No damage to the charging device, because we use smart chips to provide stable charging current ,Built-in overheat, overcharge, overcurrent, overload, surge, short circuit protection in the multi usb charger, protecting your devices automatically and greatly extending the battery lifetime of your devices. With 20 Smart USB ports, that can each charge at upto 2.4A your devices can get charged much faster then regular 1A chargers! Adaptive smart chip detects and delivers the optimal charging current for connected devices. Phone docking station protects against overcharge, overcurrent and short circuit.