ORIGINAL: GerKonig
ORIGINAL: nonstoprc
I just disconnect the center wire between the two 5c battery after landing and set the pack aside. A fully charged pack, on the other hand, has the center wire connected.
Some other ways to tell whether a pack has been used: a quick voltage check with a voltage meter and/or check the temperature of the pack.
I am forgetful, and some of my batteries are exactly alike. I put a small rubber band around batteries when I take them out of the model, and remove them when I charge the battery. Works for me, I have a bag of them in my flight box, and I put some in my pocket at the field...
Gerry
That method also works. A contest buddy of mine told me that.