PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 31st Jan 2013, 18:11
  #342 (permalink)  
syseng68k
 
Join Date: Jun 2009
Location: Oxford, England
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fizz57:

A couple of thoughts....

Boeing's insistence on retaining the lithium batteries make me think
that they weren't chosen just for their size and weight, but that some
electrical characteristic (such a low internal resistance) make them
central to the design of the electrical system.
From info we have, the ability to fast charge LI might have been
attractive for some operational reason. Of course, they are much
lighter, but the reason may also have been that it is a much more
modern technology, with many benefits over either lead acid or
nicad. Well proven, so why not use it ?.

Secondly, I find the present focus and the batteries and chargers as
isolated systems to be pretty naive.
Perhaps, but that's where the fault originated and in fact, the
NTSB focus has been in that area since the problem surfaced, right or
wrong. The battery data log is in the charger and it seems strange
to me that they spent a week tearing batteries, down, subjecting
them to minute examination, when the event timeline to failure may be
elsewhere. Nasrudin's Lost Key, or what ?.

The engineers at the various plants involved can be assumed to be
reasonably competent...
More than just competent. Imho, the 787 is a revolutionary design,
in the same way that the A340 was when it was introduced. Technology
moves on and with any step change, there are far more risk than with
an incremental metoo design...

Regards,

Chris

Last edited by syseng68k; 31st Jan 2013 at 18:12.
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