BTG 2s 3s 7.4v 11.1v Li-po/li-ion Battery Balance Charger for DJI Phantom FC40 Parrot Ar Drone 1.0/2.0/3.0 Walkera Qr X350 Blade 350 Ladybird Syma X5c X5a Hubsan H107l H107c H107d V959 U817a U818a