How Far Does Your Car Go?

As it stands, the Smart ForTwo Electric Drive has an EPA estimated range of 68 miles. The average U.S. driver covers about 30 miles per day.  It would seem that the electric Smart more covers this by more than double.  But in the near future, your car could go a great deal further.

It's been said that "your mileage may vary".  The EPA estimates that the Smart ForTwo ED gets between 92 and 122 miles per gallon equivalent to gasoline (MPGe).  Unlike internal combustion engine (ICE) vehicles, for EVs the low number is on the freeway, and the high number is on the street.  But the average still comes out to about 108 MPGe.  The EPA also sets a range for ICE vehicles, which on average tends to hover around 25 MPG.

How far does your car go on a full tank or battery? Does it go 250, 300, 500, 1000 miles?  The average range on a tank of gasoline tends to be between 250 and 300 miles.  Whereas the average for an EV tends to be around 100 miles. For an ICE vehicle, the range depends how many gallons of full can be carried.  The same goes for electric vehicles, but for kWh of charge.   But what if the capacity of the battery could be drastically increased, in the same space?

Currently gasoline has a strong advantage over even the battery that can hold the most charge.  In terms of charge density (Wh / kg) gasoline holds 13,000 Wh / kg.  The technology in electric cars today has a charge density of 250 Wh / kg, a ratio difference of roughly 50 to 1.  Even with the 4 to 1 ratio of better performance over ICE, EVs still can't compete.

However, there's a new technology that's being worked on in chemical labs around the world.  IBM is one company that has taken a strong interest in the idea of greatly improved battery capacity.  The new technology is called Lithium Air and promises to increase the energy density of batteries to 11,700 Wh / kg.

As noted above the Smart ForTwo ED has a range of 68 miles.  With the new Lithium Air battery, and without changing the size of the battery, the range could be increased to as much as 3,182 miles.  I currently drive about 10,000 miles per year.  At this rate I might recharge every 4 months.  The battery in the Smart ED is now 17.6 kWh, with Li-Air it would 813.1 kWh (that's 0.8 Megawatt-hours).  At current electricity prices where I live that's only $80-worth of electricity.

Check out this video that IBM created to better explain the idea of Lithium Air