Battery Circuit Design
I am trying to take the discussion on a different route here. Having worked on several Boeing and Airbus aircraft including A380, there is a point worth noting. If Boeing is making a new aircraft and require a new battery circuit design, looks like, they just call the guy who designed the previous aircraft DC circuit. He pulls out his old drawing and makes a few changes and presto we have a new design. I am not saying that is exactly the way it was done here, but when I compare B747 to B777 thro to B787, it would appear so.
Airbus designs are no different. The battery circuit design is the same on A300 to A310 to A330 to A340 to A380. For A350 schematics are not yet in the public domain but it will not be very different. But the design is more clever on this side of the pond.
So why am I bringing this point here? You should wonder how Airbus has managed to quickly switch back to Ni-Cad for A350, when the heat is on LI. With Boeing when the aircraft became bigger or system demand increased, the battery size also increased and we have now a massive 70AH battery that can supply 150A peak load. It is just 50AH battery on larger B777. They have just failed to consider other options when the demand increased. failed to think out of the box.
Look at Airbus design. From A300 to A310 to A330 to A340, they have 3 batteries that can be switched as the load demands and each one of them is smaller in size in comparison. Each battery has it's own control, which disconnects that unit in case of a defect. So when they designed the A380, they used 4 batteries, again switched in parallel if the load demands. For A350, I am sure they had 3 small LI battery which they can quickly change to Ni-cad at the blink of an eye. Clever design and config.
Why Boeing is not thinking of splitting the battery into 3 or 4 units? That way the heat build up and the danger to the air-frame is minimal. I know this will be time critical for certification etc.
Think about it, instead of trying to create a meteor shower in the sky with a burning LI battery. ( I am neither American nor an European - so don't think that this is start of spat who is superior across the pond).