Abstract: An exterior power supply for a hearing aid has a battery-shaped conductor, two thin power contacts, and a DC power source. The battery-shaped conductor is received in a battery container of the hearing aid and has a top electrode and a bottom electrode. The thin power contacts are mounted to the battery-shaped conductor and respectively and electronically connected to the top and bottom electrodes of the battery-shaped conductor. Each thin power contact has a thickness matching a gap between an opening and a door of the battery container of the hearing aid. The DC power source is electronically connected to the battery-shaped conductor through a power wire and the thin power contacts to output DC power to the top and bottom electrodes of the battery-shaped conductor. Therefore, the hearing aid obtains DC power from the battery-shaped conductor and the button cell is not replaced frequently.

Abstract: An exterior power supply for a hearing aid has a battery-shaped conductor, two thin power contacts, and a DC power source. The battery-shaped conductor is received in a battery container of the hearing aid and has a top electrode and a bottom electrode. The thin power contacts are mounted to the battery-shaped conductor and respectively and electronically connected to the top and bottom electrodes of the battery-shaped conductor. Each thin power contact has a thickness matching a gap between an opening and a door of the battery container of the hearing aid. The DC power source is electronically connected to the battery-shaped conductor through a power wire and the thin power contacts to output DC power to the top and bottom electrodes of the battery-shaped conductor. Therefore, the hearing aid obtains DC power from the battery-shaped conductor and the button cell is not replaced frequently.

Abstract: An exterior power supply consists a positive and negative power contacts located in the hearing aid, a wire, and a power supply. The electrode contacts use two pieces of thin plate connecting to the wire, which passes through the battery container without modifying the structure of the hearing aid. At the other end of the wire is the power supply that can be a combination of a solar cell with a chargeable battery, or a normal small battery. The multi-functional power supply has a circuit offering an electricity conduction circuit, an auto loud noise control circuit detecting background noise volume and being stopped temporarily as though the noise is overloaded and started automatically once the background noise volume is back to the normal level, and a voltage regulator circuit to control an output voltage always be 1.4 V.