Upgraded my Bane. Went from Ligtht side to Dark side.

[Ultra]

It's not the single battery setup causing the decrease in battery life; it's the fact that the Obsidian XT needs more power for the additional features (4 watt amp, FoC).  However, due to the efficiency of the XT's single-cell setup, having two batteries (one installed and one spare) will actually net you a longer run time than the previous setup of two batteries installed at the same time.