【Up to 15Vx6.8A】The surface charging cable is up to 15Vx6.8A, depends on the power of PD charger. If the power of PD charger is not enough, your surface might show "Slow charging cable is connected", it just says you will take more time to charge your surface, but you can work and entertainment normally. 【Charging Conveniently】Allows you charge your Surface devices via 45W 15V3A or upwards of 45W USB-C Power Delivery (PD) wall charger or power bank, you only need to bring a USB C charger to charge many devices including Surface on the go. It is very lightweight and portable. 【Charging Power Requirement】: This cable requires an USB-C charger or charging bank that support 15V 45W or upwards of 45W output for Surface Pro and Laptop.. Doublecheck your USBC charger to ensure that it lists "15V/3A or higher current" in the specifications. 【Compatibility】: Designed professionally to charge your Surface Pro 8/7/6/5/4/3, Surface 3, Surface Laptop, Surface Laptop 2, Surface Studio, Surface Book 1/2, Surface Go. (NOTE: Please use USB-C PD Charger)