Brand new M-10 owner here. Curious as to the battery indicator and its significance. I know most praise the unit for long battery life. But when is it time to replace? I just lost the first segment in the indicator during a show last night. Does each segment correspond to X hours of recording left? Replace now? I would hate to lose any music for the cost of a pair of AAs, but don't want to change prematurely either. Thoughts?