During the first ascent of the flight from Nagoya, Japan, the battery temperature increased due to a high climb rate and over insulation of the gondolas. And while the Mission Team was monitoring this closely during the flight, there was no way to decrease the temperature for the remaining duration as each daily cycle requires an ascent to 28,000ft and descent for optimal energy management.
The Solar Impulse team said that overall the airplane performed very well during the flight. The damage to the batteries is said not to be a technical failure or a weakness in the technology but rather an evaluation error in terms of the profile of the mission and the cooling design specifications of the batteries.
Irreversible damage to certain parts of the batteries will require repairs which will take several months. In parallel, the Solar Impulse engineering team will be studying various options for better cooling and heating processes for very long flights.
Post-maintenance check flights will start in 2016 to test the new battery heating and cooling systems. It is said that the round-the-world mission will resume in early April from Hawaii to the West Coast of the USA.
