FrSky supplies the Taranis with a 800mah battery that has prooven to supply many hours of use due to the efficiant design of the Taranis, but lets face it, when programming and or long flying days we could use a bit more. This upgraded battery by FrSky allows over twice the up time thanks to its generous 2000mah rating and the low self discharge means it will keep its charge a lot longer when sitting around. Just what the doctor ordered!Please note that early Taranis owners may need to run their charge cycle twice when first charging this battery, or when charging a deeply discharged pack. To do this, simply wait until the charge light turns off on your transmitter, then turn the Taranis on, and then off. The charge light should light back up and start charging again. Radios made from October 2013 on will not have this issue.