Ok so that rules out phones, laptops and other devices that tend to get roughed up over time but I would still consider using it as energy storage for the solar panel on my house for instance.

As you have it isolated from the house in a specially built enclosure or garden shed it's less likely to get damaged and even if it is the damage can be manageable.

Then again in these cases it's more of a matter of how cheap it is vs the amount of energy it can hold and size doesn't matter a much.