With completely wireless earbuds, the rule is: when the battery fails, they have to be disposed of. Not so with the Fairbuds, that allow you to replace batteries in just a few seconds. Combined with a repairable design, the earbuds should therefore have an extremely long lifetime.
Yes. I just replaced the ones in my wife’s Sony earphones by following a step by step guide on ifixit. Cost me $15 for the batteries including shipping, and they’re not even any sort of exotic type or size.
Edit: okay just read the article. Guess these are a lot more convenient to replace than the Sony ones.