Will an Optional "High Power" Battery For the i3 Be Available Soon?

I was tipped off by an anonymous follower here that the Spanish i3 online configurer has a not-yet-available option called "Bateria de mayor potencia" which Google Translate will tell you means "battery more powerful" in English. There isn't a picture for the option and you can't order it - yet. I checked the other BMW models on the site to make sure this wasn't just some kind of phantom option or mistake that was listed on all the BMW cars on the site and it isn't. It was in fact only listed on the i3 options page.

An inside look of  i3 Battery module

So I reached out to a contact I have in Spain that is well connected in the electric vehicle community there to look into this and see what they can uncover. Could the Spanish BMW site have inadvertently tipped us off as to what will soon be available? Maybe this is as innocuous as an optional, more powerful 12v battery? However I've never heard of an optional 12v battery being offered in any i3 market yet and I'm not sure why would they would need it? The 12v battery doesn't need to do very much on the i3 the first place. The car is already equipped with a cold weather package in cold-climate markets and there is no mention of a more powerful battery in that package. I would think if BMW thought the standard 12v battery was insufficient they would have just made all the cars standard with the more powerful one in the first place.

i3 Battery pack

There have been rumors that BMW is already field testing higher density batteries and that they will be available in the not-too-distant future. BMW has always maintained that the i3's battery pack is easily replaceable and that it's likely down the road when a customer determines it's time to replace their pack the replacement pack will be more robust, allowing for a greater range than the original battery did when it was new. Could that be available sooner than we anticipated?

Battery tech is constantly evolving. Tesla for example is rumored to be replacing the current batteries they use with higher density cells in the very near future and will soon open the Gigafactory(s) to manufacture them. Over in the BMW ActiveE Facebook group we recently had a fellow ActiveE driver say he had the opportunity to ride in a test MINI-E at BMW's Technology Center that was fitted with BMW's next generation of batteries and the car had about a 200 mile range. This cannot be confirmed but I have no reason to doubt his claim.

So this may be nothing, a simple mistake or misunderstanding on the BMW i3s Spanish website. Or maybe not...

To REx or Not To REx, That is The Question: Part 2

To REx or Not to REx, that is the question many potential i3 buyers are struggling with now

Back in September of 2011, only 6 months after I started this blog, I wrote a post titled "To REx or Not To REx, That is The Question". At the time, very little was known about the i3, and even less was known about the range extender; other than it would be available as an option and would appear sometime after the initial i3 launch.

The sign at the New York BMW i Born Electric Tour claimed a 100 mile range for the i3. It's looking like the EPA range rating will fall short of that.

My conclusion back then was if the BEV i3 had a real 100 mile range I would probably pass on the REx, but if the range was closer to 80 miles and the REx was only about $3,000, then I would probably go for it, providing I didn't have to wait too long after launch for the REx to be available. As it turned out, my fears about the range were justified. Even though I don't have proof of the EPA range rating yet, I feel confident by now that the range will be less than I had hoped, and that the i3 will have an EPA range rating that is somewhere in the 80s. I drive a lot and that's just cutting it too close for me. At 90-95 miles per charge I could probably do it, realizing that after 2 or 3 years the range will likely be in the high 80s anyway. A 100 mile EPA rating would have absolutely eliminated the need for the REx, but no company outside of Tesla is offering that on a real EV (one that is available across the Country). So at $3,850 the REx is a little higher than I would have liked it to be, but it's not astronomically overpriced, considering the utility value of having it on board and ready when you need it. 

So after bouncing back and forth a few times, I've decided I'll be getting my i3 with the range extender. After about five years of driving pure electric, I'll be back to hauling around an ICE. I don't love the idea, but I'm not hung up on "pure EV" dogma either. The goal is to use less gas and if the range extender allows me to drive on electric the vast majority of the time, yet still have the utility I need on the days I need to drive farther, than the goal is accomplished. The i3 simply won't have the necessary all electric range that's necessary for me personally but that doesn't mean it's not enough for many others. As you can imagine I'm not alone with the struggle to decide which version of the i3 to get. Now that the i3 is available to order in Europe, and only weeks away from being available in the US, I'm reading posts in the i3 forum and in our i3 Facebook group where others are grappling with the decision of if they should go BEV or REx.

I'll try to outline the pros and cons here. If you think I miss something please feel free to add your reasoning in the comments section. Here are my top six reasons for and six reasons against the range extender:

Why go for the range extender:

The added utility. Not having to plan out your mileage or look for public chargepoints if you know you'll be pushing the range on a particular day will be a welcome feature to many people. You won't have to think twice if your plans change and you need to drive more miles than you planned that day, and on days you know you'll be driving far you won't have to use the other family car, borrow a gas car or use a car sharing or rental service. With the exception of extremely long drives (hundreds of miles) that will take you up extended long mountainous routes the i3 with the REx can take you wherever you need to go without worry. Also as the car ages, the battery will lose capacity and your range will shrink. A new i3 with an 85 mile range may only be able to comfortably deliver 75 miles after 3 or 4 years. The REx means the car will always deliver the same utility regardless of how old it is and what shape your battery is in.

No range anxiety. There is some over lap with the first reason, but this really is another issue in itself. There is a difference in not using the car one day because you know the range wouldn't be enough, and miscalculating your total miles because your route had a detour, or your life had a detour that day. It happens. You  can plan your day all you want but things come up and you often need to drive farther than you thought you would have to. Usually the extra range you have is enough to get you home, but there are those days where you just come up short and can't make it. The last few miles you are gripping the steering wheel a little tighter and looking down at your range gauge every minute or so. I've been driving electric for nearly 5 years now and I can honestly say these kinds of issues don't happen often, in fact they are very rare. However when they do happen, it isn't fun. I can remember walking home at 2am last summer and thinking about how great it would have been to have that little REx motorcycle engine on my ActiveE. On that night, I ran out of charge about a quarter mile from my house. What made it really interesting is I live in a very rural area of New Jersey. There are no streetlights on my street and it's really pitch dark at 2am. Add to that I saw a bear walking on my lawn a few weeks earlier so as I was walking home I couldn't help but think of the headline, "EV advocate gets mauled by bear walking home because his electric car ran out of charge." I don't know if that is range anxiety or bear anxiety, but I could have really used the REx that night. I know some would say just get an EV with a bigger battery. No matter how big the battery is there could always be occasions when you miscalculate your range or drive farther than you planned and come up short. The range extender virtually eliminates any range anxiety unless you live in an extremely remote area where there aren't charge points or many gas stations where you drive. If that's the case, perhaps an EV isn't the best choice for you right now anyway.

Resale value. There isn't a lot of empirical data since modern EVs haven't been available long enough to really establish how much a pure EV will depreciate as compared to an EV with a range extender. Now that the earliest LEAF and Volt lessees are beginning to return their cars that were on three year leases, I believe in a year or so we can properly gauge if there is much of a difference. I suspect that electric cars with range extenders will fare much better in the second hand market. I know if I were looking to buy a three year old i3 I'd be much more concerned about the condition of the battery if it didn't have the REx. After three years there will be range degradation, there is no way around it as the battery ages. Will a three year old BEV i3 still have 90% of its original range? How about 85%? We simply don't have the answer yet. That uncertainty really hurts the value of the car. The potential new owner won't really know how far it can go until they buy the car and live with it for a while. However if the used i3 has the REx, then the all electric range isn't nearly as important. The buyer can still do anything they want with the car. They can drive it as far as they want to and the only negative they have is they may use a little more gas than when it was new because of the lower electric range. If it's a pure BEV they also have to worry about how many more years they have with the car until the range really impacts the cars utility - the REx removes that concern. Of course if you lease the car this isn't your problem and one of the reasons I recommend leasing if you are in the market for an EV today.

When will this be commonplace?

Lack of infrastructure. If there were level 2 charging stations in every parking lot, and finding a place to plug in while you work, dine and shop was without hassle, then daily life with a ~80 mile BEV would be simple. If we also had a robust DC quick charge infrastructure then long distance travel would be easy, even if it meant stopping more frequently then you would have to for a gasoline car. However we just aren't there yet. Outside of certain areas of California and a couple other progressive areas, charging infrastructure is still in its infancy. It's going to take a while for EV charging to be ubiquitous. I do believe we'll get there, but not for a while. There will be a lot of growing pains and I believe the number of EV's sold will greatly outpace the number of public charge points installed. For most people outside of a few select areas, I fear finding available EVSE's will be very difficult for the foreseeable future.

My ActiveE battery was frequently drained

Damage from frequent deep discharges. This may be a minor concern, but since the REx will turn on at about 6% state of charge, the battery won't be run down to very deep discharges. There is about 10% buffer when you drain the i3's battery completely so when the REx turns on the real state of charge is actually about 15%. The buffer is there so you don't do really deep discharges which would damage the battery. However I can't help but think if you are a high mileage driver like I am with a BEV i3 and frequently roll into your garage with the state of charge below 5% of the available capacity, the cumulative effect of doing this frequently will have negative effects on the battery. With my MINI-E and ActiveE, there were many times I drained the battery well under 5% and even drove them until they just stopped and wouldn't go any farther a few times. This isn't good for the battery, but since these were test cars that would be taken out of service after two or three years there was really no reason to pamper the battery. However if you shell out $45,000 for a new i3, you will want to take good care of your battery, as it's the most expensive component of the vehicle to replace. Frequent deep discharges can bring on early degradation which will mean less range and perhaps even cause more deep discharges and accelerate the early capacity loss of your pack.  

My ActiveE preconditioning in the snow

Cold weather range degradation. If you live in an area that gets cold during the year this is something you need to be very cognizant of. Even with a sophisticated thermal management system like the i3 has and the ability to precondition the battery and passenger cabin, the range of an electric vehicle is less when it's cold outside. The combination of the need to use energy to power the cabin heater, the seat heaters, the defroster, etc, plus the fact that the batteries simply cannot store and use the same amount of energy as efficiently as they do when it's warm conspire to cut into the range. Without having thoroughly tested the i3 in cold conditions, I still feel confident saying you can expect at least a 20% range reduction in temperatures below freezing, and that number could quite possible as much high as 30%. So lets say the i3 gets an EPA range rating of 85 miles per charge. I wouldn't expect the average driver will get more than 60 - 70 miles per charge when they are driving at or below freezing, and even less as the temperature drops much lower than that. It should be noted that this isn't permanent range degradation, like I was referring to above.  As soon as the temperature rises back up again, so will your range, but that could mean for 3-4 months a year you have to live with an EV will less than 70 miles per charge. With the REx all this means is you may use a little gas, but you won't have to change your driving style, find secondary roads to your destination so you can drive slower or wear a hat and gloves so you don't need to use the cabin heater.

Reasons against getting the REx:

Do you mind if I smoke?

It's an electric car! - You don't want really want to put gas in it do you? The whole reason for going electric is to get away from gas, right? Well there are lots of reasons for going electric while not needing to buy gas anymore is definitely one of the top ones. The way I see it, my goal is to use as little gas as possible. My EVs are mostly powered with electricity generated from my solar array which really makes them as close to true zero emission vehicles as possible. I don't feel bad if I end up burning 10 or 20 gallons of gas in a year with my REx i3, after all I used to use that much gas every four days when I commuted in my SUV. Still an electric car that burns gas can leave a foul taste in your mouth as the exhaust pipe does when the REx is running

This stuff shouldn't pour out of an EV!

ICE complexity means added maintenance. One of the great aspect of electric cars is their simplicity and
extremely low maintenance. Slap an internal combustion engine as a range extender in there and you just complicate things. Now oil changes, tune-ups, filters, mufflers, etc are all part of ongoing maintenance again, just when the electric car promised to put all that in your past. The only redeeming aspect is since you'll likely only use the REx occasionally, the maintenance schedule will not be nearly as intensive as it is on a normal ICE car. Still - this is a major drawback in my opinion.

The added weight of the REx reduces the cars efficiency and performance. The i3 is the most efficient electric vehicle on the road. Everything BMW did while designing it was centered around lower weight and increasing efficiency. The REx adds 265lbs of dead weight to the car, which has to be lugged around everywhere you go. Even if you don't use the REx for a month at a time, every mile you drive you'll be carrying it with you. The efficiency will take a hit and you'll be using slightly more electricity to power the car whenever you drive it. It's kinda like going hiking and carrying 30 water bottles in your back pack every time you hike, even though you usually only need 1 or 2 of them for 95% of your hikes. Plus, the added weight robs some of the performance. The all electric i3 will go 0-60 in about 7.0 seconds, while the REx i3 will need about 7.7 seconds. Still pretty quick, but if you're driving a REx i3 and a BEV i3 pulls next to you at a streetlight, kindly decline the invitation for a race.

It takes a little away from the cool futuristic feel of the car. Driving electric is a blast. It's a different driving experience that most will tell you is actually better than driving ICE. There is also a really cool feeling that you are really driving the future. The ultra silent vibration-less cabin, the instant torque and feeling that you are almost being pulled along by a string instead of the car providing the propulsion really lets you know you are definitely not driving something from a past generation. Add to that the i3's futuristic architecture, advanced electronic features, extensive use of carbon fiber for the passenger cell, aluminum for the frame and thermoplastic for the outer skin and this is indeed a car of the future that you can drive today. Do you really think an internal combustion engine that's vibrating and belching pollutants into the air as you drive along really belongs there? Of course it doesn't.

It will complicate your conversations: I've been driving electric for nearly five years now and I still get people asking me about my cars all the time. I can't go to a car wash without someone asking me about it and often when I return to my car parked in a lot at a shopping center there is someone there looking at it and wanting to ask me about it. With a REx i3 I can no longer say, "Yeah, it's all electric and I love never buying gas!" like I do now. I see the conversation going something like this:

Them: That's an interesting car is it electric?
Me: Thanks, yes it is.
Them: Wow! Cool  - so it's all electric?
Me: Well it's not all electric, but 99% of the time I drive it is all electric. It has a small gas engine that is used to recharge the batteries if I need to drive farther than the electric range will allow.
Them: Oh, so it's a hybrid. My neighbor has a Prius and loves it.
Me: (Groaning under my breath) No, it's an electric car with a range extender.
Them: So it's not like Prius then?
Me: Well it's not like the old Prius, but there is a new Prius now that is a plug in Hybrid and it's kinda like that but has a much greater electric range.
Them: So it's kinda like the plug in Hybrid Prius, but it's not a hybrid you say?
Me: Have a nice day. (Drives off mumbling)

I've driven the i3 a few times now, and the distinctive styling attracts a lot of attention. If you buy an i3 expect a lot of curious people asking you questions about it and the range extender definitely makes explaining the car more difficult.

Cost: The range extender option costs $3,850.00 in the US and that's a lot of coin. There is also the concern that in some states getting the REx option will then disqualify the car for the zero emission tax exemption. If that is the case, the range extender will end up costing them closer to $7,000 because the sales tax will add another $3,500 or so to the price. However I don't think this will be the case because I know BMW has been working very hard behind the scenes to get the i3 REx classified as a zero emission vehicle under the CARB BEVx rule. Hopefully we will get clarity on this soon because I know states like NJ, Washington and Georgia (possibly others also) all have tax exemptions and/or other state incentives for zero emission vehicles, but not plug in hybrids. Still, even if it only costs the $3,850, that is a significant additional cost.

Ultimately you have to decide what best suits your needs. I would hate to have someone buy a BEV i3 and then realize they can't live with the limited range and struggle with worrying about running out of charge. However I also don't want to give the impression that the BEV i3 wouldn't work for a lot of people. I happen to drive much more than the average person. I drive between 33,000 and 35,000 miles per year and average around 85 miles per day so for me the REx i3 makes more sense. However as I've said, I have lived the past 5 years with pure EVs and really didn't have too many instances when I wished I had a range extender. Only you know what's best for you. That reminds me of one of my favorite Dr Seuss quotes: 

“You have brains in your head. You have feet in your shoes. You can steer yourself any direction you choose. You're on your own. And you know what you know. And YOU are the one who'll decide where to go...” 

This one has the REx

You have brains in your head. You have feet in your shoes. You can steer yourself in any direction you choose. You're on your own, and you know what you know. And you are the guy who'll decide where to go.
Read more at http://www.brainyquote.com/quotes/keywords/decide.html#rPcLldjpa2jFvQDb.99

DC Quick Charge: Better Than a Bigger Battery

A BMW i3 charges at the first public SAE CCS quick charge station open in the US. 

The first public DC quick charger in the US that uses the SAE-endorsed Combined Charging System (CCS) opened this week in San Diego, CA. It's located at the Fashion Valley Mall and uses a dual connector quick charger called a "Freedom Station" by EVgo.

The i3 will have a DC quick charge option that the customer can elect or pass on. The price has not been set yet but the speculation is it will cost somewhere between $750 and $1,000 extra. Having the option will allow you to recharge the car to 80% in about 20 minutes. This is an incredible advantage to have in an EV, since charging times are really what limit EVs like the i3 from being able to cover hundreds of miles without much inconvenience. Of course you can get an EV with a huge battery like the Tesla Model S which will allow you to drive a couple hundred miles between charges, but to be able to really cover long distances without much inconvenience, DC quick charge (or battery swap ability) is really needed. 

Standards War

SAE & CHAdeMO side by side

Tesla understands the absolute need for quick charging on pure electric vehicles and is rolling out their own network of DC quick chargers they call Superchargers. Since Tesla uses a proprietary connector nobody other than Tesla customers will be able to use their network. Nissan uses a different connector called CHAdeMO (short for CHArge de MOve or charge for moving) which was developed by Tempco (yeah, the power utility that runs the Fukushima nuclear power plant) for quick charging electric vehicles in Japan. When Nissan came out with the LEAF, the SAE hadn't yet endorsed a DC quick charge connector for the US so Nissan had no other option but to use the CHadeMO connector on the LEAF for quick charging, not that they wouldn't have anyway. Then, once the SAE endorsed the CCS connector, BMW, along with Audi, Chrysler, Daimler, Ford, GM, Porsche all agreed to use it on their plug in vehicles, when they eventually make them. I'm not going to go into why one is better than the other, or why some manufacturers chose one over the other here. There are plenty of articles on the internet that discuss this at nauseam; just do a simple search and you'll find them. I will say that I've talked with a few BMW engineers about this and they all basically told me there was no decision to be made. That the SAE CCS system is so technically superior to CHAdeMO, especially for future applications, that they wouldn't have even considered it. 

Personally, I really don't care which "standard" my EV has, as long as there are chargers out there for me to use. I've held both and even plugged both into cars and the SAE is a little lighter and less bulky and you only need a single charge port on the car so I tend to favor it, but honestly, I would be fine using CHAdeMO if there were chargers installed in my area and there aren't. At the i3 premier in July a BMW program manager asked me how much would I be willing to pay for the DC quick charge option. I suspect the price for the US market hadn't been finalized yet. My response was, "That depends" eliciting his curiosity. I followed it up by saying right now I won't pay a penny for a DC quick charge option because there are no chargers within driving distance of my home. However let's say there were a couple here and there in my general area, then I'd pay about $500 for it. And if there were a couple dozen of them in northern New Jersey I'd be willing to pay $1,000 for it. 

 
I know we are many years from having DC quick chargers in accessible, convenient locations like gas stations but I also believe that day will eventually come. The West Coast has a huge head start over the rest of the country and probably has as much as 70% of the Superchargers, ChadeMO and now CCS stations installed in the entire country. Plus, with the recent NRG settlement California will get 200 more DC quick charge stations, most being dual connector (CHAdeMO and CCS) units. Tesla currently has 24 Superchargers installed and an aggressive plan to cover the rest of the US in a few years. Nissan meanwhile has committed to installing hundreds of CHAdeMO stations in the US although they haven't delivered much on that promise yet. Outside of California's NRG settlement the future is unclear how and when we'll get the SAE CCS stations installed. Without any clear plan for the area you live in, I think it would be foolish to pay up to $1,000 for the option if you don't even know if you'll ever be able to use it. I have a friend that bought a LEAF in 2011 here in New Jersey and paid for the CHAdeMO option but nearly three years later he has never been able to use a CHAdeMO station because there are none within his range. 

I had the opportunity to talk with a BMW manager at the i3 premier about DC Quick charge infrastructure and one of the questions I asked was will the BMW i dealerships be required to install a DC quick charge station. I thought that would be a great way to at least begin the roll out of compatible DC quick chargers for the i3 so customers will at least have their local dealerships to fill up quickly at. They could also look for BMW i dealerships along the route of their long trips and since most dealerships are on highways, the locations would probably be good ones. Unfortunately that isn't going to happen. The dealers will not be required to install DC quick charge stations, but they will be "encouraged to." Personally I'd like to see BMW "encourage" them by offering to supply them with the DC charging station for free, as long as they pay to install, maintain it and have it available for use even when the dealership is closed. The dealerships will however be required to install multiple level 2 charging stations though which is a start, but really doesn't help out with longer road trips.

"Quick" Level 2 Charging

Is there such a thing as quick level 2 charging? While level 2 charging (240v) isn't necessarily quick, some cars do charge quicker than others. The Model S is the king (in the US at least) of L2 charging as it can charge at a rate of up to 20kW with optional dual onboard 10kW chargers. However the real L2 charging champ is only available in Europe. The Renault ZOE's onboard "Chameleon charger" can charge at up to 43kWs! On the other end of the spectrum is the Chevy Volt that is restricted to 3.3kW charging. However since the Volt has a much smaller battery than a Model S, it can actually fully charge in about the same time as a Model S can with it's massive 85kWh battery. The i3 will be able to charge at up to 7.4kW, and since it has only a 22kWh battery, it can fully charge in under 3 hours. This delivers a rate of about 30 miles of range per hour when charging from a 240v 30 amp level 2 charging station. That's a good improvement from my ActiveE, which returns only 15-18 miles of charge per hour. BMW is quick to point out how fast the i3's battery can be replenished while charging on L2, and while it is better than any non-Tesla EV here in the US, it still pales compared to the 80 miles of range you can get in 20 minutes on a DC quick charger.

Bigger battery vs DC quick charge 

The i3's 22kWh battery will allow for 80-100 miles or range in every day driving conditions, and up to 125 miles if the more efficient ECO-Pro+ driving mode is selected (Says BMW). So if range is so important, why not just slap a 40kWh battery in there and call it a day? The i3 would get about 200 miles of range and you wouldn't need quick charge, right? Wrong. Tesla uses enormous battery packs and they still realize they need a DC quick charge network to really make their electric cars viable to the broad public. Even with 200 to 300 mile range their customers want to be able to quickly recharge so they can drive long distances. The truth is, no matter how big your battery is and how far you can drive on a single charge, people will always want more range and quick charging. This is way BMW is offering the range extender on the i3. They know that it's going to take years for a comprehensive DC quick charge network to be built out, so until we have a robust infrastructure in place, the range extender will be a very popular option and will allow the owner to drive as far as they need on the few occasions they need to travel long distances. For daily use they won't use any gas, as the ~100 mile range should be more than enough for the vast majority of the time, yet they still have the flexibility of being able to cover hundreds of miles should the need arise. I believe the range extender becomes obsolete once we have adequate quick charge infrastructure in place. In fact, large Tesla-sized batteries won't be necessary either. Why carry the additional weight around and pay for a huge battery pack when you can use one half the size and just charge it quickly when the occasional need arises? The main reason EVs cost more than conventional powered vehicles is the cost of the battery pack. A smaller pack combined with readily available quick charge is clearly the way to go, however getting the infrastructure in place is the 800 lb gorilla in the room. It's not just going to happen without the support of the manufacturers. Tesla and Nissan seem to be doing their part, will BMW and the others that have signed up to use the SAE CCS standard do their part? Only time will tell.
 

The BMW EV infrastructure team was well represented at the grand opening event for the first public CCS quick charging station. Will they continue to be involved in assisting CCS station deployment, or wait by the sideline and watch?

BMW i3 REx: A Hobbled Horse or a Galloping Thoroughbred?

The BMW i3 range extender engine which is made by Taiwanese manufacturer Kymco for BMW.

There is still a lot of unknown information about the i3. BMW has been extremely conservative about what information they offer. While they have stated it will have an electric range of 80 to 100 miles and cost about the same as a nicely equipped 3-Series, the two biggest questions still remain: What will the EPA range rating be and exactly what will it cost? However right behind those two questions for many people is: What will the performance be when the range extender is in use?

The range extender engine will be a 650cc Kymco engine borrowed from the BMW C650 GT scooter. It will be highly optimized to lower noise & vibration and will only put out 35hp, compared to its 65hp when used for the scooter. The gas tank will be a miniscule 2.8 gallons and BMW has stated it will extend the range of the car about another 90 miles, effectively doubling the cars range. However many journalists are wondering will that added 90 miles be an ultimate driving experience or the ultimate disappointment?

The REx will fit nicely next to the e-motor

The Chevy Volt is the closest vehicle to compare the REX i3 to, even though it's not exactly an apples to apples comparison. The Volt has a 1.4 liter gas engine that puts out 80hp to power the generator, more than double the output of the i3's gas range extender engine. However the Volt weighs 1,000lbs more than the i3 will and isn't nearly as efficient so it would naturally need a larger, more powerful range extender engine. The Volt's robust range extender allows it to drive uninhibited while the range extender is maintaining the car's charge. The million dollar question is will the same be said about the i3? That answer looks like it will be no, it won't. BMW's Product and Technology Communications spokesman, Dave Buchko said of the range extender: "The i3 range extender is meant to enable the car to go a little further than the pure BEV on those rare occasions when driver needs to go a little further. It is not intended for daily use. We've said that the REx [range extender] will double the effective range of 80-100 miles. I have not seen anything to suggest that it would not be capable of doing so.". Then BMW North American CEO Ludwig Willisch said while the range extender is running: "The car will not be as agile," Willisch said. "It will not have full power when it runs on the combination."

I'm not exactly sure what "not intended for daily use" means though. That sounds like you'll break if you use it every day and that's obviously not going to be the case. Will the cars performance be so inhibited while in REx mode you wouldn't want to drive it that way every day? I find it difficult to believe BMW would add the range extender if it was so weak it offered terrible performance while in use. Willisch must have confidence it will perform admirably in REx mode though because he predicted at least 80% of US i3 buyers will order it with the range extender. I've also heard it described by some as a "limp home mode" by some(not BMW people) and I also don't believe that is accurate either.

An i3 with the range extender was caught at a gas station refueling in this spy photo. The gas filler door will be located on the front passenger quarter panel and the charge port will be on the rear passenger side quarter panel, just above the wheel.

A big determination of how it will perform in range extender mode is how much of the battery the car holds as a buffer when the range extender turns on. Lets say the i3 normally only uses 90% of its 22kWh capacity. That means the all electric i3 will utilize about 19.8kWh's. If the REx i3 holds another 10% as a buffer to help with short bursts of needed energy than the range extender will turn on after using only 17.6kWh's of the 22kWh pack. This will allow the car to perform better when in REx mode but it will also mean the car will drive about 10 miles less on electricity. The larger the buffer the better the REx performance but the shorter all electric range. I hope BMW allows you to turn off the REx for those times when you could make your destination on pure electricity if you only need a few miles after the REx would have turned on. That way you could utilize the full ~19.8kWh that a BEV i3 has available, without reserving the buffer needed for the REx since you don't intend to need it. Of course the percentages of the battery pack utilization I'm using here are just guesses on my part, but I expect them to be pretty close to reality.

My guess is it will be pretty much in between the hobbled horse and "ultimate driving EV" when the range extender is in use. I think it will drive fine on flat terrain, and can probably even drive along at 70mph in those circumstances. However introduce an extended incline or times when you need to go 75 or more to keep up with traffic and the car could quickly find itself gasping for enough energy to maintain its motion. It definitely won't be a "It'll get you home but you'll have to crawl along at 30mph" but lets just say you'd lose if you try to autocross in REx mode. Then again, if BMW does reserve a fair amount of the battery back as a buffer, it could perform very well for the first 20 miles or so, before the stored energy gets to a minimum and the REx is working at maximum output to sustain the charge level.

The bottom line is if you really just want the security of knowing you'll never have to call a tow truck to get home, then the REx will be worth its weight in gold for you. I've been there on the side of the road a couple times in the past four years falling short of my destination so I know it will be a valuable asset for those circumstances. However if you plan to use the range extender to drive hundreds of highway miles to make a far off destination, then I'm guessing this isn't the right EV for you. Horses for courses. Hopefully, we'll get the answers to these questions and all the technical specifications of the i3 soon. It launches in Europe in the fall so the wait is nearly over.