jzchen wrote: ↑
Sat May 11, 2019 12:15 am
Rereading what I said it doesn’t quite make sense. My apologies.
A brand manager for smart at a local dealership said some EV (ED) owners ran the car until it stopped. This ended up damaging the battery.
While generally considered to be not a good idea to drive until a BEV doesn't have any
juice left (inconvenient to wait for a tow to say the least), doing so will not in and of itself damage the battery. Repeatedly driving to a very low SOC will be worse for long term battery health, but all manufacturers leave a buffer at the bottom of the pack so it is never truly fully discharged (they car will shut off first). Similar to the 2 bars the PHEV always displays with zero EV range left.
If the smart vehicles were truly damaged by running till they stopped, it is either a faulty BMS or even battery. I seriously doubt the design would allow for running out of fuel to permanently damage the vehicle. It is more likely that the vehicles in question were routinely run to a very low SOC and the battery suffered some degradation as a result - hence the "damaged battery" diagnosis. With a 58 mile range and primarily urban usage, smart cars are more likely to be run to a point with only a couple of mile range remaining.
As an interesting note, on the Bolt forums, some people start espressing "range anxiety" when the estimated range gets below about 80 miles. This is more than the entire range of the smart car, many used LEAF's, first gen cars in cold weather, etc (or even the Clarity BEV in cold weather - it is essentially a "first gen" EV with it's sub 150 mile range).
Most BEV's are not routinely driven to a very low SOC. We typically recharge after 30-50 miles.