end-of-life, or it could have just been discharged from being parked for an extended amount of time. Are you pre-conditioning? What is your daily max commute/use going to be? My 2015's range below 50 degrees F is low 50's. At 60 degrees, its' 60+, above 70 and its 70+. (72 being the stated factory range). Though this year, winter range seems lower than last year, but we may be getting more cold days as well, not sure. Here is a good article on winter range-drop. This morning it is 46 degrees here and fully charged am showing a range of 55 miles.

https://insideevs.com/news/324474/bmw-i3-winter-range-reduction-amp-tips-for-offsetting-cold-weather-impact/
 
I have tried preconditioning, with no real effect.

I work from home, so don't have a regular commute. For running around town, the 50 mile range would be just fine. However, I have a 70 miles drive to my airport that I make on average once or twice per month. I may, ot may not be able to charge while parked at the airport. The only long term lot with charging available is closed for covid-19.

MKH said:
You might be running with the original 12v battery, which is nearing end-of-life, or it could have just been discharged from being parked for an extended amount of time. Are you pre-conditioning? What is your daily max commute/use going to be? My 2015's range below 50 degrees F is low 50's. At 60 degrees, its' 60+, above 70 and its 70+. (72 being the stated factory range). Here is a good article on winter range-drop.

https://insideevs.com/news/324474/bmw-i3-winter-range-reduction-amp-tips-for-offsetting-cold-weather-impact/
 
For the airport commute, if me, I'd definitely use Bimmercode to 'unhide' the option to activate the REx engine on demand when the charge is below 75%, plus remove the limiter on how much fuel you can use per tank. That twice a month airport run is pretty much exactly what the REx is for. When I need to run the rare trip that will be beyond my electric range, I turn on the REx at 75%, and keep the electric range high and in reserve to use at the end of the trip if needed instead of the beginning.

https://bimmercode.app/
 
MKH said:
For the airport commute, if me, I'd definitely use Bimmercode to 'unhide' the option to activate the REx engine on demand when the charge is below 75%, plus remove the limiter on how much fuel you can use per tank. That twice a month airport run is pretty much exactly what the REx is for. When I need to run the rare trip that will be beyond my electric range, I turn on the REx at 75%, and keep the electric range high and in reserve to use at the end of the trip if needed instead of the beginning.

https://bimmercode.app/

That is exactly what I planned on doing. The car came with the option to turn on the REx manual already enabled.

However, this morning I decided to return this car and keep looking. Even if the REx seems to be working fine now, that experience of it failing on me spooked me. I often land at the airport late at night, and then have a long drive as late as midnight to get home. I really need a system that is just going to work flawlessly, and this just doesn't seem to be that. So, for now, I will be back to my good old dirty 2011 Miata. I do really like the i3, and might save up money for a newer model at some point.

Thanks,
Jacob
 
Yeah that REx hiccup might give me 2nd thoughts too.


With that 7 day trial, was it a Carmax car?? One advantage of a Carmax buy is their add-on extended warranty is about the best around and well worth it. Anything goes South, drop if off at Carmax, they drive it over to a BMW Dealer for repair, and pick up the tab.
 
MKH said:
Yeah that REx hiccup might give me 2nd thoughts too.


With that 7 day trial, was it a Carmax car?? One advantage of a Carmax buy is their add-on extended warranty is about the best around and well worth it. Anything goes South, drop if off at Carmax, they drive it over to a BMW Dealer for repair, and pick up the tab.

It was Carvana.
 
Not sure which one you picked from Carvana, but their price range for 2015 Rex is between $14K-16K
I like Carvana. I bought my current Prius C DD from them. But i think their prices on the I3 are a bit high. You can buy 2017 Rex's with 30-40K miles for prices in the 16-17K range. The 2017 might be a better fit for your airport trip
 
It was Carvana.

Yeah, Carvana is hit-and-miss. Have heard complaints of cars supposedly inspected arriving with damage, dirty seats, bald tires, mechanical issues, etc. Carvana also has an extended warranty that covers the car, though some owners have had problems getting their car repaired quickly, depending on where they were at.

i3 owners have had mostly good luck selling their cars to Carvana though.
 
blackbelt said:
Not sure which one you picked from Carvana, but their price range for 2015 Rex is between $14K-16K
I like Carvana. I bought my current Prius C DD from them. But i think their prices on the I3 are a bit high. You can buy 2017 Rex's with 30-40K miles for prices in the 16-17K range. The 2017 might be a better fit for your airport trip

I agree their prices are a little high, but they offered me a very high value on my Miata (they offered almost the same price for it that I paid them for the same car two years ago), which is why I went with them. Physical dealerships were offering over $4K less in trade value. I might just end up selling my Miata, and then trying to find a good deal on a 2017 i3.
 
Miatas are a real easy sell, you should have zero issues selling yours yourself for good money. Carvana actually gave me a decent offer for my Toyota, but it didnt make up for the high price they wanted for the I3. I bought a 2017 Rex with 30K miles on it for under $16K. It did cost me over $1,000 to have it shipped across the country, but it was still a good value. Carvana may still buy your Miata outright, give that a try.
I had pretty good luck using autotrader on line as well as car gurus when i was searching for my I3. Keep your eye on ebay also. A private owner one popped up on there that i just missed and it was a bargain.
 
One way to sell a car like the Miata depending on your price point is on "Bring a Trailer". Cars in good condition can get the price bid up pretty high. I sold an old MGB on the site for 40% more than best offer I could get locally. Here is a page showing the Miata's that have sold on the site.


https://bringatrailer.com/mazda/miata/
 
MKH said:
One way to sell a car like the Miata depending on your price point is on "Bring a Trailer". Cars in good condition can get the price bid up pretty high. I sold an old MGB on the site for 40% more than best offer I could get locally. Here is a page showing the Miata's that have sold on the site.


https://bringatrailer.com/mazda/miata/

Very true! There is a reason that Bring a Trailer is nicknamed "Bring a Trustfund", some of the vehicles on there get bid up to stupid high money. Great for the seller. Downside is that you never know if they will take your vehicle. I tried to list my Nissan Pao on there, and they turned it down. I even offered to go no reserve and they still said no. Really doesn't seem to be much rhyme or reason for the cars they list.
 
Really doesn't seem to be much rhyme or reason for the cars they list.

Yeah - they can be a bit odd with their listing decisions. Their motto is "vintage and classic cars", but have seen a few Honda Elements listed - not something I'd consider either vintage or classic - and talk about crazy money - with a Blue Book trade-in value of $2500 , a 2006 Honda Element sold on Bring a Trailer for $30K, almost $10K more than when it was brand-new..
 
Given the Carvana purchase price was almost what I paid for it in 2018, I took it. No hastle or fuss. Now I just need to find the right deal on an i3!
 
So, found a 2017 REx model with 60k miles for a little less than the 2015 with 55k miles. Hopefully the bigger battery will have more of its capacity, and enough range that even as it degrades it will still serve my needs. It could be a week or two before it gets delivered - I will update when I get it.
 
The 2017 is a keeper. Even with the cold weather, it is getting around 115 Miles on battery, compared to 50 with the 2015. This car has already ruined gas cars for me. My wife's 2020 Honda Odyssey feels crude in comparison.

Jacob
 
grinning said:
The 2017 is a keeper. Even with the cold weather, it is getting around 115 Miles on battery, compared to 50 with the 2015. This car has already ruined gas cars for me. My wife's 2020 Honda Odyssey feels crude in comparison.

Jacob

I second Jacob’s comments. As an owner of both 2015 (60ah) and 2017 (95ah) cars the 2017 is a much more capable car.

I do my best to only burn electrons, but the 2015’s range makes it tougher for longer days.

Once 2019’s are reasonable, I’m going to get rid of 2015.
 
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