One of the guys down our local field is slowly coming up to speed with ECL, he's been an ERC flyer for some time so is no novice when it comes to brush-less motors, lipos etc. He commented after 1 flight he had X% left in a pack so was going to increase the flight time. How do you know? I asked... so he showed me his "Hyperion EOS sentry" unit.
What a great piece of kit.

I already have a cheap device which tells me the voltage of each cell and total voltage of the pack (And this has saved me from putting a half charged pack into a model a few times). The Sentry seems to be an extension of that, It provides info on cell voltage, Pack Voltage, Voltage difference across cells, %age charge left in the pack. I was impressed and had to get myself one.
http://www.hyperion.hk/dn/sentry/man/EosSentryMan12-EN.pdfWorryingly the %age figure it gives is around 5% higher than the reading I see when I 1st connect a pack to my Hyperion 1210i and as both products are from the same company I wonder why the different calculation methods (and which one I should believe).
Just wondered if anyone else was using one?
TTFN
John.