TX-5608 built in 8000mAh battery inside. When there are power you don't need to plug it into any power source. It is more convenient and portable. It only charge by wireless but also by cable at the same time; Compatible models: Nokia Lumia 920 / 820 LG Nexus 4 HTC 8X etc. all the QI standard compatible electronic products; Ultra-thin 10mm; Suitable for devices meeting QI standard; Samsung Galaxy S3 i9300 S4 i9500 Note 2 N7100 need to buy external wireless receiver. How should I start charging my Qi-enabled devices? 1. Please confirm that your cellphone is Qi-compliant and comes equipped with a charging chip. 2. If there's a green indication light from the charger the phone is charging wirelessly. However if there is not any green indicator light move your device to the center of the charger. This should commence the charging process. 3. Attention: Protective cases that exceed 5 mm / 0.2 inch thick prevent the charger from working properly. In this case remove it before charging.