Each Alta X flight requires two 12S batteries, so you'll need a charger like this that can charge two at a time. 

This battery charger is a dual output balancing charger with an integrated power supply. It can charge two Alta X Flight Packs at once at a max rate of 1200W per channel, in less than two hours (for fully depleted batteries). 

We include all necessary cabling and accessories to allow users to charge two Alta X Flight Packs at once. 

• Qty 1 - Dual Channel 12S LiPo Charger
• Qty 2 - XT90 Charging Leads
• Qty 2 - Balance Leads for 12S Alta X Batteries
• Qty 2 - Balance connectors for 6S/10S/12S LiPo batteries (not 14S)
• Qty 1 - Power cable (110V US style plug)