????
My batteries seemed to last forever. They only time I can recall them losing power was in sub-zero conditions.
Dunno what to tell ya. My SRT-102 never gave me prollems with 20+ sec exposures all night long (across multiple rolls); the X-370 crapped out on me repeatedly w/in course of a single roll - dead batteries. That, notwithstanding, that condition never happened in hand-held shooting environment.
Perfect example is meteor shower observing. Doesn’t matter if its Perseid or Leonid - one being colder than the other - the X-370 don’t like long term open shutter condition; at least mine don’t.