If you leave the fob within range of the bike when parked, it's going to eat the battery, since the system never goes to 'sleep'. I checked the battery on my 2015 bike, which I purchased the day it arrived, and it was quite low. Replaced it with a Panasonic, which is considered the best brand of such batteries due to having a hash-tag pattern on the '-' side, making better contact. We'll see how long it lasts when kept away from the bike. But will check it again in a year. Bought a lot of batteries, since they're used on many other gadgets, from heartrate monitor bands/watches, garage door openers, etc.