Yes, the Ring Doorbell 2 can charge its battery even when it is hardwired. When it is connected to an electrical outlet or an existing doorbell system using the included charger cable, it will be able to draw power from the electrical outlet or doorbell system to charge its battery. In this case, it will function as a wired device, which means it will not rely on its battery for power. Instead, the battery will be used as a backup power source in case of a power outage or other issues with the electrical connection. This can be a good option for those who do not want to worry about manually charging the battery or want to ensure that the device is always ready to use.