I started out with good intentions. During training, I kept track of landings, take offs, # of flights, etc. Once I solo'd, the logging began to get missed. I did start a battery tracking chart, but found out later my system needed modification along with the spreadsheet. While I am not tracking batteries now, I plan to redo my system and begin tracking them. I try to re-cycle each battery once a month and find I am losing track. It's easy when you have 1 or two planes, but the more you get, the harder it is to remember. (Although I have been told that age is the real culprit.) Mine, not the battery.