BMW i3 Range Extender

[BeamerFan]

I was recently reading the full BMW i3 press release and came across this interesting note:

"Range extender increases the driving range. As the MINI E field trial demonstrated, over 90 per cent of the mobility requirements of the MINI E field trial participants could be met with the range of the MINI E. However, some customers want a longer driving range, or want their vehicle to be as flexible as possible. The BMW i3 Concept therefore offers an optional range extender, the REx, which allows the driving range to be increased. REx, a small, very smooth-running and quiet petrol engine, drives a generator which maintains the battery charge level to ensure that the vehicle can continue to run on electric power."

Whats a petrol engine consist of? Would the BMW i3 be still be considered an all electric car with the range extender added?

 

[TomMoloughney]

I was recently reading the full BMW i3 press release and came across this interesting note:

"Range extender increases the driving range. As the MINI E field trial demonstrated, over 90 per cent of the mobility requirements of the MINI E field trial participants could be met with the range of the MINI E. However, some customers want a longer driving range, or want their vehicle to be as flexible as possible. The BMW i3 Concept therefore offers an optional range extender, the REx, which allows the driving range to be increased. REx, a small, very smooth-running and quiet petrol engine, drives a generator which maintains the battery charge level to ensure that the vehicle can continue to run on electric power."

Whats a petrol engine consist of? Would the BMW i3 be still be considered an all electric car with the range extender added?

The base i3 will be all electric, but for those that want the convenience of having the range extender, you will be able to order it as an option. It's rumored to be a 600cc motorcycle engine with a small gas tank (only about 2 gallons). It will operate like a volt where after you use up your all electric range the range extender will turn on and allow you to continue by charging the batteries. Unlike the volt, the range extender will have no physical connection to the wheels, it will only maintain the cars charge so you can continue driving. It's also rumored that the car *may* be in a reduced power mode when the REx is on, meaning it may not have the same 93mph top speed and will have slower acceleration, but that isn't confirmed. I don't have any information on the cost of the REx option, but I will post as soon as I do.

 

[marta]

This wouldn't happen to be a diesel range extender would it? I know BMW has talked about other diesel hybrids recently, I think it would be cool to see a small diesel engine as the range extender.

Edit: I see it says a 600cc motorcycle engine - don't know of any diesel motorcycles!

 

[TomMoloughney]

This wouldn't happen to be a diesel range extender would it? I know BMW has talked about other diesel hybrids recently, I think it would be cool to see a small diesel engine as the range extender.

Edit: I see it says a 600cc motorcycle engine - don't know of any diesel motorcycles!

No, not a diesel. Very efficient gas engine with a very small gas tank (2-3gal) so as not to add too much weight.

 

[carcrazy01]

So BMW i3 is more of BMW hybrid car than a BMW electric car. Anyways, i think its great to have an alternate option.

 

[TomMoloughney]

So BMW i3 is more of BMW hybrid car than a BMW electric car. Anyways, i think its great to have an alternate option.

Actually it's much more of an electric car than it is a hybrid, however it depends how you buy it. The standard i3 will be pure electric, not a hybrid. If you want more range, you can order it (probably for a couple thousand dollars more) with a small gasoline range extender. So after depleting the batteries charge, the gas range extender will turn on and charge the batteries so you can continue to drive.

This is called a plug in hybrid electric car, or PHEV. The gas engine will serve as an instrument to charge the batteries, not power the wheels. The car will still have the 80 to 100 mile pure electric range so one would probably not use the range extender engine too much, but some people want it there for emergencies or for the rare days they need to drive far and cannot charge midday.

 

[klaus]

Hi Tom, I know it's still a ways off from the BMW i3 being available, but I'm curious if you have any details on the range extender option?

Will the range extender re-charge the batteries or will it power the electric motor which will allow you to drive farther, but not re-charge the batteries?

 

[keijidosha]

REx would make more sense in i version of X3, where added cargo space and range would be complementry. I woud take i3 with more battery (30kWh) over REx.

 

[TomMoloughney]

Hi Tom, I know it's still a ways off from the BMW i3 being available, but I'm curious if you have any details on the range extender option?

Will the range extender re-charge the batteries or will it power the electric motor which will allow you to drive farther, but not re-charge the batteries?

Good question. The range extender (REx) will serve only as a generator to maintain the battery charge enough to allow the car to continue driving. It will not 'recharge' the battery pack. Also, it will have no physical connection to the drive wheels like a Volt has, it's really a pure generator. You really wouldn't want it to recharge the battery pack. You don't want to burn gas to charge your batteries, it's a very inefficient way to charge. You really want the REx to run as little as possible, just to get you to your destination where you plug in.

 

[TomMoloughney]

REx would make more sense in i version of X3, where added cargo space and range would be complementry. I woud take i3 with more battery (30kWh) over REx.

I agree. I have suggested an optional extra 5-6kWh to BMW many times. It doesn't look like they are going to move in that direction though. A 28kWh i3 would probably deliver about 125 miles per charge without having to hypermile. I suspect it would be very similar in range to a 40kW Model S.

 

[Conrad]

So still the BMW i3 is still a pure electric vehicle. Even with the range extender, one wouldn't actually say that it is hybrid because the small gasoline engine is a power generator to keep the car going for more miles. I think this is the best concept of an electric car and we all can't wait for the units to be ready for sale!

 

[TomMoloughney]

So still the BMW i3 is still a pure electric vehicle. Even with the range extender, one wouldn't actually say that it is hybrid because the small gasoline engine is a power generator to keep the car going for more miles. I think this is the best concept of an electric car and we all can't wait for the units to be ready for sale!

Conrad: Once you add a gasoline(or diesel) engine to an electric car it's no longer a 'pure' electric car, it becomes a plug in hybrid (PHEV) like a Volt or Fisker Karma. So the basic i3 is a pure electric vehicle but you can order it as a PHEV by getting the range extender option that BMW calls the REx option.

 

[Parker]

Things maybe different in other parts of the world, but here in the UK not all BMW dealers will be i dealers. Only 26 or so (so I'm told) will get the cars...... remember we are only a third of the size of Texas. With regard to the Rex version, my understanding is the Rex option will be just that.....an option, it won't be a specific model you'll just tick a box on the order sheet (if you want it) & your car will come with it. I was also told that Rex will be available from the start. I have seen the i3 twice now but am still not sure how big it is. I think it may surprise a few people with how much room inside there is.

 

[surfingslovak]

I have seen the i3 twice now but am still not sure how big it is. I think it may surprise a few people with how much room inside there is.

We have a good discussion going on the LEAF forum, and lot of this data has been gathered there. Please allow me to repost some of that information here. If the numbers are correct, the i3 will be very similar to the LEAF in terms of its outside dimensions. It will be a bit shorter though. The i3 Coupe, which is said to have interior similar to the production version, was stunning. I had an opportunity to see the Coupe concept at the LA auto show, along with other electronauts. A friend of mine said that the design will likely end up in the Museum of Modern Art. Size-wise, the interior is supposed to be close to the 3 series.

i3 Coupé:
--------
156" long
69" wide
61" tall

LEAF
--------
175" long
70" wide 
61" tall

ActiveE:
--------
172" long
69" wide
56" tall

MINI-E
--------
146" long
66" wide
55" tall

Several of us have been exchanging thoughts on the REx option off-list. Power output was one of the chief concerns, followed by noise, heat and emission compliance. Based on the earlier rumors, I assumed that it could be a Rotax engine from BRP, which supplies the engines for BMW's F650 and F850 bikes as well. The performance and displacement figures would be in line with the numbers that have been thrown around. Although they could certainly put out a purpose-built motor for the i3 as well. BRP has three-cylinder engines in their product lineup as well.

http://www.youtube.com/watch?v=pXkaDKACUwU

 

[brg2290]

Two questions come to mind regarding the range extender option for the i3.

Will the REx will be available as a dealer installed option? I live in Washington state, which currently has a generous tax incentive for BEV's only ($0 state sales tax vs. >8% of purchase price for ICE and PHEV). This means there is no state tax on the purchase of a Nissan Leaf, Mitsubishi i, Ford Focus EV or a any Tesla. But PHEV's like the Volt, C-Max Energi, etc. pay the full + 8% state tax. If there's a dealer installed option for the i3 REx, a Wash. state resident could conceivably purchase the car as a BEV, pay no sales tax, and elect to install the REx later.

My second question is, how much might the use of climate controls (heater/defrost) cut into the range of the i3? Maybe some of the BMW E leasee's can comment on how efficient the heating system is in these cars as an indicator of what can be expected when used in the i3. For cold northern climates, the REx option may be desirable simply to allow the car's occupants to stay comfortable while still maintaining a functional range. (This question is generated from seeing the use of climate controls on my 2012 Leaf eat into available driving range)

Gary

 

[surfingslovak]

Hi Gary, it's good to see you here. Thanks for the question, hopefully the LEAF lease is working out well for you. I'm probably not the most qualified person to provide answers about winter driving, since we rarely have temperatures below freezing where I live. That said, based on the discussions in our FB group, it would appear that the ActiveE is as sensitive to range reduction in cold weather as the LEAF was. With one caveat: preconditioning seems to help greatly. I suspect that this is when the TMS shines, since it can heat the battery directly and more aggressively than what we are used to from the LEAF.

I'm not very familiar with the launch plans for the i3, but given the amount of R&D effort going into it, I would be surprised if it came to market with a resistive heater. I would expect a heat pump, much like the one announced for the 2013 LEAF. We tested its operation at the Town Hall meeting in Phoenix, and it would only draw about 1.2 kW when blasting 90-degree air. To be fair, ambient temps were in the high 50s when we were looking at the prototype. A heat pump, combined with heated seats and a heated steering wheel should help reduce energy consumption in winter, and preconditioning should keep the battery warm in the morning before driving off.

The range extender is a very interesting topic, and as Tom mentioned earlier, not much information has transpired from BMW about this. If you haven't seen it already, please have a look at an article by Anton Wahlman. Anton is an EV enthusiast, investor and a Volt driver. He was able to unearth some information about an upcoming new CARB rule for electric vehicles. He goes on to say that if the extended range of a vehicle was less than its pure EV range, then it would qualify as an EV, and not a plugin-hybrid. This would be a big boon, and could help the adoption of EVs. Quick charging infrastructure is starting to get better, but having a small range extender would go a long way to ease the buying public into this new paradigm.

 

[brg2290]

Hi Gary, it's good to see you here. Thanks for the question, hopefully the LEAF lease is working out well for you. I'm probably not the most qualified person to provide answers about winter driving, since we rarely have temperatures below freezing where I live. That said, based on the discussions in our FB group, it would appear that the ActiveE is as sensitive to range reduction in cold weather as the LEAF was. With one caveat: preconditioning seems to help greatly. I suspect that this is when the TMS shines, since it can heat the battery directly and more aggressively than what we are used to from the LEAF.

Thanks for your reply George. So far, so good on the Leaf. As a matter of fact, I'm kind of glad my first experiences have been in mid-winter, worst case scenarios (of course other than having new car, full battery capacity), since the experience / range should only get better with warmer weather and decresed use of climate control. While I'm unable to access the FB group info. as I'm not on FB, I get the gist of what you're saying here.

...I would be surprised if it came to market with a resistive heater. I would expect a heat pump, much like the one announced for the 2013 LEAF. We tested its operation at the Town Hall meeting in Phoenix, and it would only draw about 1.2 kW when blasting 90-degree air. To be fair, ambient temps were in the high 50s when we were looking at the prototype.

I like this improvement, but I wonder how effective the heat pump system is when heat is needed most. My understanding is that heat pumps lose much of their efficiency in sub-freezing temps. BTW, I followed the buildup to and reports from the Phoenix meeting. Thanks for being there to represent owners and be a witness to Nissan.

If you haven't seen it already, please have a look at an article by Anton Wahlman. Anton is an EV enthusiast, investor and a Volt driver. He was able to unearth some information about an upcoming new CARB rule for electric vehicles. He goes on to say that if the extended range of a vehicle was less than its pure EV range, then it would qualify as an EV, and not a plugin-hybrid. This would be a big boon, and could help the adoption of EVs. Quick charging infrastructure is starting to get better, but having a small range extender would go a long way to ease the buying public into this new paradigm.

Thanks for this. I like this approach, and it makes sense to me. The REx might be even more important than QC, as it's functionally close to carrying a QC on board. While the QC infrastructure may be building out where you are, it's nowhere to be seen in Eastern Washington. I know Washington state has a (largely deserved) reputation for being EV friendly, but most of the resources and the scope of the EV Project are I-5 corridor / western Washington centric. The REx would work for us folks out here in the hinterlands. (I actually considered a Volt for this very reason, but chose the Leaf because a) the lease terms made it somewhat financially justifiable, b) I didn't want to be maintaining two integral drive systems and c) I wanted to see if a pure EV would meet my typical transportation needs - so far it has.)

Gary

 

[TomMoloughney]

Two questions come to mind regarding the range extender option for the i3.

Will the REx will be available as a dealer installed option? I live in Washington state, which currently has a generous tax incentive for BEV's only ($0 state sales tax vs. >8% of purchase price for ICE and PHEV). This means there is no state tax on the purchase of a Nissan Leaf, Mitsubishi i, Ford Focus EV or a any Tesla. But PHEV's like the Volt, C-Max Energi, etc. pay the full + 8% state tax. If there's a dealer installed option for the i3 REx, a Wash. state resident could conceivably purchase the car as a BEV, pay no sales tax, and elect to install the REx later.

My second question is, how much might the use of climate controls (heater/defrost) cut into the range of the i3? Maybe some of the BMW E leasee's can comment on how efficient the heating system is in these cars as an indicator of what can be expected when used in the i3. For cold northern climates, the REx option may be desirable simply to allow the car's occupants to stay comfortable while still maintaining a functional range. (This question is generated from seeing the use of climate controls on my 2012 Leaf eat into available driving range)

Gary

Hi Gary,

I can't imagine the REx would be available as an add on option. To begin with there isn't a fuel filler hatch on the BEV i3 so you would need to do extensive body work just to open up a filler port. I don't think you'll be able to get around that tax issue if you really want the REx option, I'm afraid.

As for the climate control, it wouldn't really be of any value to compare the ActiveE to the i3. I doubt they are even using the same climate control components. The heater in the i3 definitely uses a fair amount of energy, I would hope the i3 heating system is improved some, however it is better than it was in the MINI-E which had a terribly inefficient heater.

Sorry I can't be of more help. It shouldn't be too ling before we start getting more technical details on the i3.

 

[Northwestern]

With regards to the REX, I think it's a great idea for no other reason than I don't think it is safe to be hanging around a super-charger station for 30 minutes at 9 p.m. at night. In any event, costs matter and if the i3 w/REX is going to sell it must be priced accordingly. Any thoughts about the tail pipe? How is it routed? I didn't see a tail pipe even on the spy shots of an i3 filling up at a gas station (therefore it has a REX).

BTW, a used BMW 650 Rotax engine sells for about $1,200 on ebay. Add the gas tank, cat converter/tail pipe, fuel hoses, connectors, etc. and the costs add up fast. I would think BMW might want to sell the REX at cost to move the other 93% of the car.

Thanks for hosting the forum! I saw the i3 "in the wild" at the LA auto show last month and I really liked it.

 

[TomMoloughney]

With regards to the REX, I think it's a great idea for no other reason than I don't think it is safe to be hanging around a super-charger station for 30 minutes at 9 p.m. at night. In any event, costs matter and if the i3 w/REX is going to sell it must be priced accordingly. Any thoughts about the tail pipe? How is it routed? I didn't see a tail pipe even on the spy shots of an i3 filling up at a gas station (therefore it has a REX).

BTW, a used BMW 650 Rotax engine sells for about $1,200 on ebay. Add the gas tank, cat converter/tail pipe, fuel hoses, connectors, etc. and the costs add up fast. I would think BMW might want to sell the REX at cost to move the other 93% of the car.

Thanks for hosting the forum! I saw the i3 "in the wild" at the LA auto show last month and I really liked it.

I was told they have carefully placed the tailpipe so that it is not visible by someone walking by or driving behind. I'm curious where it is also.