update on battery voltage-
Flight time 18 mins of hovering at 650ft above sea level with 10mph winds.
ST 16 reported 14.3v warning and i landed immediately.
As soon as landed ST 16 voltage showed 14.6v so battery did recover.
pulled lipo out and used my lipo meter, each cell was 3.68v less than 30 seconds after landing....so the st16 is accurate enough.
my lipo meter is showing 15% left in the battery which is about right.
edit- battery charged and took 5595mah.
this means it uses 18.66 amps average in the above flight conditions.
I too took a flight with stock battery. 18 min 20 seconds, landed at 14.3 volts.
Give or take 0.02 volts and 5599 mah on recharge my numbers match yours.
(using a Hitec charger)
If I have time later I am going to hook a dowel rod to the landing gear and see how well it will do with a rearward center of gravity. I am sure it can handle quite a bit but at the expense of lower battery life.