Solar Impulse Grounded Due To Battery Damage

JUL 12 2015 BY MARK KANE 9

Following the record-breaking oceanic flight of 5 days and 5 nights (117 hours and 52 minutes), #Si2 will undergo repairs on the batteries due to damages brought about by overheating.

Following the record-breaking oceanic flight of 5 days and 5 nights (117 hours and 52 minutes), #Si2 will undergo repairs on the batteries due to damages brought about by overheating.

After nearly 5 days and nights of non-stop flight from Japan to Hawaii, Solar Impulse 2 is stuck for at least 2-3 weeks.

The reason is battery damage due overheating. Overheating apparently could be caused by too much insulation.

The team must now figure out how to deal with the problem and which parts need to be replaced.

“Following the record-breaking oceanic flight of 5 days and 5 nights (117 hours and 52 minutes) in a solar-powered airplane, Si2 has suffered battery damages due to overheating. The damage to certain parts of the batteries is irreversible and will require repairs and replacements that will take several weeks to work through.

Consequentely, Solar Impulse does not see the possibility for any flights before 2-3 weeks at the earliest. Regular updates will follow.”

It could be a very costly delay for the project, because if Solar Impulse 2 arrives on the East Coast too late, it will not be able to fly across the Atlantic this year, according to BBC:

“If Solar Impulse cannot get to the US East Coast soon, the project team may find that the correct meteorological conditions for an Atlantic crossing are no longer available in 2015.

The vehicle’s slow speed, light weight and 72m wingspan put significant constraints on the type of weather it can handle. And beyond August, the windows of opportunity to cross the second biggest ocean on Earth become few and far between.”

source: BBC

Categories: General


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9 Comments on "Solar Impulse Grounded Due To Battery Damage"

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Did the BBC run out of news readers? It sounds quite odd to hear the story read by a computer, though it did a passable job.


Sound like Stephen Hawking.


Battery pack cooling…a problem for many of us Leaf owners.


I wonder if this is more out of an abundance of caution. They did make the Japan to Hawaii trip just fine and I presume that is the longest one. But perhaps they’ve noted some reduced capacity in the batteries and thus want to replace them just to be safe.

Not sure why it would take 2 to 3 weeks to fix though. Just FedEx out some new cells and swap them in for the damaged cells. (Of course that use of the jet-powered fedEx kinda detracts from their solar/battery only flight.)


(1) The Solar Impulse 2 may not be using off-the-shelf batteries. If they’re using a specially made type for very high energy density/low weight, it may take days or weeks for a laboratory to make a new batch.

(2) Designing and building the Solar Impulse 2 involved 80 engineers, according to their website. There is always a certain amount of jerry-rigging in building a prototype vehicle, especially one as complex as a solar-powered airplane. Replacing vital components is not likely to be a plug-and-play process, especially if those who built the plane are not there to help with a replacement.


In engineering, the fix like Speculawyer said, is easy. Maybe a bit of hassle trying to FedEx “hazardous” material like Li-ion batteries but actual parts swap is no problem.

Biggest problems are validation and qualification. Lots of tests/work needed before the product is certified ready to be deployed again. More if failure analysis and engineering work are required to prevent the issue from recurring.


My guess is that the batteries are nearly structural given the constraints of the project, therefore you will need to tear it down to find the failed/damaged batteries, or worse that they must test each ‘pack’ to determine its usefulness.
Guessing also that their air-cooling design program missed a critical airflow issue to have such a harmful result.


They need two separate battery modules with switch technology.
While module (A) flies the plain module (B) gets charged via solar panels.
When module (B) is fully charged, charging should stop for a few minutes to cool the module then switch technology should switch module (B) to flight mode and module (A) to charge mode. Module (A) should begin charging when cooled to desired temperature.
When module (A) is fully charged repeat the switch process.


no comment

given that they have abandoned this project for the rest of this year, you have to wonder what is the point of continuing this effort?