This thing lets you design an adapter to exchange different kind of batteries!The STL here is for an A13 zinc/air battery in place of a LR44 (or SR44), because it happened I had these around, otherwise useless to me.Make sure that the voltages are compatible though! (here I have 1.44 volts instead of 1.55: lower is safe but may not work properly)Battery diametersFor other kind of batteries, just use a caliper or check here: http://en.wikipedia.org/wiki/List_of_battery_sizes#Button_.2F_coin_.2F_watch_.2F_micro_.2F_miniature_cellsThen use the customizer for your own battery sizes: http://www.thingiverse.com/apps/customizer/run?thing_id=31421Or you can use the excellent Openscad tiny application, it should be very easy even for non-programmers: just set your diameters in the corresponding fields in the beginning of the scad file, then hit F6, and through the menu, go to Design / Export as STL. And you are done :)The script handles the case when the replacement battery height is smaller than the original one. But, well, if what you have is bigger or taller battery then the original, this wont't help... :) You still could redesign the thing that holds your batteries of course but this is another story!PrintingBe sure to print both slowly and at the lowest temperature you can, else you'll melt the whole thing. I printed at 210 instead of 230 degrees, and it was still a bit too hot (see the upper part of the thing being printed for example).The settings here were:My nozzle is 0.4mm BTW.