Originally Posted by BEC

Scott - NiMHs REALLY don't do well if allowed to go flat, and they self-discharge faster than NiCds and much much faster than lithiums. So you need to pull them and top them up on some kind of regular basis whether you're flying or not....or you'll be throwing them away and buying again, which kind of defeats the whole point of the things. This is coming from years and years of electric-powered RC airplane experience stretching back to the early 1980s. NiMH batteries promised much but their self-discharge rates really mess things up.