Christopher

Thank's for the response, I appreciate the info and I have been to Red's site. the group cell average I was unaware of. But makes sense, Not all cells will read the same when they are new. So 500 hundred would seem to be a good point for reference. (I only wish My Dewalts would last that long)!

Bet wishes for fair weather and safe landings"
FUN= flying until nightfall

Dan Z