Yuasa Japan make the cells.
Are you sure that they make the battery assembly?
Are you sure it isn't Thale that builds the "package"?
Although the cells are probably failing, I'd bet they are not the cause of the failure.
I'll bet it turns out that the cells are just fine.
It's obvious the
were not name brand
used here on Earth.
More important to
ask is whether the
lithium ion batteries
are rechargeable or
throw away batteries.
I recommend that
Boeing switch to
long expiration date.
There will always be the question of the wisdom to go to a different and more exotic technology, but the risks are weighed against the benefits. When you think of the 787, the first "exotic" technology that comes to mind is the composite structure. Some level of use of composites had already been in place, but Boeing jumped past simply applying this to some sections and made almost the entire aircraft out of it. Li-ion batteries have been around since the 1970's with "go for it" consumer applications starting in the 1990's. It is now all very common. Lead Acid dates back to 1881, Ni-Cad to 1956, and NiMH was introduced commercially in the 1990's. Li-ion batteries reduce weight and volume which are always at a premium for fuel efficiency and customer salable space.
Batteries go through charge and discharge cycles and some kinds of cycles are benign and other cycles wear them out faster. The lead-acid batteries deteriorate with micro-cycles (less than full cycle), Ni-Cad has a "memory issue", and NiMH batteries have a high self-discharge rate ("stand loss") as well as are only good to a 50% depth of discharge (DoD) (i.e., worth a half of use). Remember that we were told to always take Ni-Cad batteries down low in charge and then fully re-charge; don't partially charge as that changes their performance. Li-ion apparently are more tolerant when cycled in any manner that is necessary and they have an 80% DoD capability -- they are superior in performance.
The problem with Li-ion battery cells is that they are "fussy" when it comes to the voltage that is applied across the cell when charging. The other batteries' cells are less fussy. So cell voltage regulation (balancing) is critical. That is the job of the charge controller as well as any electronics integrated into each cell. Cells are strung into a series and "share" the charge from the controller across the entire string. Problems arise when a cell performs differently such that higher charge voltages are applied to that cell or the other cells than is tolerable. The older technologies naturally tolerate the overcharge. Li-ion cells do not like overcharging at all and will fail. Voila! Fire. The charge control at the cell and pack level is critical.
So, Boeing will fix this. It is fixable. And it works extensively all over the place in many applications. And it is desirable to continue with Li-ion and not revert to antiquated technologies. The satellite industry has moved in this direction and it makes sense for an aircraft such as the 787 with its extensive use of electrical/electronic systems to employ this weight saving technology. It just has to be done right.
Yuasa japan makes them they have been making lead acit batteries for years for motorcycles and these were very high quality I can attest to that. However the properties of lithium ion batteries are entirely different and of course these batteries have to be rechargeable.