PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 9th Feb 2013, 21:54
  #597 (permalink)  
RR_NDB
 
Join Date: Feb 2011
Location: Nearby SBBR and SDAM
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On assumptions

Hi,

New batteries:

1) Maintenance free: Dozens had to be replaced prematurely
2) High MTBF: Dozens failed and 2 grounded the fleet in ~ 100,000 hours
3) Heat (cell) is not an issue: Thermal runaway created smoke and fire.
4) Safe to be located in EE bays:
In one case Logan firecrews
spent more than one hour
to control a fire. In TAK the
smoke was visible by ATC. A
non designed fuse (ground
wire) opened and probably
saved the day. (With the
prompt landing.)
5) Algorithms are capable even
to "avoid" individual cell
temperature monitoring
probes: A shorted cell
triggered a thermal
runaway. (BOS) A super
heated cell (# 3) led to a
short circuit of 12 V to
battery case as mentioned
(model) in an earlier post.

Other assumptions were made...
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