After smoke erupted from the lithium-ion battery pack aboard one Boeing 787 Dreamliner, and fire in another, the Federal Aviation Administration [FAA] grounded the whole fleet.
After weeks of testing though, neither FAA investigators nor Boeing engineers have been able to determine the cause of the smoke and fire in the Boeing 787 Dreamliner’s battery. Boeing’s fix, a new stainless steel battery box, some say, will just contain a fire.
Think for just a moment though, what does a fire need in order to start? Fuel, heat, and oxygen. Now, the stainless steel battery box isn’t hermetically sealed, but it is closed off enough from the atmosphere, Boeing engineers say, to prevent a fire from occurring.
The fuel in this case is the electrolyte. Inside the steel battery box, in the absence of free-moving oxygen, the electrolyte can’t ignite. The only reason for electrolyte to be venting, a runaway thermal event, is if the battery is overcharging. Engineers say that, so far, none of the Boeing 787 Dreamliners have had any problems overcharging. Still, the new battery box is also designed to reroute overheated electrolyte and vapors through a titanium tube venting outside the plane.
The only problem with this solution is weight. Granted, on a vehicle that maxes out at 550,000lbs, the additional 150lb stainless steel battery box on the Boeing 787 Dreamliner doesn’t seem like a problem. The rest of the engineering and design of the plane, using lightweight composite materials to increase the capacity as well as fuel economy of the new craft. The addition of an extra 150lb may fly in the face of the lightweight and economical, but I don’t think that anyone can make the case for a less-safe aircraft.