BMW i3 Range Extender Designed Mainly as Emergency-Use Unit


BMW i3 Gets Its First Journalist Test Drives In Sweden...Doubt the Range Extender was in Use

BMW i3 Gets Its First Journalist Test Drives In Sweden…Doubt the Range Extender was in Use

Hmm...Hope the Range Extender Doesn't Need to Kick In

Hmm…Hope the Range Extender Doesn’t Need to Kick In

There’s been quite a bit of chatter related to the optional range-extending engine in the upcoming BMW i3.

For example, who builds it?  The answer to that seems to be BMW motorcycle engine supplier KYMCO, a Taiwan-based company that currently has a supply deal with BMW for G450X Enduro motorcycle engines.

But more of the chatter has been related to the usefulness of the optional range-extending engine.  Does it operate in a similar way as the unit in the Chevy Volt?  No, it’s simply not powerful enough to.  Instead, BMW sees the optional range extender as emergency-use unit in those rare occasions when drivers deplete the i3’s battery pack within miles of the nearest charging station.

In essence, the range extender will assist in getting drivers safely off the road and to the nearest charger.  It’s not capable of assisting to propel the i3 with vigor for hundreds of miles, as is the case in the Chevy Volt.  Think of the BMW i3’s range extender as insurance that you’ll make it to the nearest charging station and the picture becomes clear.

David Buchko, BMW advanced powertrain and heritage communications, confirmed this by telling AutoblogGreen:

“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.”

Range for the BMW i3 is expected to be 75-100 miles, according to European tests.  The range extender should bump total range to approximately 200 miles, but again it’s not be assumed that you’ll enjoy BMW-level performance when the battery is depleted and the range extender is forced to kick in.   Furthermore, don’t expect to routinely drive the i3 200 miles in between charges.  It’s not designed to operate in that way.

via AutoblogGreen, Automotive News Europe

Categories: BMW

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9 Comments on "BMW i3 Range Extender Designed Mainly as Emergency-Use Unit"

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Brilliant! and with onboard 6.6kW level II and DC quick charging most owners with the ReX option will rarely use it.

Well, DC quick charging most people won’t use because they won’t have chargers to use them with 😉

Exactly…it’s a backup for more range if needed. But 70-100 miles daily should be good.

I know it has been said before, but I really hope there’s a way to kick the REx on early. For example, I set out on what I know is a 200 mile trip – I want to start the REx right away just to slow the depletion of my battery, rather than drive 100 miles as an EV, and then slog the next 100 miles because the REx can only put out 10-20kW (or whatever it happens to be).

Sounds like that’s not the plan, though I don’t know why it wouldn’t be.

That same type of behavior is what some want out the Volt. We call it “mountain mode light” or “hold mode light”

The car will hold a good battery % in reserve when the REx goes on so you don’t have to worry. Probably as much as 20-25% so you won’t have to worry about slogging 🙂

A PHEV in charge sustaining mode still needs enough power from the ICE to meet the continuous or average power required by the vehicle. 20-30 kW is just not going to be enough for normal vehicle performance in *many* situations. Some people will be slogging.

Even the Volt’s 55 kW generator is not enough to climb Eisenhower Pass at 70 mph. Consequentially, GM provides mountain mode for this situation.

However 20-30 kW will be enough to manage city traffic at normal speeds for a few miles to the nearest charging station.

Personally I prefer the Volt’s design, since it can do anything a gas car can do, including traveling cross country.


That does make a lot of sense. They should definitely have that as an option.

I like that BMW, How much?