You don't need to recharge it. The battery ensures over 5 years of use. If the battery completely discharges before 5 years, we will send you a replacement equivalent to your Perifit model for free and recycle the old one. If it completely discharges after 5 years, we will offer you a replacement equivalent to your Perifit model for only $50. Only with presentation of a proof of purchase (order confirmation email or invoice).