Battery options for the FrSky Taranis RC transmitter

Thought it would be possible to change the Taranis stock battery with a bigger battery. But apparently it's not as easy as expected.
Having to solder another plug onto the battery and changing the settings for voltage alarm can be tricky, though it's not that difficult. 
Can imagine this is handy or necessary for extremely long flights where you can't land between switching batteries.
But for short flights maybe it is easier to just buy 1 or 2 extra stock batteries for the Taranis.

He says he thinks the standard taranis battery will last 3 hours,that`s plenty long enough for me