PPRuNe Forums - View Single Post - 787 Batteries and Chargers - Part 1
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Old 8th Mar 2013, 03:44
  #857 (permalink)  
saptzae
 
Join Date: Aug 2011
Location: hong kong
Age: 59
Posts: 93
Confirmed no NVM / no logging of details.

Scenario:
  • 10:21:01 Primary failure - cell short of #3
  • 10:21:04 Secondary failure - Large current (45A) for 3 seconds overcharging and damaging remaining 7 cells and driving them into _electrically_ induced runaway. TBD whether this is due to charger not shutting down or parasitic connection to a power source (Main Bat).
  • 10:21:27 Tertiary failure commences. Electrically induced runaway of #1, #2, #4, short of cell #6 along the way feeding more heat into #5, #7, #8. Smoke and fire.
TBD what caused Primary failure.

I suspect that NTSB schematic is simplified. It appears that there is no cell balancing. This would be ridiculous because it would lead to cell overvoltage and to Primary failure.

Last edited by saptzae; 8th Mar 2013 at 04:27. Reason: Expand
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