No one will notice
Improvements in technology happen all the time, no one notices. We don't need batteries that last longer, we already have seen this happen, especially in mobile phones. Low power devices that allow batteries to last 3 times as long are then fitted with 4 times the amount of stuff so that the battery lasts even less time than before the technology arrived.
You make a battery so that a car can travel 3 times more distance and that car will get fitted with a more powerful motor and bigger steel to protect the occupants to bring down the range to what the buyer expects...and no one will notice the new technology.