Showing posts with label Lithium batteries. Show all posts
Showing posts with label Lithium batteries. Show all posts

Monday, March 14, 2016

Battery powered airliners.

NASA is funding research into them.  The idea is to carry batteries and an electric motor to drive (or assist driving) the fan section of a turbofan engine to produce thrust.  The greenies love the idea because it sounds so green, which is why NASA is spending money on the paper studies.  I wouldn't care to ride on one. 
   The artist's conception sketches show a fairly ordinary looking airliner with two big jet engines slung under the wings. 
    The article does admit that the idea doesn't really work until the batteries get about five times better than they are today.  Current lithium batteries store 150-200 watt hours per kilogram.  Everyone admits that the idea needs  batteries that can do 1000 watt hours per kilogram, five times better than today.  That is gonna take a while. It took 50 years to go from NiCad batteries to lithium for a maybe three times improvement.  At that rate of  progress it will take another fifty years to get to 1000 watt hours per Kg.
  Same issue of Aviation Week carries an article explaining that the International Civil Aviation Organization banning the shipment of lithium batteries on passenger airliners because of the fire hazard. 
   Your tax money at work.

Wednesday, June 19, 2013

Suits never learn

Aviation Week interviewed Boeing CEO Jim McNerney. 

Aviation Week:  "In retrospect, was the amount of weight you saved with Lithium Ion batteries a case of too much risk for too little reward?"

McNerney:  "It's not as simple as a weight-reduction-gone-awry conclusion because we get added capability from this battery, such as its capacity to quickly charge. In an all electric airplane, its a more capable battery. 

Yeah right.  Added capability is bafflegab.  All a battery can do is supply electricity.  As far "quick charging"  and "all electric airplane", all the battery has to do is get the engines started.  Then the aircraft runs off generator power.  As long as the battery recharges before the engines shut down at the end of the flight, all is well.

   In actual fact, some one at Boeing got carried away with the coolness of lithium batteries and did not bother to consider the fire hazard, which might not have been clear when the 787 was first conceived back in the late 1990's, but was pretty obvious by 2003 or 4.   Everyone else in the industry dropped lithium battery plans after they started catching fire in the 787.

Sunday, April 21, 2013

787 to fly again. FAA approves Boeing mods

I heard this on NPR yesterday.  It kinda got lost in all the Boston Marathon Bombers stories, but it is good news for Boeing.

Monday, April 15, 2013

Jump Starting the 787

Can you hear the holding of breath?  Boeing finished up the modifications to the battery and battery box on 5 April and sent the paperwork to the FAA.  FAA has said nothing, and has a hearing scheduled for 23-24 April on the adequacy of the Boeing fixes.  With $200 million airliners piling up at the factory, billions of dollars of sales, American leadership in the jet airliner business at stake, FAA is under a lot of pressure to OK the fixes and get on with it.  Even an Obama FAA  doesn't want to torpedo American airliner sales, at least I don't think they do.
   Boeing's fixes are not confidence inspiring.  They never did figure out what caused the batteries to catch fire.  They made a number of improvements to the battery, but since they don't know what caused the fires, they don't know if the fixes will do any good.  They are putting their real faith in a fireproof stainless steel battery box to contain any fires and vent the smoke over board.
   If the FAA approves Boeing's fixes, and more trouble occurs, they will look really bad.  And they know it.  FAA could decide that nothing less than ditching lithium batteries and going back to something tried and true, like NiCad, or even lead acid will do.  If they feel this way, they should have let Boeing know back in January.  To let Boeing waste three months, hold up the program for three months, is inexcusable.  If FAA want's to be hard ass, they ought to have had the guts to make their feelings clear, back in January.  If FAA announces "no good" next week, it will take Boeing another couple of months to do a battery change.
   Anyhow, the breath holding at Boeing will continue.

Thursday, February 28, 2013

Why have they not discovered a "root cause"?

For the lithium battery problem on the 787?  According to yesterday's Wall St Journal, the National Transportation Safety Board doesn't have anyone who knows anything about batteries or lithium, or even lithium batteries.  They are much more complex than those lead acid car batteries whose chemistry we learned in high school.  At least at my high school.
  Apparently both the Japanese and US safety boards have a single charred battery, taken from a 787, sitting on the bench, looking burnt.  The investigators have no clue as the how they came to catch fire.  And that's where it stands.  They haven't taken the batteries apart, analyzed the charcoal for dendrites, molten lithium, or whatever, 'cause they don't know how.
Gonna be a long time before those 787's fly again.