I really think it would be a lot harder than testing gasoline. For starters, with gas and other things like it, there is a supply chain which is pretty tight.

I really think it would be a lot harder than testing gasoline. For starters, with gas and other things like it, there is a supply chain which is pretty tight. If one supplier starts giving bad gas, you can blacklist them and move on. With batteries you'd have to test them after every single use, because you don't know what the last user has done to them. Then they need to be physically inspected, because a puncture or deep gouge or crack or something could cause big issues. Then their actual capacity needs to be tested some how. I'll admit that I've been outside of the battery ecosystem for a while, but years ago it wasn't all that easy to "spot check" a random battery to find it's health and capacity. Most devices would gain that knowledge about a battery over a few charge cycles. You need to make sure you know it off the bat, and you can't be wrong or I'll lose faith in the company and the tech. Then throw in the complication of different sizes, different shapes, different technologies, different requirements (this isn't just the "gas" part of fuel, it's also the "gas tank", so one size will never fit all), and now you are maintaining huge banks of different kinds of batteries all while charging them to the right amount without degrading them, and checking that users didn't run them in below freezing to almost 0 percent which would reduce the lifetime and aren't damaging them in any way which would be very unsafe. In an ideal world, it sounds like a great idea, but I just don't trust that it can be pulled off without making the user's life worse than if they didn't do it.