Informative Comparison Test On Updated 2017 BMW i3 94Ah (33 kWh): Performance, Charging

10 months ago by Warren M 62

Freshly minted 2017 BMW i3 94 Ah (with 33 kWh battery) and original flavor BMW i3 (60 Ah/22 kWh battery)

Freshly minted 2017 BMW i3 94 Ah (with 33 kWh battery) and original flavor BMW i3 (60 Ah/22 kWh battery)

Several months ago, I ordered my 2017 33kWh i3 BEV, and just picked it up just this week. Outside of the range extender, the car is basically fully loaded with every option.  I am still against having any gas capability, and have been fully electric for over 4 years now, (starting with my 2012 LEAF), but can see why many would find comfort in picking the range extender version. Window sticker for my BEV was $53,345 (image below).

Even after all this time, I still feel the i3 is in a different class when it comes to interior quality, I really appreciate the leather dash stitching and dark oak wood dash of the 2017 Terra i3.

Interior of the BMW i3 (shown here in Terra) show a definitely level of refinement not commonly found in most all-electric vehicles today

Interior of the BMW i3 (shown here in Terra) show a definitely level of refinement not commonly found in most all-electric vehicles today

One of my biggest concerns was that the heavier newer 33kWh i3 would be much slower than my 22kWh i3 BEV. That car is pretty quick, clocking 0-60 in the 6.4-6.5 second range. I recently had the factory programming update, and was fearful that it would diminish the older i3’s acceleration numbers.

Thankfully, I am happy to report that today’s test numbers in the original car are identical 6.4-6.5 numbers from 0-60mph as they were before the software update.

Video (below): Impromptu ‘wet test’ of the BMW i3

The 2017 94Ah i3 on the other hand feels a little less sharp in acceleration response. But feelings aren’t always representative of reality, so I proceeded to put the test gear (Vbox) in the 2017 model for some comparison runs (see above video).

While the 2017 is measurably slower, I am happy to report it is only by about .10-.15 seconds slower 0-60 mph. This car runs 0-60mph in the 6.5-6.6 second range vs 6.4-6.5 seconds of the 2014 model. Not a huge difference.

Video (below): Quick 0-60 mph performance run between the BMW i3 and Chevy Spark EV

2017 BMW i3 Monroney/window sticker (click to enlarge)

2017 BMW i3 Monroney/window sticker (click to enlarge)

One of the biggest advantages of the 94Ah i3 is how they changed the charging taper on it. The larger battery can sustain a significantly higher charge rate even when starting at a higher SOC.

With both vehicles starting at roughly the same SOC (42.5%-%44%), in 30 minutes the 2014 i3 packed in 9.18 kWh. vs 17.14 kWh for the 2017. And significantly, even at 92% vs 82%  SOC for the 2014, when I started an extra 10 minute session, I found the 2017 was still charging at a 70% faster rate.  Above 98-99% the 2017 showed at least another 12 minutes left, but that is pretty close to being fully charged anyways and way faster than the 60Ah i3 98% SOC rate.

BMW i3 charging comparison between battery options

BMW i3 charging comparison between battery options

There has been discussion about the much vaunted no taper DC CCS charging of the Chevy Spark. Luckily I was able to take an identical road trip with a new Chevy Spark and did side by side charging time comparisons with my older i3.

Time for a quick test with the Chevrolet Spark EV

Time for a quick test with the Chevrolet Spark EV

Yes, as expected,  the Spark had the faster charging times with less taper. The predicted time to charge the 22kWh i3 from 24% to 80% was 25 minutes. The predicted time to charge the Spark from 27% to 80% was only 13 minutes. Almost twice as quick!

When the Spark hit 100% charge in just under 28 minutes, the i3 was at 88% and had an hour to go to reach 100%  So one would think that the Spark is putting at least twice as much charge in its battery as the i3 in the same time, and that is where you would be dead wrong.

Truth of the matter is with both cars starting at mid 20% SOC, by the time the Spark was fully charged just under 28 minutes, its 12.70 kWh gained was only a slim .75kWh greater than that gained by my 60Ah i3. Amazingly the 94Ah i3 in same 30 minutes puts down 17kWh+ even starting at 42.5%. Something the older Spark and older i3 in the chart below can’t come close to.

Some more data - BMW i3 and Chevy Spark EV

Some more data – BMW i3 and Chevy Spark EV

The i3 has already been around for 3 years, so I am really looking forward to the new Sport model due out perhaps within this next year. I am hoping it will have greater acceleration and more autonomous driving features to distance itself from its immediate competitors once again. The cars unique design principles and the way the i3 effortlessly zips around town with rock steady stability while accelerating is more important to me than hauling around a bigger/heavier battery at this point in time.

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62 responses to "Informative Comparison Test On Updated 2017 BMW i3 94Ah (33 kWh): Performance, Charging"

  1. SparkEV says:

    Was the test using different chargers? Photo seem to show that. I find some DCFC to be slower than others, some as low as 35 kW even when they are same brand and model (ABB).

    People generally charge to 80% before taper become severe. With high taper, cost goes up, sometimes as low as 2 MPG gas car, so it’s prudent to disconnect at “just enough”, which is about 80%. Of course, those who get free charging would plug in for entire 30 minutes even if they’re charging at 1 kW using DCFC.

    Then it’s better to compare power up to 80%, assuming that’s when i3 starts taper.

    For 2016 SparkEV, 9.29 kWh to 80% in 14 minutes is 39.8 kW on average, bit on low side for SparkEV. I measured that to 90%.

    33 kWh i3: 17 kWh to 62% in 30 minutes, average of 34 kW. 12.35 kWh to 79% in 20 minutes is average of 37 kW. That’s pretty close to SparkEV to 90%, but lagging to 80%. Since different charger may have been used, it’s bit suspect, though.

    22 KWh i3: 14.26 kWh to 79% in 30 minutes is 28.52 kW on average. 7.61 kWh in 20 minutes to 76% is 22.83 kW on average. That’s significantly lower than SparkEV, and borderline Leaf territory. Was there some error?

    1. SparkEV says:

      Another for 22 kWh i3 is 10.39 kWh to 80% in 19 minutes for 32.3 kW on average. That’s more like it, but still lower than what I thought i3 might do (ie, more than 36 kW on average, 0.1 kWh in 10 seconds). Charger problem?

      1. Warren says:

        It absolutely has to do with the starting SOC, as the i3 probably begins to taper around 75% or so, the Spark EV does not. Bottom line is that the i3 really tapers above 75-80%, but in absolute kWh gained when starting from the same 24-27% SOC, the amounts are very similar in the given time frames.

        The charging test vs the Spark was as close as it could be. We both took off from the same city and reset our trip odometers. So both cars had the same miles on them before charging, under similar ambient temps, speeds, etc. The total kWh picked up in the same amount of time was very similar. What was not similar was the “predicted” time to charge to 100% as the BMW tapers way off. So this begs the question: If the top off kWh to 100% is pretty small to wait such a long time, perhaps there is some benefit on longevity that this gives the i3 over the Spark in the long term? That is the question we may never know the answer to. However, one would have to admit the unique air conditioned battery of the i3 would allow for superior temperature control.

        But for practical purposes, under many scenarios, the i3 will pick up similar kWh in similar time. You can see the 2 instances where the i3 picked up about 11kWh in 20 minutes on different days, different chargers when starting at the 11%-25% SOC. Similar to the Spark.

        Keep in mind, this is the 2016 Spark which uses different batteries than your 2014. I think A-1 vs LGs? The 2016 Spark EV is also quicker. I have a video of the 2014 Spark vs i3 and it was a slaughter. On the other hand, from 60-80mph, the 2014 Spark EV was just was fast as the 2016 Spark EV.

        The only major aberration here is that the 2017 94Ah i3 was very slow in charging from 9% SOC in the first 10 minutes. It only picked up 4.77kWh. Yet it did 5.91kWh in the first 10 minutes when starting at a higher state of charge! (42.5% vs 9%). This is the opposite of what is normal. And this is most likely due to the fact that the session on the 94Ah i3 starting at 9% SOC was in very cold ambient temps (39F). So that may have made a difference. But you can see how it caught up and passed the 60Ah i3 by the time 30 minutes had elapsed which is even more impressive. The new i3 definitely has much more practical charging characteristics, that is for sure.

        1. SparkEV says:

          I’m driving 2015 SparkEV, which is pretty much the same as 2016.

          About 25 kW on average to 75% with 22 kWh i3 seems way too slow, so that’s why I ask if there’s charger problem. In one case, it did 32 kW to 80%, so ~25kW to similar level seems way too low. If i3 starts taper about 70%, that could explain 32 kW average, but not 25 kW.

          If the average power is about 36kW to 70% (or 80%), we’re talking about only few minutes slower than SparkEV. But at ~25 kW, that’s approaching double the time. Indeed, I don’t think I ever went over 20 minutes at DCFC (other than stuck in line at market and letting it go way over), mostly just 15 minutes to get to 80% even if I start at low SoC.

          As for cooling, I think SparkEV (and Volt) between cell liquid cooling is superior in terms of moving heat. But for weight savings, i3 “freon cooling” might be better. That could explain why SparkEV could charge at higher power longer.

          As for battery life, mine now shows bit over 18 kWh from supposedly 18.4 kWh new, 97.8% after 1.75 years. This is after many hundreds of DCFC and running it down really low. I think the battery is doing fine even with high rate of DCFC.

          1. Warren says:

            You have me scared, because I actually run my battery down to almost 0 miles quite often (.5% the other day!). And I quick charge pretty much exclusively.

            So I checked my capacity:

            19.6 kWh at 8862 miles 4/2016

            19.6 kWh at 17534 miles 1/2017 today.

            so 0% degradation showing on the diagnostic cluster screen in over 8600 miles.

            One thing to remember is that liquid cooling doesn’t get your battery pack below ambient temps. So if it is 100F outside, you literally have hot air/water trying to cool off your battery. Refrigerant on the other hand can chill your battery temps as needed. The BMW system can handle higher temps more quickly in high ambient temps because of the higher temperature differential it can generate with the a/c compressor.

            1. SparkEV says:

              SparkEV liquid cooling would get it below ambient temperature by using AC. This is why SparkEV manual explicitly state that it should be plugged in when ambient is too hot. If cooling doesn’t get below ambient, there’d be no point in plugging in when hot. In fact, it’d be counter productive to plug in when hot since charging will make even more heat.

              2015 SparkEV cools with plates between cells, so it would cool quicker than smaller contact area of i3. I think i3 has bottom plate and cell-to-cell spacing is not cooled, much like 2014 SparkEV, though with freon.

              As for degradation, I’ve only been monitoring for about 4 months. It needs full charge so I can plot the data for most accuracy (ie, minimize rounding errors), and I rarely charge to 100%. In those 4 months, there’s been no degradation at all. Unfortunately, I don’t have a base line so I have to assume it was 18.4 kWh when new, not 18 kWh that Tony Williams measured. Either way, I think degradation is minor even with all the DCFC with TMS cars like i3 and SparkEV.

              1. Warren says:

                The A123 battery used a coolant plate below the cells. It also used Dexron in the coolant system. That is merely antifreeze, not refrigerant like the i3.

                Are you sure the LG pack in the 2015+ Spark EVs are really refrigerant cooled by the AC system like the i3? My Focus EV tells me to plug it in while in hot weather, but it doesn’t have a AC system cooled battery pack either.

                1. SparkEV says:

                  I meant 2014 SparkEV use plate like i3, but i3 uses freon cooling while 2014 SparkEV uses liquid. My wording was poor.

                  All SparkEV are Dexron cooled, but that Dexron is also cooled by AC to become less than ambient temperature (and heater to become above ambient). It may not be the most efficient arrangement from energy point of view, but they move heck of a lot more heat due to much larger heat capacity of liquid compared to gas. In case of 2015+, they also have much larger surface area that coolant flows through.

                  As for TMS, they would all be using AC/heat even if they use liquid. There’s no point in just having radiator like gas cars since EV don’t produce nearly enough heat for system like that to have much effect; everything would reach ambient, and it’d be just like having no TMS at all.

                  1. WARREN says:

                    Do you have a link to any diagrams or technical data showing how the AC compressor integrates into the battery cooling system of the SpArk EV?

                    1. SparkEV says:

                      I don’t have a diagram, but George Bower might know where to get one. This forum discussion is for Volt, but I suspect SparkEV is similar in principle, though maybe different in implementation.


                    2. Unpluged says:

                      The Focus Electric stole (borrowed?) the same cooling system as the Spark and Volt. This makes sense, as the same LG batteries are used in the Focus Electric, and Ford wanted to use the Volt battery testing, rather than start all over. In any case the Focus Electric uses coolant that is refrigerated by the A/C system to cool the battery.

                      This A/C cooling is best demonstrated when the Focus Electric is turned off, and a warning comes up on the dash in temperatures over 100 degrees: “It is hot outside. Plug in when possible.”

  2. William says:

    At $ 53K MSRP, the 2017 BMW I 3 (33kWh) is going to have to be compared to a preowned 2013-14 Tesla Model S. At around $50K, the Tesla sure doesn’t supercharge or accelerate slowly.

    1. Michael Will says:

      Or a new Tesla Model 3 for $15k less, or a new S60 for $20k more, both with seats for 5 adults and luggage, fast supercharging, 5 star safety, and options that go way beyond what BMW can offer.

      1. DonC says:

        It’s a known fact that imaginary cars are always better than real cars.

      2. TL says:

        I agree… who would buy this car if you can have a new Tesla Model S for $15K more or a used Tesla for $15K less?

    2. Warren says:

      Apples to Apples. You can also pick up a Certified- Pre-owned i3 with a 100,000 mile, 6yr warranty in the low $20K range, just as a happy used i3 owner had profiled in a previous story on this forum.

      And it also depends on what you want. Technically you aren’t supposed to be using the superchargers around your home town. So if you are charging in your garage, you have a lot more time and energy used to fully charge a big Tesla battery vs an i3 battery.

      Besides energy usage, and environmental consciousness in which the i3 excels, it is also a more practical car to use around the city. I absolutely prefer the i3 with its superior parking maneuverability, and turning radius (Think U-turns on just about any street), compared to a larger Tesla size sedan. Especially since 90% of the time I am carrying 2 people or less in my car.

      So yes, I lust after the speed of a Tesla. But the i3 is still away above average in most any traffic scenario. And IF the i3 was just as fast as the Tesla, I would absolutely pick it as my daily driver. It is a configuration that fits my needs more than a car the size of a Tesla. But different people have different needs and preferences, and rarely does one size fit all.

      As far as supercharger locations. In the five closest cities to me, only one has the supercharger. (Oxnard). So I would have to drive to a different city to use it. In the other closest cities (Ventura, Oxnard, Camarillo, Thousand Oaks), they ALL have CCS chargers. So at the moment, they are much more conveniently located. If you drive though the San Fernando Valley, the have EVgo Freedom stations in Calabasas, Woodland Hills, Reseda, etc. All along the 101 corridor. The Superchargers locations are no where near as convenient. They are superior for the long range trips though between the big cities.

      1. John in AA says:

        There’s seldom need for local high speed charging with a large-capacity battery car, making many of these points moot.

        I do agree the large size of the Model S is not always an advantage.

  3. John Hansen says:

    “but can see why many would find comfort in picking the range extender”

    It astounds me that the author of this article can still pretend that a short range EVs are suitable for everyone. I’ve taken two trips in the past week that would be impossible in this car. Meeting bare minimum requirements is not “comforting”, it’s “sane”. It’s fine if this car works for you, and you never have to travel more than 100 miles in the cold, but please stop pretending that it works for everyone! Bring on the long range (usable) EVs!

    1. alohart says:

      I’ve read the article a couple of times to try to understand how you could interpret the author as “pretend[ing] that a short range EVs are suitable for everyone”, but I come to the opposite conclusion. The author clearly states that a short-range EV has worked for him for the past 4 years, but nowhere does he state or pretend that it would work for everyone. In fact, he clearly understands that it wouldn’t.

      Even the Bolt’s 60 kWh battery pack isn’t very usable for long-range travel for anyone other than an EV enthusiast because of poor aerodynamics, an insufficient maximum DCFC charging rate, and insufficient DCFC charging infrastructure (insufficient power and coverage).

      I agree with the need to bring on long-range EV’s, but I would add “affordable” to their description. The only truly long-range, mostly usable EV’s are Tesla’s (if one doesn’t need to wander too far from Interstate highways), but they’re not affordable and they’re too large and heavy because battery cell energy density is still too low and cost is too high. But this is changing.

    2. Warren says:

      Food for thought. The i3 with a range extender is already approaching 200 miles combined range. So “if” 100 AER miles isn’t enough for 95% of your daily driving needs that is a no brainer. There are very few people who need over 100 miles of range that the i3 offers on a daily basis. Just about any 2017 irex driver is achieving over 100 miles, even on the highway. The readout typically shows over 120 miles of AER fully charged.

      So lets say you need to go about 280 miles on a particular trip. Now you are going to have to stop somewhere to charge your Chevy Bolt or typical Tesla. And if you don’t have the DCQC option on the Bolt, then it will be for quite a long while. And if you drive the Tesla and aren’t by a Supercharger, you too will be waiting for hours waiting for a charge at a L2. And if there isn’t any chargers on your way to your destination, you might just be SOL, or waiting a day on a L1 emergency charge! Quite often you will find yourself driving additional miles just to get to that “needed” charger. All the while the i3 takes a 3 minute stop at the gas station to make this happen. A gas station which is probably 300% more likely to find on your direct path to your destination than a charging station will be.

      So I am firm believer the i3 is just an update away to achieving 150 miles AER/ 150 miles Gas or 300 mile combined. You can believe what you want, but I think most people would have less range anxiety knowing that they can find fuel anywhere and yet go over double the distance of a Volt on electricity.

      After realizing that my 94Ah battery will take over an hour to fully charge, and the Bolt 2 hours!, I can see that a range extender for those rare long trips makes much more sense if practical, long range capability is your priority. For me, 100-120 miles of AER and the current CCS infrastructure is just fine. However, my next i3 sport model I am looking forward to replace my Focus EV, may just end up being an irex, IF there are no compromises in performance and acceleration.

    3. MaartenV-nl says:

      John, we are the exception.
      Most people travel seldom (or never) more than 100 Miles a day.
      This is not a car for you or me, but for the other >90% it is perfect. If they are willing to spill the money for it.

      1. mx says:

        True, the vast population of the US is in or near urban centers.

    4. mx says:

      Here’s the thing.
      Say, you have a Used Prius and are going to buy the i3.
      Don’t sell the Prius. Problem solved.
      Since you’ll almost never be driving the used Prius, you will qualify for a lower insurance rate.

  4. georgeS says:

    Thanks for taking the time to write the article Warren. Enjoy your new i3!!

  5. georgeS says:


    Just a suggestion

    I think a plot of charging rate (in MPH) is more meaningful than % charge.

    Failing that perhaps kw.

    1. Warren says:

      Well mph can vary depending on how efficient you drive. Kind of like at a gas pump, it is probably more common to see how many gallons you pumped rather than how many miles you gained when comparing fueling rates. But on average, you get 3.5-4.0 miles per kWh pretty safely. So with about 18.5kWh usable on my 60Ah, that would equate to about 65-74 miles usually. Although I drove home 90 miles from Anaheim Stadium on 18kWh or about 5 miles per kWh, but with stop and go, and slow freeway traffic, that was not the norm.

      But averaging about 5-6kWh per 10 minutes is about 20-24 miles per 10 minutes. Ir 60-72 miles in 30 minutes.

      1. georgeS says:

        “Well mph can vary depending on how efficient you drive.”

        so can kw’s and % charge.

        The only number that matters to the general consumer is MPH and as a Model S owner I agree.

        Next to: “how far will it go”, “How fast does it charge” is the second asked question every one asks.

        Failing that KW’s is the second best.

        1. SparkEV says:

          MPH is the worst metric when it comes to charging. Depending on weather, climate settings, driving speed, same kW power could be different by almost 50%. While % could be different to MFR to MFR (ie, is it GID as in Leaf or total state of charge?), it is closer than MPH.

          Best, of course, is average power in kW since peak power can be misleading with high taper Tesla.

        2. DonC says:

          MPH may work better for the same or similar model, and definitely better for your model, but kWh works better between models. Not sure why you say this is second best. Agree that average kWh would be better than peak but it’s difficult to compare since there are so many variables.

          Also don’t think it matters a great deal. LOL

          1. georgeS says:

            “MPH may work better for the same or similar model,”

            It works best across all models. % charge only works within one model car of similar range.

            The beauty is it encompasses both car efficiency AND charging rate. For a given power charger if you have a more efficient car you get more MPH.

            1. SparkEV says:

              If you’re driving the same road and same time, what you say is true and MPH works. But if it’s for different road with more/less traffic that makes your average speed different, that will also change mi/kWh. Depending on how different the road is, MPH could be off by 50% (or more!)

              kW would be the same for all MFR under all conditions. You just have to add the additional highly variable mi/kWh into the mix to get accurate number. You’re essentially separating charging (kW) from driver (mi/kWh) by doing so.

  6. Janesh says:

    Enjoy your new i3 and regards from the netherlands.
    I also love my 60 Ah 2015 i3 rex which i bought 11 month old, 6000 km, MSRP 52000 euro for 32000 euro.

    1. Warren says:

      Yup, the i3 was one of the top selling cars there, and people in the Netherlands know a thing or two about EV adoption.

  7. Apkungen says:

    Rex is still very useful even for the most hardcore enthusiasts. There are way to often problems with the fast charging stations or a big head wind decreases range substantially or snow and rain do. Charging can fail all of a sudden too. Rex is needed today, no doubt about it.

    1. georgeS says:

      “There are way to often problems with the fast charging stations or a big head wind decreases range substantially or snow and rain do. Charging can fail all of a sudden too. Rex is needed today, no doubt about it.”

      I’ve used many super charger stations and I’ve never had one be down. CCS and Chademo public chargers are a different story. They have a very high “not available” problem.

      1. DonC says:

        Having to wait an hour in line just to start charging doesn’t qualify as being down, but it sure is inconvenient. We’ve seen plenty of videos of congestion, this being one over the holidays:

        Obviously Tesla is aware of the problem — the new charges for not moving after completing a charge show that — but it still hasn’t figured out that you can never provide enough of a free good.

        Basically charging electric vehicles is, at this point, still painfully slow.

        1. georgeS says:

          “Having to wait an hour in line just to start charging doesn’t qualify as being down”

          Ive never had to wait an hour.

        2. georgeS says:

          “Basically charging electric vehicles is, at this point, still painfully slow.”

          My S charges as around 344 MPH at the begining of the charge. That’s pretty decent.

          If you are just having to top off then it’s perfect and soon tesla will double their charging rate.

        3. Larry says:

          If this is for real, I can’t believe the twelfth car in line has any hope of getting a charge before sundown!

    2. Warren says:

      As I said, right now charging infrastructure has been “sufficient.” Partly because there seems to be more and more EvGo Freedom stations popping up in Southern California every few months. But you are right, there is starting to be a greater chance of arriving at an occupied charging station which wasn’t a problem just a year ago.

      That is why I am keeping an open mind in the future when an irex may become a possibility. It is exactly high volume cars such as the Bolt that will make this congestion much worse. Can you imagine arriving at a station and waiting almost 2 hrs for a Bolt to fully charge?? 100% BEVs owners will definitely be suffering more and more range anxiety as charger congestion becomes more prevalent.

      So at this point, there is no other 100 mile AER car out there with a back up engine to get you out of a bind. This is what makes the i3 irex potentially more practical than these other 100% BEV long AER vehicles with their heavy batteries.

      1. SparkEV says:

        Even a year ago, I was encountering many, many occupied DCFC spots, mostly by those who get free charging with Leaf. Oddly, I didn’t encounter many with i3 even though they also give free charging.

        Even now, I suspect those who make you wait at DCFC are locals who get free charging. Without free charging, most waits won’t happen, and we have decent infrastructure in SoCal.

        Free charging SUCKS the life out of EV drivers by making them wait needlessly!

  8. peakay says:

    Hi there, can you comment on your typical range per charge, typical non hypermiling miles per kWh and what the usable kWh range is? I’ve seen a good article on the rex version but not the Bev. Thanks!

    1. Warren says:

      I haven’t had the car long enough to know exactly what the longest range will be in this car. Even though the BEV is rated a full 17 miles or so more than the irex, I find that hard to believe. People with the irex typically get between 100-120 miles, even though the EPA rating is only 97 miles.

      But electric range varies so much depending on your driving habits. The highest I got on my 60Ah i3 was 90 miles out of probably 18.5kWh. (19.6kWh is the current indicated capacity). I will say that the 94Ah has a full 10 more kWh of usable battery capacity.(around 29.8 kWh vs 19.63 kWh). So I would say in the best case scenario if I wear able to go 90 miles on 18.5 kWh, I should be able to go at least another 40 miles or 130 miles total under ideal conditions. I just don’t think the extra weight affects the range as much as you would think. When I did a side by side test with a irex, I only averaged around .10-.20 mi/kWh better than the heavier irex. Virtually the same efficiency.
      Either way, I think I should be able to get an easy 120 miles of range on my new i3 BEV.

      Kind of funny how BMW is so conservative with their EPA and 0-60 numbers now. Along with the quirky styling, you would swear they are trying to keep people from buying this car.

  9. Mike I. says:

    Another car in the same league as those mentioned in this story is the VW e-Golf. I have a 2015 e-Golf and did some testing with the same ABB SAE Combo chargers. In a single 30 minute session, I was able to go from 13% SOC to 93% SOC adding 15.4 kWh. That is more energy added than either the original i3 or the Spark. Also, putting a little effort into making some charts would make the story much more interesting. I did that with my e-Golf data.

    You can read about my e-Golf fast charging tests on the e-Golf forum here:

    I also tested with the BTC chargers that are limited to 100 amps DC.

    1. Mike I. says:

      I should also note that the bigger the battery is, the more kWh you can get in a 30 minute charging session. You can see that with the 33kWh i3, you can add about 17kWh in those 30 minutes. My RAV4 EV with JdeMO can add about 19kWh in 30 minutes because it can take 125 amps for the full duration without any charge tapering. That is purely due to the fact that it has a battery of more than 40kWh total capacity.

      1. Warren says:

        Hi Mike, absolutely right on the bigger battery capacity in regards to charging rate taper. All the chargers that I used in all my charts were the ABB units. It seems that a rate of about 6kWh per 10 minutes is pretty optimal from a speed perspective. In an i3 that is about 24 miles per 10 minutes. You can see that the Spark and i3 are pretty much doing that at the 10 minute and 20 minute marks. Just about reaching 12kWh in 20 minutes. The next 10 minutes is where the 60Ah i3 is slowing down to 14.26kWh total in 30 minutes because it is almost at 80% SOC. I have seen as high as 14.90 kWh in a 30 minute charge starting at a lower SOC, and warmer temps.
        So not too far off of your 30 minute session of 15.4 kWh in your eGolf.

        I believe you said in your testing that your usable battery capacity is just above 22kWh. (Your gross capacity is 24kWh?) That is a full 2kWh bigger than the 60Ah i3. With that extra capacity, I am sure the i3 wouldn’t start tapering so early in a 30 minute session and would most likely also hit that 15.4 kWh that you did in the eGolf. Soon as it warms up some, I will test the 60Ah again from a low state of charge and see how close it is to 15kWh in a 30 minute session.

        As far as the RAV4 gaining 19kWh in 30 minutes, I think the 94Ah i3 will do close to that. At least 18kWh for sure, considering it did 17.13kWh in 30 minutes starting at a 43% SOC and ending up at 92% SOC during that period.

        I am really curious about what the new eGolf and 30kWh LEAF do as far as charge taper. Both of those cars don’t have a refrigerated cooling system for their battery like the i3 does, so they may be a little more inconsistent in warmer temps or repeated charging in short periods of time.

    2. SparkEV says:

      Your plot shows eGolf to be less than SparkEV. SparkEV is almost 40 kW to 80% in this article and hover 45 kW in my tests, but your plot shows maybe 36 kW for eGolf. That would be quicker (or comparable) to new i3 with bigger battery, but definitely not quicker than SparkEV.

      But I must say, I am impressed with eGolf. Despite lacking TMS like Leaf, it does quite well. But I wouldn’t keep it plugged in at hot weather if I have eGolf.

      1. Warren says:

        So I tested tonight in warmer 50 degrees temperatures and a lower starting SOC. I also charged at a different mall this time, in case the Premium Outlet charger was on the slower side.

        I figured I could also gain 15.4 kWh like the eGolf with its bigger battery, if I started at a lower SOC. The 60Ah i3 actually exceeded the 15.4 kWh target in 30 minutes with a 16.69kWh result. And up to 72% or 20 minutes, you can see the i3 is averaging a healthy 42kWh charge rate.

      2. Mike I. says:

        At low SOC, the charger’s current is the limiting factor. I think the ABB chargers are limited to 120 amps DC, but my data above indicates something closer to 110 amps. Since it is limited by current, the battery pack voltage is what determines the kW delivered. The e-Golf has a 360 VDC max voltage as you can see in my charts. I’m pretty sure the i3 and the Spark have higher voltage packs, so they take more kW from the same charger.

        Also, the temperature issues are significant. My data was taken in a best case scenario where the battery was at 1/8 SOC and had sat overnight in 60 F weather prior to charging. Freeway driving and prior fast charging will heat up the e-Golf battery and the car will limit the charging rate to avoid overheating the battery. This can be severe since the pack has no active cooling. I sincerely hope that VW has fitted an active cooling system to the larger pack coming in the 2017 model, but I’ve not heard anything either way on that issue.

        1. Warren says:

          Absolutely makes sense. Interesting how we both went up almost exactly 80%. Mine from 3.5% to 84% vs your 13% to 93%, yet your yield was 15.4kWh vs my 16.7kWh, even though your battery capacity is about 10% larger to being with! Just shows how these calculations might not be as accurate as one might hope.

  10. ModernMarvelFan says:

    Nice detailed write up.

    Thanks for the information!

    Congratulation on the nice new ride!

  11. Sun says:

    I i read the BMW starts to tapers by 65%. This is consistent with my observations in general.

    Please please , do not compare the i3 with Tesla.

    U can possibly compare the engineering , but as to the software U cannot.

    The software is like compare a simple software in motorola flip phone ( with added bugs) to a iphone.

    They are 8 years of difference

    I own a i3 , and i feel BMW not only did not invest in developing software , but did not even do a QA.

    The car insist on showing odometer when plugged in instead of showing the SOC

    The self parking will fail 75% of times. The auto cruise will get u killed.

    Pls , do not compare. One is a car, the other is a computer

    1. Warren says:

      “The vehicle insists on showing the odometer instead of the SOC?” Are you sure you know how to operate the cluster options from the turn signal switch button? Mine shows SOC if I want it to. And besides, the granulated bar graph shows you enough charging resolution without the SOC % displayed anyways.

      I have used my auto parking several times, it never failed, but parks so close to the curb (within 1/2 inch), that I’m afraid it will scratch my wheels.

      The ACC cruise control is awesome. I use it on the highway and around town. Unlike the Lexus which drops operation below 27mph, the BMW will actually come to a stop if the car in front of you does. Yes, it probably won’t slam on the brakes as hard as possible, but it gives you audible warnings if you need to intervene. The only flaw is in detecting cars trying to cut in front of you from the side, I fear it might not detect them soon enough as it tries to follow the car in front. Just an assumption mind you.

      These systems are aids and are not fool proof at this point. And if you think the Tesla system is fool proof, you are really jeopardizing your own safety, and that of others.

  12. Sun says:

    If u mean to say ,EACH TIME , when u plug in your car, flip the button 7 times , to see SOC as user friendly (if I want it to) , then I am wrong , and u r correct.

    Its not “if” , its like “Please flip 7 times , each time”

    Not sure, if u do not know , what user experience is. or u never experienced it.

    Also if u can compare the granulated bar graph without any numbers to a SOC of any modern alliance with exact % of SOC , then again …

    Please read reviews about parking or the fact that i3 does not recognize Dodge cars from rare

    Yes I ma sure u will wait for 1 year for next firmware upgrade , by physically giving the car to BMW –lol


    1. Warren says:

      I usually have my SOC displayed while I am in the car waiting for the DCQC to finish. I don’t usually leave the car unattended while fast charging. If you are outside the car and unlock it with the remote, the bar graph and ETA are large enough to read even from the passenger side window. If you are away from the car, why not use the BMW app on your smart phone to check the SOC?

      As far as OTA updates, BMW definitely has the technology to do it, as they can already contact your car at anytime and let you know what services you are due for, what faults the car has stored, etc. They just don’t want the liability of a vehicle being hacked and compromising your safety. Can you imagine sitting in your car and having the windows and doors lock by themselves, and then the car accelerates full speed into a wall? Say it can’t happen? They were just talking this morning on ABC about pacemakers being able to be hacked. This hacking is becoming a life and death situation. By allowing OTA software changes to your car, you are inherently more vulnerable to hacking.

      1. Sun says:

        First lesson on security
        By OTA , every other manufacturer of every device on earth to fixes bugs , including security vulnerabilities
        This includes cars , phones and u name it
        Not sure why u think otherwise.

        I guess your opinion will change once BMW will introduce that after a few years

        I also like your statement ” BMW definitely has the technology to do it”

        Can u name a company which does not have this most common technology ?

        Like Chrysler has the technology to make very durable cars , but they dont.
        BMW has the tech for OTA , but they dont.
        VW has the tech for making clean diesel cars , but they dont. So people should appreciate VW ?

        Also , i dont have that fancy remote. and i do not want to use my mobile to see SOC. I use it for emails, while i charge.

        1. Warren says:

          BMW often has whole vehicle software updates. If you don’t understand why they don’t want to make it OTA at this time due to security risks, then so be it. Talk about Chrysler, there was a video of one of their products being hacked and driven into a wall or something. So when you are waiting for your experimental OTA software to be security proofed, people can actually be killed from these hacks.

          I use my smart phone to control my TV even. I’m sorry it is too much trouble for you to use it to check your car’s SOC, or its not easy enough for you to see the four charge bars and easily figure out your SOC within a reasonable amount of accuracy.

          I would venture to guess that you are the only one on this forum that thinks that figuring out your SOC is difficult on an i3 while charging.

  13. Alan Drake says:

    Your review confirms that there is no advantage to me to buying a 94 Ah i3. Outside of hurricane evacuation and very occasional out of town trips, I can go months without needing more than 12 mile round trip range. But in a hurricane evacuation, 110 miles is inadequate (try recharging at few road side stations when EVs grow to 0.1% of vehicles !)

    So I am waiting for prices for 2014 i3 with range extender to drop to $15k to $18k. Hopefully in another 9 months.

  14. John Higgins says:

    I’m not sure why the big fuss about the i3 entering into 2017. The car is lightyears away from the range of 200 plus miles the new chevrolet bolt has and is even slower than the previous year it replaces. I think its silly that BMW can be easily outdone in acceleration and range by GM. How about the author compare the 2017 bolt to the 2017 i3 and not to the 2014 chevrolet spark EV. Then their wouldn’t be much to talk about anymore I suppose.

    1. Warren says:

      Perhaps you didn’t understand the emphasis that the i3 is one of the only small EVs with RWD besides the iMiev and Smart car. And of course the i3 handily outperforms those 2 EVs in range, acceleration, etc. I outlined the fact that almost all premium cars are RWD or AWD. A RWD i3 should also have a tighter turning radius than the Bolt. The Bolt is FWD like most other econo-boxes. The interior quality is typical GM econo-box hard plastic. Not innovative materials or design like the i3. Like I said, I was almost tempted to get the Bolt, but really, FWD killed it for me. And you talk about the huge deal of having 200_ miles compared to 100 miles. Like I said, if you must drive long trips, the 238 mile range is still going to give you range anxiety, especially when you may be charging up to 2 hrs. Lets say you had to go 425 miles from LA to the Bay Area. Even the i3 Irex will make the trip faster than Bolt which will have to charge for much longer than the i3 making four 5 minute gas stops. And if you have to wait for an available charger, forget about making the trip on time. And for your daily commute, hopefully it is less than 100 miles!

      And about the Chevy Spark. I don’t think you have your facts straight. The Spark was refreshed in 2015. Different battery, motor, gear box, etc. The car tested was a new 2016. Not a 2014. The Chevy Spark is still and standout performer, hence the comparison.

  15. unlucky says:

    Thanks for going through the trouble of getting data.

    The taper seems mostly due to the battery capacity to me, not any kind of strategic or chemical change. Not that that’s a bad thing.

    This does show that a car with a large battery and a charger with high current capability are critical to getting the fastest fill at the low SoCs. And active cooling helps too, as you see lacking on a LEAF or e-Golf.