18v and 20v"max" tool batteries are two names for the same thing: a 5 series configuration of li-on cells rated for 3.7v nominal/4.2v max charge. To my knowled

18v and 20v"max" tool batteries are two names for the same thing: a 5 series configuration of li-on cells rated for 3.7v nominal/4.2v max charge. To my knowledge none of these companies are manufacturing cells directly, and the only thing that is different between them is the shape of the connector, and the design/firmware of the battery management system. And the connectors are mostly not all that different, just variations on a theme designed to explicitly prevent cross compatibility. I don't see a compelling reason these couldn't be standardized, nor why this wouldn't lead to more innovation as manufacturers will have to compete on merit, rather than vendor lock in. Batteries are getting so good nowadays. Imagine if instead of everything needing its own special battery you just had a few quality packs that were interoperable with all your tools/devices/ebike/etc. *Edit: grammar