BMW releases important software update for i3 electric car

New programming is designed to fix a glitch Consumer Reports found when testing

Last updated: March 25, 2015 02:00 PM

The BMW i3 earned one of the highest scores of any electric car when we tested it. But it gave us a few disconcerting moments when we were driving it this past fall. Fortunately, a software fix became available on March 10.

The i3 is an electric car with an electric motor that puts out 127 kW (170-hp), and a 22 kWh battery pack. We chose to buy the version with the optional range extender, a 34 hp (25-kW) two-cylinder gas engine that generates electricity when the battery runs dry; it’s not connected to the wheels so can’t drive the car directly. It kicks in to extend the range and keeps the battery level at 6 percent. That works fine in most situations, when you have regenerated electricity from coasting and braking to add to the battery charge, but when you need sustained power such as for climbing a hill, it’s a different story.

Showing low state of charge.

Here’s the scenario one of our test drivers experienced on the way into the office: When pulling out to pass a slower vehicle after climbing a long hill, the reserve power ran out, and the car cut power while he was out in the oncoming traffic lane. That was disconcerting, to say the least.  

After we contacted BMW, the company promised a software update this spring.

After making the update on our i3, we noted the addition of a state of charge (SOC) function in the onboard computer. As long as you’re in electric mode, and given the fact that you have a range left indicator, an SOC display doesn’t seem all that critical. But when you are in range-extending mode, relying on the little gas engine to act as a generator, this information becomes more useful. In that mode, the car aims to keep the SOC at 6 percent, but it can fall below that, such as on a sustained hill climb. When state of charge drops to 2 percent, the i3 now gives you an audible chime and an exclamation mark with the a notice “Low battery, power reduction possible.”

An advanced warning is a good thing. Drivers should heed the warning but the new software doesn’t address the power reduction itself as BMW said it would back in the fall.

Eric Evarts and Gabe Shenhar

Find Ratings

Hybrids/EVs Ratings

View and compare all Hybrids/EVs ratings.

E-mail Newsletters

FREE e-mail Newsletters! Choose from cars, safety, health, and more!
Already signed-up?
Manage your newsletters here too.

Cars News


Cars Build & Buy Car Buying Service
Save thousands off MSRP with upfront dealer pricing information and a transparent car buying experience.

See your savings


Mobile Get Ratings on the go and compare
while you shop

Learn more