When connected to a Mavic Air 2 charger or car charger the Mavic Air 2 Battery Charging Hub can be expanded to charge three additional batteries.&lt;br /&gt;&lt;br /&gt;It is designed for use with the Mavic Air 2 Intelligent Flight Battery.&lt;br /&gt;&lt;br /&gt;The battery charging hub enhances efficiency by charging batteries in sequence according to their remaining power level with more fully-charged batteries receiving power first.