backtop


Print 18 comment(s) - last by Sivar.. on Feb 5 at 12:15 PM

The investigation is ongoing

The National Transportation Safety Board announced over the weekend that x-rays and CT scans of the lithium-ion battery pack that caught fire in a Boeing 787 Dreamliner in Boston recently was not overcharged. The battery in question powered the plane’s auxiliary power unit and the investigators have disassembled the battery and are still investigating some of the individual battery cells.

The battery fire has led airlines to stop flying the 787 planes around the world. The NTSB investigators have also said that they have examined several other components from the aircraft including battery management circuit boards and associated bundles of wire. The investigators also intend to continue testing components such as the battery charger and battery management unit.

The investigators have announced that the plane's flight data recorder indicates that the battery never exceeded its design voltage of 32 volts. The FAA issued a directive last week that the Boeing 787 Dreamliner should not fly until any problems with the battery packs are resolved.
 
Boeing has announced that it will halt deliveries of the 787 to customers while it works with the FAA to solve the battery issues. The batteries at the center of the investigation are lithium-ion units manufactured in Japan by GS Yusana under a subcontract to a company called Thales.

Source: CNN



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Just a guess
By Samus on 1/21/2013 1:29:02 PM , Rating: 2
I agree. And not just vibration, but pressure and temperature extremes, all of which are not well tolerated by lithium (ion) cells. Lithium Polymer would be better suited but I'm sure Boeing chose Li-ion because of its more 'mature' industrial status.

All I can say: my Milwaukee 18v lithium drill battery only took a few drops before shorting out and failing, whereas my R/C Truck LiPo pack has taken impacts so harsh it has been ejected from the vehicle into a concrete wall, and it continues to function fine.


RE: Just a guess
By nafhan on 1/21/2013 2:15:51 PM , Rating: 1
quote:
not just vibration, but pressure and temperature extremes, all of which are not well tolerated by lithium (ion) cells
While that makes sense, one would assume that Boeing did a bunch of testing that exposed the batteries and the entire aircraft to those conditions - repeatedly. I'm very interested in hearing how they missed this problem in their testing.


RE: Just a guess
By Keeir on 1/21/2013 2:44:57 PM , Rating: 4
quote:
but I'm sure Boeing chose Li-ion because of its more 'mature' industrial status.


Battery choice was made in 2005-2006 timeframe and a contract was awarded. This was a multi-level contract in that Boeing (US) contracted Thales (France) who contracted Yusua (Japan).

This was before the Sony issue. At the time the initial choice was made, there was little conrete real world evidence that Lithium Cobalt Ion batteries were a potential problem. Once the contract is awarded, changing the details of the contract mean serious money. Without a "proven" safety risk, Boeing (management) wouldn't force Thales to change it's supplier.


"People Don't Respect Confidentiality in This Industry" -- Sony Computer Entertainment of America President and CEO Jack Tretton

Related Articles













botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki