Quote from
sb_sfo:
"But I noticed one thing- you seem to be under the impression that 777s have more than one main battery. The ones I work on have a main and APU battery, and unless you want to count the fuel spar valve batteries, I know of no others."
You are right, I did post that the B777 had two main batteries, plus the APU one. My Google search for "B777 electrical system" had produced a nice clear schematic with two, which I now see is for a generic system. Thanks for setting me straight on that, and I look forward to more info on the B787 points.
(EDIT)
Have now found and amended my
post. Looks like all currently-operating Boeing types have one main battery, plus a dedicated APU battery?