State of Charge Gauge Missing On BMW i3: BMW Says You Won’t Need One

As any electric car driver will tell you, the most useful gauge on an electric car’s dashboard — aside from perhaps the speedometer — is the one which displays the car’s state of charge (SOC). We’re not talking about a basic, segmented bar graph representing with terrible resolution an approximate representation of how much charge is remaining, or a digital display detailing how many miles are left before you’ll need to plug in.  We’re talking an honest-to-goodness gauge showing the remaining charge as a percentage — and it’s one of the most commonly requested features drivers ask automakers to include in any new EV.

There's no SOC gauge on the 2013 BMW i3... at least for now.

There’s no SOC gauge on the 2013 BMW i3… at least for now.

The most useless gauge on an electric car’s dashboard? That’ll be the aforementioned ‘miles till empty’ display, commonly refereed to by many EV drivers as the ‘guessometer’ due to their notorious inaccuracy and ability to dupe first-time EV drivers into thinking their cars can travel further than they really can.

So why has BMW, maker of one of the most eagerly anticipated electric cars on the market, decided to include a guessometer and not an SOC gauge, despite a long-and extensive multi-year test-fleet of electric cars which did include an SOC gauge that owners raved about?

BMW says the new BMW i3 has such accurate range prediction features that a traditional SOC gauge isn’t needed, but that’s a big mistake, say some of BMW’s biggest electric car supporters.

That’s according to BMW ActiveE ‘electronaut’ and long-time EV advocate Tom Moloughney, who confirmed on his blog that the highly-anticipated car won’t include an SOC gauge.  At least, U.S. versions of the car won’t, and those European cars which include a state of charge display will have it displayed on a hidden screen on the centre console.

“During the MINI-E and ActiveE trials the participants like myself were very clear that we liked the state of charge display,” Moloughney told us earlier today. “I personally conveyed this to the program managers and engineers on a few occasions myself. It will be disappointing if there is no state of charge gauge on the production i3.”

Sexy urban chic -- and good at maths, apparently.

Sexy urban chic — and good at maths, apparently.

As well as providing a really accurate representation of the true amount of energy remaining in an electric car’s battery pack,  SOC gauges are far easier to read on the road than a constantly changing ‘guessometer’. That’s because guessometers traditionally use historic energy consumption data to predict future range, and do not take into account changes in road conditions, traffic or how full the car is and can actually rise and fall during a single trip. An SOC gauge meanwhile, only does one thing: it counts down remaining power until the battery pack is empty or the car is plugged in to charge.

This isn’t the first time an automaker has made the error not to include an SOC gauge. When the Nissan LEAF launched back in 2010, it chose to give the LEAF a twelve-segment bar-graph to represent the remaining charge in the car’s battery pack, alongside a numerical representation of estimated remaining range. However, after consistent complaints from owners over the inaccuracy of this setup, Nissan introduced a user-selectable SOC gauge as a standard-fit item for all 2013 Nissan LEAFs and newer.

Moloughney says the ‘obvious critical error’ could have easily been avoided by BMW,  and explained that at a recent private event at the LA Auto Show for existing ActiveE drivers, BMW executives were given a hard time by those there for not including an SOC gauge as standard.

“BMW tried their best to explain that the i3’s range predictor will be so accurate that a proper state of charge gauge isn’t needed,” he said. “That didn’t sit well with the ActiveE drivers and the protest continued until the manages said their hear our displeasure and promise to revisit this.”

While the U.S. version of the BMW i3 will likely not ship with an SOC gauge however, Moloughney said that European versions of the i3 REX — the range-extended version if the i3 which will allow owners to manually switch the car’s tiny 660cc range-extending engine on and off to ‘save’ the battery pack’s charge for zero-emissions city driving — will have a hidden SOC display, accessible from the car’s main multifunction iDrive menu system. The U.S. version of the i3 and i3 REX however — which will not allow owners to switch on the range extending engine as desired in order to comply with tough Californian emissions regulations — will not.

BMW won't be including an SOC gauge in U.S. cars -- and only on European REX models.

BMW won’t be including an SOC gauge in U.S. cars — and only on European REX models.

Moloughney remains hopeful that BMW will hold true to its promise to revisit the inclusion of a SOC gauge in the future, either as a software update for existing i3 owners or a feature in the next generation of the car. Even though he’s visibly disappointed however, Moloughney says he’ll still likely buy an i3.

“Will this prevent me from buying an i3? No. Will it make the driving experience much worse? Probably not,” he says. “What bothers me more than anything else is this is something the MINI-E and ActiveE were overwhelmingly in favor of and I don’t know how BMW missed it. The point of the MINI-E and ActiveE trials were to find out things like this so the i3 and future BMW electrics would be the best they could be. I hate to really harp on this so much but I’m really disappointed this was somehow overlooked.”

Do you agree? Would this put you off buying an i3, or do you think it’s a tiny omission letting down what is otherwise a great car? Leave your thoughts in the Comments below.


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