Balloon flight B-7, 22 July 2013

An attempt to evaluate use of Zinc-Air batteries for low altitude balloon flights.

Zinc-Air cells have the highest specific energy of all primary batteries in common use because oxygen partcipating in the electro-chemical reaction is collected from the air and does not have to be carried inside the cell like in batteries of other types. However they need a supply of air and to stay relatively warm to operate. Both of these requirements are problematic at 7000-8000m altitude.

An attempt has been made to increase air supply to the cells hoping this will prevent them from oxygen starvation during bursts of consumed current but the resut was still un-satisfactory.

Flight computer stopped operating 3 hours into the flight at altitude of 7200m.

Payload weight - 16.6 grams.
Free lift - 1.0 grams.
Downlink mode - DominoEX 16
Launch time 8:20 local time (7:20 UTC)

Flight path:

Altitude in metres: