Rechargeable hearing aids typically use lithium-ion batteries. These batteries can retain a lot of energy in a little amount of area thanks to their high energy density. They also feature a low self-discharge rate, which implies that while not in use, they will maintain their charge for a longer time. Furthermore, lithium-ion batteries do not experience the “memory effect,” allowing for unlimited charging and discharging without gradually losing power. These characteristics make lithium-ion batteries well-suited for use in rechargeable hearing aids.