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Old 5th Feb 2013, 13:16
  #467 (permalink)  
RetiredF4
 
Join Date: Jun 2009
Location: Germany
Age: 66
Posts: 782
Is charging the problem?

Is the problem the charging of the cells?

Following the different threads the batteries are not used under normal ops, there schould be no charging cycle necessary. But nearly 150 batteries have been changed by the operators due to being in a critical low charging state. It can be assumed, that most of those low charging conditions were observed and most probably also took place on the ground, as otherwise we would have known about it earlier by some diversion reports. Both incidents happened on the ground or shortly after departure.

Something must have caused the unplanned discharging of those batteries, what we observe in the incidents is most probably the outcome of this prior failure.

Therefore forgive me when i dont think it is wise to look for the general problem in the battery or in the charging system. The battery should be protected against turning into some fireworks if for some reason a critical low charging state happens, but it shouldn´t drain either that low on a regular basis.

Therefore the problem has to be somewhere in the wiring and design of the whole instalation into the aircraft, an integration problem.

The questions being:
- What causes the draining of the batteries?
- When does the draining process start?
- Why are the built in provisions to prevent this low state ineffective?
- What systems have to be reengineered to prevent excessive discharging?
and at last
- How can the battery be protected against going fireworks.

Last edited by RetiredF4; 5th Feb 2013 at 13:23.
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