Bought a DJI Phantom3SE drone off them, thereafter 2x spare compatible batteries. All working AOK. Bought a 4th battery - dead. So far, contacted *******@tomtop.com twice to return/replace - still awaiting a >relevant< response... Have actually had 2x replies... to leave reviews on review-websites?! Fingers crossed this will be sorted out soon, as usually good product at good prices...