From the story:
Scott Yarosh wrote:"When I first purchased the vehicle, I could drive to and from work on a single charge, approximately 90 miles round trip," Yarosh said.
And now, he says, "I can drive approximately 44 miles on this without having to stop and charge."
Yikes! Who was it that said most owners wouldn't notice if they didn't have the capacity gauge
I think we should all plan on losing drivable range faster than we lose capacity in a BEV. There are at least two reasons to expect this:
1) At the same time the capacity of the cells is being reduced, the resistance of the cells is being increased, likely by a larger fraction than the capacity reduction. This increase in resistance means that the battery will be less efficient and that you will lose more range than just what would be indicated by just a capacity calculation. (BTW, this additional loss will mean higher temperatures in the battery, as well.)
2) Unless we are willing to call a tow truck to get to our destinations, we all have a "mental reserve" that we add to any trip to ensure that we get to our destination. For some it may be bars, for others, it may be GOM miles and for still others it is GIDs. Whatever it is for an individual, it is what they are comfortable with and it does not change as the capacity decreases. For illustration, let's take a case where a driver can travel 90 miles in their BEV when it is new until they *believe* that they only have 10 miles left. They likely will feel they have a car with a 90-mile range, even though the car can go 100 miles. Then let's say the car loses 50% of its range. This driver may then feel they have a car with only a 40-mile range. The car has lost 50% of its range, but because of the "mental reserve" needed to get safely to a destination, the driver feels the car has lost 56% of its range.
In this case, perhaps losing three bars results in a range loss of close to 35% when resistance increase is included. Combining that with the idea of a reserve needed to get to a destination, then the numbers don't seem too crazy.