Highplains, I suggest you break down and buy a Voltwatch and test one for yourself before flipping off about how they are uncalibrated and a waste of $$. I did and based on my findings I believe the Voltwatch to be an accurate indicator of weather the receiver batteries are safe for another flight or not. Check out the review here: http://webpages.charter.net/rcfu/FER...ltWatch.html:D