This product is not a battery. Placing the PowerClip over the wireless charging ports on the PowerMat or Expansion Modules charges the tool and provides the professional barber or stylist with a true, hassle-free wireless experience. The PowerMat, Expansion Module and PowerClip uses patent protected methods to enable wireless charging for the most popular clippers, trimmers, and shavers on the market. Additionally, the ecosystem enables wireless charging for the most common wireless charging capable devices wireless charging pad required to charge clipper with powerclip. If there are any issues charging the trimmer please contact customer service as it may not be the poweclip and an issue with the wireless charger.