Yesterday at EVS29 in Montreal, BMW announced an energy storage system which uses BMW i3 battery packs. The system can utilize a used i3 pack, or it will be able to be purchased with a brand new battery pack. Perhaps the best aspect of the program is the fact that if you own an i3, you can have your old battery pack built into the system when you upgrade your car with a new pack.
I've been waiting for this announcement for a while now. I can remember talking with one of BMW's top program managers from Munich three years ago. We were discussing my home solar system, and how I'd been powering my MINI-E and ActiveE electric cars with clean, renewable energy from the system for many years at that point. He then asked me the question, "What do you think will happen to your EV's battery once it has reached its end of life?" I answered that I would imagine it would probably be taken apart and recycled, with the lithium being used for new batteries. To which he said, "What if I told you when you need a new battery for your car, you'll be able to keep your old pack and put it in your house. You'll then have the ability to store your unused solar energy, and use it to charge your car at night when you get home. That will assure you're driving a true zero emission vehicle all the time." At that point I remember just smiling and he told me: "When you get your i3, I promise you you'll be able to do just that."
BMW displayed a smaller, more stylish energy storage system at CES in Las Vegas earlier this year. It appears as if each layer of this system could hold one module from the i3's battery pack.
That was three or four years ago, so obviously I'm not quoting him verbatim, but that's pretty much exactly how the conversation went. So this program has been in the works for many years now, and hopefully will be launched soon. The press release doesn't specify when the system will be available, or have any hint of pricing. The one thing I really like about this program is that BMW will allow the customer to keep their old battery pack for use in the system when they upgrade their car to a new pack. No other automaker has provided their customers a path for a 2nd life use of their own battery pack. You already paid for it, why not get another 10 years or so of use from it? Plus, it will be a great comeback when people ask sarcastically (and they do ask this), "Where do you think those toxic batteries from your electric car will end up when you need to replace them?" I can now say, "I'll hang them on the wall in my home for home energy storage," and walk away smiling.
“With a battery storage system electrified by BMW i, our customers can take the next step towards a sustainable energy lifestyle. Coupled with the home charging and solar energy programs, the system enables BMW drivers to embrace holistic sustainability beyond e-mobility,” Rob Healey, Manager of EV Infrastructure for BMW North America.
My i3 in front of my home with an 8.775 kW solar array on the roof. I've been powering my electric cars (MINI-E, ActiveE and now i3) with clean, renewable energy since 2010 and would love a system like this to store my excess generation for later use. Having the ability to use my old i3 battery when it's time to replace it would make it even better.
I currently have 52,000 miles on my i3. If I keep the car long term (still undecided on that), I'll probably want a new battery in two to three years when I have about 120,000 miles on the odometer. By then I'm certain BMW of North America will have started the battery upgrade program which is currently only available in Europe. In order for this 2nd life energy storage system to work, BMW would have to allow customers to upgrade their battery packs. Therefore I take this announcement as further evidence that BMW of North America will absolutely participate in BMW's battery upgrade program, even if they decided not to do so just yet.
Although it wasn't mentioned in the press release, I suspect these complete battery packs are stackable. This will allow commercial applications to stack a tower of perhaps ten of them, and store 100 to 150 kWh of energy in a 4' by 6' space. If they were using new 94Ah cells in the pack, it would store over 300 kWh in the same footprint.
This is clearly where the industry is going. Tesla was the first automaker to offer for sale a home energy storage system, and since then other OEMs have announced that they too are exploring this market.
The 2017 i3 comes with 40% more range than the current model. It's also available in a nice new color: Protonic Blue
The worst kept secret of the BMW i3 is officially no longer a "secret". BMW has formally announced that the 2017 i3 will have a new, longer range battery pack. They are indeed using the new Samsung 94 Ah battery cells that I speculated they would five months ago.
Just as I predicted the new battery pack is increasing from 21.6 kWh to 33.4 kWh, which in an increase in capacity of about 50%. However the range of the i3 BEV will only increase by 40% from 81 miles per charge to 114, which is less than i predicted. That's because BMW is now using a larger buffer (the difference between the total battery capacity and the usable capacity) and also because the car now weighs more (roughly 100 lbs more) because the new higher capacity cells weigh slightly more than the ones they replace. The slight increase in weight will likely only have a very minor effect on performance, if any. The old battery used 60 Ah cells and had a capacity of 21.6 kWh, of which 18.8 kWh was usable. Which means BMW allowed the 87% of the capacity to be accessed. The new pack uses 94 Ah cells, has a total capacity of 33.4 kWh, and 27.2 kWh is accessible. That means only 81% of the total new battery capacity will be usable.
The reduction of usable capacity could simply mean BMW just wants to be more conservative, and with more available capacity they didn't need to squeeze every possible kWh out as they did with the much smaller 21.6 kWh pack. Or, quite possibly the new battery cells don't fare as well as the current cells do when they experience frequent deep discharges, so it's necessary to build in a larger buffer.
The new range rating for the REx model hasn't been announced yet, as it is still undergoing official EPA range testing. I have a theory about why this is so, but I'm going to wait until we get the range rating of the new REx before I elaborate. I do expect the REx to have a smaller percentage of range increase than the BEV i3 did, but I'm going to leave it at that for now. I'll dedicate a new post to this subject once the official EPA range for the new i3 REx is announced.
The new Protonic Blue will likely be a popular choice
While the increased range is the biggest news for the 2017 i3, it's not the only changes. The i3 will be available in a new color, Protonic Blue. At the same time the popular Solar orange is being discontinued. So the color options for 2017 on, will be: Fluid Black, Protonic Blue, Capparis White, Mineral Gray, Platinum Silver and Ionic Sliver.
One interesting nugget which was announced in the BMW AG press release, yet not in the US press release was the BMW i battery retrofit program:
"With the introduction of the new 94 Ah battery, BMW gives i customers the opportunity of retrofitting their purely electric BMW i3 (60 Ah) with the new 33 kWh battery as part of a high-voltage retrofit program. This program is available in selected markets. The 22 kWh batteries traded-in by customers are used to build stationary storage battery modules thus starting their second life. This effectively proves how sustainable BMW i technology is across its entire production and life cycle"
This is very exciting news, even if it appears that initially only BEV i3 (not REx) owners will be able to upgrade their battery, and initially at least, the US market won't be able to participate. I'd be very surprised if this upgrade program isn't made available to the US market at some time in the future, but I believe the real question is what will the cost be? I would imaging the entire pack, including the thermal management system and packaging probably costs BMW somewhere between $7,500 and $10,000. If they offer a $3,500 discount for the old pack as a trade in, than the customer's cost is somewhere between $4,000 and $6,500 without adding the cost of labor for swapping the packs. So unless BMW subsidizes a big chunk of the cost it's going to be a very costly upgrade, especially considering the owner is replacing a battery that is less than three years old.
The new 94 Ah Samsung battery cells are the same physical size as the current 60 Ah cells, but they weight slightly more.
I think that's partially why BMW of North America isn't rushing to bring the battery upgrade program here. The i3 just passed its two year anniversary here in the US, so even the earliest buyers still have a relatively new battery. I have one of the highest mileage i3s in the US, and currently have just under 50,000 miles on my car. My battery still has about 18 kWh of usable capacity, after starting with about 19 kWh. So in two years, I've recharged the vehicle about 1,200 times, driven nearly 50,000 miles and my battery has only lost about 5% of its original capacity. I'm definitely not ready to drop $5000 or so on a new battery just to add 30 or 40 miles of range.
I do expect BMW of North America to eventually offer a battery replacement program, but honestly it's just not necessary yet. I could definitely see myself buying the replacement pack in another two years, when I have about 100,000 miles on the car. I'd also be interested in buying back my old pack, once it's been refurbished into the stationary energy storage unit, and using it in my home. My solar array could charge the unit during the day, and when I come home at night I'd use the stored energy to recharge the new pack in my car. I don't know if BMW has plans to make this kind if home energy storage units, but if they did, I'm definitely interested, especially if I could reuse my old battery pack.
Atelier will be called Deca World for the North American market and will be the new base interior trim
The new Dark Walnut wood dash trim
There are also a few interior changes on the new i3. Finally (Let me repeat that!) FINALLY, the US market will be able offered the moonroof option. Much to the chagrin of i3 owners across the country (and particularly the ones in California), until now the moonroof option that was available on the i3 everywhere else in the world, wasn't available in North America. It will now be offered once the 2017 i3 begins shipping sometime in late August. There is also a new interior option being called Deca World (to go along with Mega, T\era & Tera Worlds). Deca World replaces Mega World as the base trim and is an attractive Black fabric with BMW i Blue trim. It has been available in Europe since the i3's launch, where it's called "Atelier". There's also a new dark oak wood option to go with the lighter Eucalyptus wood dash panels. Customers who order other of the two top interior trim levels (Giga or Tera World) will now be able to choose which wood trim they prefer.
BMW's "Born To Go Further" video ad for the 2017 i3
In all it's pretty much what I expected the 2017 i3 would offer. BMW calls this kind to product refresh an LCI (Life Cycle Impulse). That's a mid generation refresh for the vehicle where they make improvements, but don't create a new vehicle. The battery upgrade is the big deal of this LCI, and will probably the biggest improvement the first generation i3 has during its lifespan, which will likely be until about 2019. I expect a totally new 2nd generation i3 to emerge about that time, along with the next generation of batteries that Samsung is still working on. These new future cells are low profile, are 125Ah with a specific energy of about 250Wh/kg. They pack about 33% more energy than the new 94 Ah cells BMW will introduce in the 2017 i3. So while 2017 brings some nice improvements for the i3, the next big leap forward in battery tech is once again only a couple years away. It's not difficult to see how similarly priced EVs will soon attain cost and utility parity with internal combustion engine vehicles. It's all about the batteries.
The i3 is the most efficient production car available today
Every now and then I have a reader send me an article they wrote and ask if I'd like to post it here. Usually it's not exactly what I'm looking for and politely explain why I won't be posting it and thank them for sending it nonetheless. Occasionally I'll get something interesting though, like the post below which was sent to me by Robert Kasper. I think it's particularly timely since just last week I posted the Tesla/BMW comparison piece and I think this is an interesting follow up to it. I hope you enjoy:
Efficiency or Range? You Can’t Have Both.
…But Advanced Technology Can Help.
By Rob Kasper
In the world of electric vehicles, whether Battery Electric Vehicles (BEVs) or Plug-in Hybrid Electric Vehicles (PHEVs), there is a clear trade off between range and efficiency. For a given technology, efficiency suffers as range increases due to the weight of not only additional battery capacity, but the increased structure and volume to haul that capacity around. Now that there are a significant number of plug-in vehicles being manufactured, and a recognized standard to test them, we can identify trends. Consider Table 1 and Figure 1, a plot of efficiency (as measured in EPA MPGe) vs. range in miles for 2014 plug-in electric vehicles measured by the EPA. They are grouped into Battery Electric Vehicles (BEVs) and Plug-in Hybrid Electric Vehicles, and further identified as either conventional or advanced technology design and construction. Conventional technology is generally characterized by a manufacturer’s use of an existing gasoline powered platform modified for battery electric drive, steel frame construction and cladding, and standard battery technology. Advanced technology is generally characterized by a clean sheet, purpose built EV design, extensive use of aluminum or aluminum plus Carbon Fiber Reinforced Plastic (CFRP) for weight savings, higher energy density lithium ion battery packs, with the bonus of performance equivalent to or exceeding the best of conventional technology plug-in vehicles.
Figure 1: Efficiency vs. Range
Table 1: EPA Electric Range and MPGe
Beyond the obvious observation that the price of greater range is lower efficiency within a given technology, it is important to note the significance of advancing technology. The ground-up EV design, significantly lighter weight construction, and advanced battery technology of the BMW i3 and Tesla Model S push the blue trend line significantly up and to the right of conventional BEVs’ green trend line. As significant is the single data point (in purple) representing the only advanced technology PHEV currently available – The BMW i3 REx. Not only is it capable of greater efficiency and far more range than any conventional PHEV (the red trend line), it is more efficient than all but two conventional BEVs, with only slightly less range than all but the most inefficient conventional BEVs.
It is this outlier of a data point, the BMW i3 REx that might best help illustrate why a smart means of increasing the range of an EV may not necessarily be to add more battery capacity. Battery energy is clean and well suited for powering vehicles for relatively short-range transportation but due to its weight and lengthy charge times, inefficient and inconvenient for long distances. On the other hand, the benefits of energy density and convenience make gasoline/diesel energy better suited for longer range transportation with the trade-off being greater well to wheel emissions in many parts of the world. In the case of the BMW i3 REx, each mile of range requires either 0.15 pounds of gasoline, or 5.7 pounds of battery capacity. At 37 times the mass specific energy density of battery power, very little gasoline is required to extend range for a given tank size, and that tank can be replenished in minutes nearly anywhere in the well developed fossil fuel infrastructure that currently exists worldwide. This capability requires a 265 pound increase in the weight3 of the vehicle for the REx engine and associated systems, which imposes a 6% decrease in efficiency, but once set, that efficiency does not appreciably decrease as more energy in the form of gasoline is added to increase range. Increasing battery capacity cannot increase range as efficiently, as not only must the weight of the battery increase by 37 times the weight of gasoline per mile in the first increment, but by the weight of increased structure and volume, as well as even greater battery capacity to offset the reduction in efficiency resulting from the weight increase. There comes a point where the sacrifice in efficiency may no longer be worth the additional range to be gained. See figure 2:
Figure 2: EV Energy Storage (and Generation) Weight vs Range for Advanced Technology EVs
1- EPA testing protocol does not account for approximately 4 miles of range remaining after REx fuel exhaustion when publishing a 72 mile battery powered electric range before REx activation, but does account for it in the total range calculation of 150 miles: 72 electric miles + 1.9 gal x 39 mpg + 4 electric miles = 150 EPA range (76 electric + 74 gasoline). 76 miles of range is also the result of dividing the EPA measured total i3 wall to wheel consumption of 22.0 kWh by the i3 REx EPA measured consumption rate of 0.288 kWh/mile. This value is further corroborated by the CARB BEVx designation awarded to the i3 REx which requires the electric range not only be at least 75 miles, but that it must exceed the gasoline range, neither of which would be possible without accounting for the ~4 miles of range remaining after REx fuel exhaustion.
2- The EPA’s 95 MPGe rating of the Toyota Prius Plug-In Hybrid includes 0.2 gallons of gasoline operation plus 29 kWh of electric operation per 100 miles. Subtracting the 10 mile of gasoline operation contribution to the total (0.2 gal X 50 mpg) yields 29 kWh per 90 miles, or 32.2 kWh per 100 miles, which results in 105 MPGe for electric only operation. (MPGe = 33,705 divided by watt hours per mile.)
3- While EPA rated at 87 miles of range in its base form, purchasers of the Mercedes-Benz B-Class can choose to pay an additional $600 for the Range Package, which makes an additional 17 miles of range available. There is no difference in total battery capacity between the two configurations, only the percentage of SOC made available to the driver.
4- The 8 BMW battery pack modules weigh 55 lbs. each, for a total of 440 lbs. Reference page 17 of the BMW i3 Service Managers Workshop Participant Guide at http://darrenortiz.com/website_pdfs/BMWi3PG.pdf.
5- 265 lbs for the REx engine and all associated equipment is the difference in weight between the i3 BEV and i3 REx as published on BMW’s spec pages: http://www.bmwusa.com/Standard/Content/Vehicles/2014/i3/BMWi3/Features_and_Specs/BMWi3Specifications.aspx http://www.bmwusa.com/Standard/Content/Vehicles/2014/i3/BMWi3RangeExtender/Features_and_Specs/BMWi3RangeExtenderSpecifications.aspx. Adding the 440 lb. battery weight makes the total energy production and storage weight at 76 mile of range 705 lbs. This increases by 11.4 lbs. of gasoline for every 74 miles driven beyond 76.
6- Widely quoted in other sources, Car and Driver claims the Telsa Model S 85 kWh battery pack weighs 1323 lbs: http://www.caranddriver.com/reviews/2013-tesla-model-s-test-review. This is exactly 600 kg, making it appear to be an estimate, but it is the only number we have to work with, as Tesla does not publish the spec.
7- Weight of the 60 kWh Tesla Model S battery pack is estimated from the 85 kWh figure to be 60/85 X 1323 lbs. = 934 lbs.
