Would it be something to revive some of the list of requirements we used for the Sofirn C01?
Including the vampyr circuit and the potting. Excluding the things that can be missed, like trits.
My idea would be a basic AA light, because people throw away millions of half-spent penlight batteries.
(no honey, we’re going on a holiday and I don’t want to risc getting stuck with an empty you-name-it).
Maybe they can get “fresh” half-spent batteries for free, every time they turn in a set of fully bled-out batteries.