B787 battery
On the question of containing a problem within a cell. How many prismatic shaped pressurised aircraft are flying? The question on the backup internal protection is where the fault will be found. I cannot find the same sort of protection built into the prismatic cells as can be found within the cylinder type which has at least 2 methods to prevent this sort of trouble. What I would like to find out is if there was power being feed back to the batteries in both cases while this fault condition existed or if the process of disassembly was all within the battery case. i.e the one on the ground- was ground power or APU supplying DC to the batteries & I assume the A/C flying had the main battery powered from its charging source. By design, if the battery is fully charged it should be disconnected to protect the aircraft (imo). Li-Ion has no loss of capacity over any flight time of any aircraft. All the Aux. battery does is to start the APU when Ext, AC power is not available after which the AC alternators provide the systems power for normal ops. (maybe needed to "clean up" the DC but that could be addressed) There are several issues not just one cell failure that must be addressed before this aircraft is returned to service on just how safe the interface is to other components within the DC system. I hope all are identified.
Hopefully the fix is close.
Last edited by Jetdriver; 7th Feb 2013 at 11:39.