Lithium Ion Battery Fires ground entire Boeing 787 Dreamliner Fleet

Posted by PITHOCRATES - January 20th, 2013

Week in Review

The big drawback for electric cars is range.  For after a battery powers all the electrical systems (heating, cooling, lights, etc.) what charge is left is for going places.  And if that place is more than 30 miles away few people will feel comfortable taking a chance that they will have enough charge to drive there and back.  Unless that trip is to work where the car can recharge for 8-9 hours while at work.

Range anxiety is the greatest drawback to an all-electric car.  For if you run out of charge there is only one way to get your car home.  With a tow truck.  For you can’t walk to a gas station and ask for a can of charge to pour into the battery.  Charging needs an electrical source.  And time.  So the Holy Grail of the all-electric car industry is a battery that can hold a lot of charge.  But is small and does not weigh a lot.  And can be recharged in a very short time.  Right now that Holy Grail is the lithium ion battery.

But there is a cost for this Holy Grail.  There is a lot of chemistry to do this.  Chemistry that can produce a lot of heat.  Catch fire.  And explode.  Which has happened in some electric cars.  As well as in some airplanes (see Bad Batteries Seen as Best Case for 787 Overcoming Past by Susanna Ray, Alan Levin & Peter Robison posted 1/18/2013 on Bloomberg).

Other aircraft bleed air off the engines for a pneumatic system to power a variety of critical functions, such as air conditioning. That diverts power from the engines that they could otherwise use for thrust, and means they use more fuel.

With an electrical system for the jet’s other needs, the engines become much more efficient. The 787 uses five times as much electricity as the 767, enough to power 400 homes. To jump- start a so-called auxiliary power unit that’s used on the ground and as a backup in case all the plane’s generators failed, Boeing decided on a lithium-ion battery because it holds more energy and can be quickly recharged, Mike Sinnett, the 787 project engineer, said in a briefing last week.

Those capabilities also make lithium-ion cells more flammable than other battery technology, and they can create sparks and high heat if not properly discharged. Chemicals inside the battery are also flammable and hard to extinguish because they contain their own source of oxygen, Sinnett said.

A couple of battery fires have grounded all Boeing 787 Dreamliners.  The last commercial jetliner to receive such an order was the McDonnell Douglas DC-10.   Which happened after an engine came off while taking off at O’Hare International Airport in Chicago.  Due to a maintenance error in changing out the left engine and pylon.  Causing the plane to crash.  After investigation they found the slats did not mechanically latch into position.  When the engine ripped out the hydraulic lines the slats retracted and the wing stalled.  The plane slowly banked to the left and fell out of the sky.  Killing all on board.  The DC-10s were grounded worldwide until the hydraulic lines were better protected and the slats latched to prevent them from retracting on the loss of hydraulic pressure.  Now no 787s have crashed.  But few things are deadlier to an airborne aircraft than a fire.  For there is nothing pilots can do other than to continue to fly towards an airport while the plane is consumed by fire.

Stored chemical oxygen generators in the hull of ValuJet Flight 592 were stored improperly.  They were activated.  Producing oxygen by a chemical reaction that generated a lot of heat.  The heat started a fire and the oxygen fueled it.  Once the pilots were aware of the fire they turned to the nearest airport.  But the fire consumed the airplane and fell out of the sky before they could land.  Killing all on board.

Fire on an airplane rarely ends well.  Which explains the grounding of the entire 787 fleet.  Because these lithium ion batteries run very hot when they make electricity.  And they can generate oxygen.  Which is the last thing you want on an aircraft.  However, both Airbus and Boeing are using them because they are the Holy Grail of batteries.  They’re small and light and can hold a lot of charge and nothing can recharge as fast as they can.  Which is why they are the choice for all-electric cars.  Even though some of them have caught fire.  This is the tradeoff.  Smaller and lighter batteries are smaller and lighter for a reason.  Because of powerful chemical reactions that can go wrong.  So to be safe you should park your electric car outside and away from your house.  In case it catches fire you’ll only lose your car.  And not your garage or house.  Or you can stick to the gasoline-powered car and not worry about battery fires.  Or range.

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