deptrai:
afaik the root cause is still unknown. yet Boeing claims this is "not an interim fix but a permanent fix". I hope some more information is forthcoming.
Part of it seems more likely to be to fix fundamental flaws in the original design of
the battery subsystem.
If more modern technology with a higher than average risk factor is to be used, then
you need to go further than the usual due diligence and if anything,
over-engineer until enough in service experience is gained.
I'm sure they will make it work with LI batteries, as it is proven technology in other
areas...