Battery options for the FrSky Taranis RC transmitter - YouTube
Amazon.com: X9D Plus Battery 7.4V 3000mAh 8C Rechargeable 2S Lipo Battery for Frsky Taranis X9D Plus Radiolink Transmitter 2 Pack with USB Charger : Toys & Games
Replacing the RTC Clock battery in a FrSky Taranis X9D - YouTube