I'm excited- building batteries seems to be the most practical way to go to get below the expense of a bottle battery- at least until more "10 mile" half batteries come along. At 63, I may not get there much, but learning stuff about the batteries, and they have great parts now that snap the batteries together at both ends and to each other and also metal strips that need no soldering. I'm interested in keeping things small and light and most of the batteries out there are large and heavy bottles and canisters. It would be nice to be able to simply replace the cells periodically and avoid the large cost of heavier e-bike pre-assembled batteries. Thanks.