My battery charge was getting around 23 miles at 100% charge the first two -three months of owning the car. The last three months though the battery is only registering at 15 miles at 100% charge. I have been reading some posts about cold weather affecting the battery or the heater depleting the miles but neither of those factors were present during the noticeable decline of my mileage. The cold weather has just now started in the last month but cold here is 57 degrees overnight , so not too cold. Anyway, I tried resetting my mileage and hybrid settings but that only boosted my mileage up by a mile or two. Any suggestions on how I can get back to those original 23 miles for a 100% charged battery?