
Not just returns
Its not just the returns, its also the patent problems which prevent people without a strong stomach taking part. There are around 10-20 different components in a battery like electrodes, backing foils, separators, spacers, electrolytes and their additives etc etc and many are patented by different companies. To create a best-of-breed device you would probably have to licence from every owner.
Well this was the case 10-15 years ago when I was last involved.