omni 20+ 20000mah laptop power bank | ac/dc/usb-c/wireless battery backup for laptops:macbook pro/ipad pro/dell/surface | cameras:canon/nikon/dslr/dji drones | smart devices:iphone/samsung omnicharge faq q: how do i use the wireless charging? a: for optimal wireless charging, place your phone horizontally towards the back of the omnicharge. q: how long can the omni 20+ power my device a: to get an estimate of charging time, you can use the formula below. please note that this is just an estimate, and that power consumption will vary based on different usages. for example a laptop which is powered off will potentially draw less power than one that is running heavy software. 71wh / power draw of device(w) * 0.85 example 13" macbook pro: 71wh / 60w * 0.85 = 1hour please note: this does not account for the built in battery of the laptop, and calculates the maximum power the laptop can draw. in reality, once your laptop battery is full, the laptop will draw significantly less power (depending on usage). you can find your devices rated power draw either on the back of the device, or on the devices wall charger.