In AES' case at least, it sounds like this is their main value-add. According to the article they don't manufacture their own Li-ion cells, so my guess is they'

In AES' case at least, it sounds like this is their main value-add. According to the article they don't manufacture their own Li-ion cells, so my guess is they're more in the business of building and installing 'safe' enclosures that can withstand (and contain) catastrophic battery failure.