Flying around the world on only the power of the sun turns out to be more of a stop-and-go affair than even the team behind Solar Impulse 2 may have guessed. The solar-powered, single-pilot aircraft began circling the globe from Abu Dhabi back in March, but must now remain in Hawaii until early August. While Swiss pilot and Solar Impulse co-founder André Borschberg survived a record-breaking five-day flight from Nagoya, Japan to Oahu with just minimal sleep, SI2's batteries didn't all fare so well without rest.
After checking out the plane on the ground in Hawaii, the Solar Impulse team now reports that irreversible damage to certain parts of the batteries will require repairs and replacements that will keep the craft out of the air for at least the next 2-3 weeks.
Over-insulation of the batteries caused them to overheat during ascent on the first day of the Japan to Hawaii leg. The team says that while this situation was closely watched during the flight there was no way to decrease the temperature during the record-breaking flight, which required daily ascents to 28,000 feet for energy-management reasons.
While Solar Impulse 2 undergoes repairs, the team also says it will be looking into ways to better deal with heating and cooling during long flights.
Once it's ready to get back in the air, the journey continues to the US mainland, where a few stops are planned before setting a course over the Atlantic and eventually back to Abu Dhabi.
Source: Solar Impulse
Flying around the world on only the power of the sun turns out to be more of a stop-and-go affair than even the team behind Solar Impulse 2 may have guessed. The solar-powered, single-pilot aircraft began circling the globe from Abu Dhabi back in March, but must now remain in Hawaii until early August. While Swiss pilot and Solar Impulse co-founder André Borschberg survived a record-breaking five-day flight from Nagoya, Japan to Oahu with just minimal sleep, SI2's batteries didn't all fare so well without rest.
After checking out the plane on the ground in Hawaii, the Solar Impulse team now reports that irreversible damage to certain parts of the batteries will require repairs and replacements that will keep the craft out of the air for at least the next 2-3 weeks.
Over-insulation of the batteries caused them to overheat during ascent on the first day of the Japan to Hawaii leg. The team says that while this situation was closely watched during the flight there was no way to decrease the temperature during the record-breaking flight, which required daily ascents to 28,000 feet for energy-management reasons.
While Solar Impulse 2 undergoes repairs, the team also says it will be looking into ways to better deal with heating and cooling during long flights.
Once it's ready to get back in the air, the journey continues to the US mainland, where a few stops are planned before setting a course over the Atlantic and eventually back to Abu Dhabi.
Source: Solar Impulse
Nissan Leaf did suffer from heat damaging the batteries, but they don't insulate the batteries (or heat or cool them) at all. The SI2 insulated the batteries from the cold of high altitude, but apparently didn't include any cooling when they got too hot, so the heat was trapped in the batteries.
Hopefully its a lesson learned.
Unlike the normal changes on the ground for automobile batteries that take place the one happening in such an aircraft is much faster. So their calculation for insulation was wrong. They will go back to the drawing board and fix it.
" Had they simply locked the wheels and ran it for more than 24 hours they would have known about this issue before they wasted their time. " They would also have to simulated the ambient temperature at flight elevation. Not as easy as said.