Lyman.
I take your point about stresses at the folds and the quality control required to construct a device that works as advertised.
However, as single units these batteries (cells) appear to work well in other environments.
My understanding from previous posts, is that these battery 'cells' have been used extensively as individual units for many years without too many problems.
Bearing that in mind, I don't see how the construction of these individual 'batteries' can be at fault. It must be either the way they (all eight of them) interact as a group, whether that be thermally, electrically or physically, or there is a problem with the way they are being used (charged/discharged). Or indeed a combination of all these.
