A rechargeable hearing aid comprises a battery charger and a hearing aid body. The battery charger presents an easily carried case, which is provided with a receiving groove and a battery chamber, which contains a dry battery for power supply. The receiving groove can receive the hearing aid body and is provided with connection terminals at two sides of the inner groove for flexibly locking the hearing aid body. A cover covers on the receiving groove and is pivotally connected to the bather charger by a hinge element, which is further connected to a switch, such that when the cover is in the position of OFF, the battery can start recharging right away, and be quickly completed with micro-voltage.