The DJI Battery Charging Hub for Mavic Air Intelligent Flight Batteries can recharge up to four batteries. Plug in your Mavic Air's AC adapter or car charger and you'll be ready, with all four batteries done charging in around 3.5 hours. Batteries are charged sequentially in order of most to least charged. This ensures that you'll have at a fully charged battery as soon as possible. Put your depleted batteries on charge before a shoot and be ready to fly.