D chargers feature protections to avoid overcharging; however, leaving an e-bike battery plugged in overnight may overheat and damage its internal circuitry. To maintain optimal battery health, it's best to abide by manufacturer recommendations. This may involve keeping your battery charged at 40-80% capacity or higher and operating under optimal temperature ranges. https://ebikereviewerdentinygraves.blogspot.com/2024/09/is-it-ok-to-leave-my-ebike-on-charge.html