18650 to C-Cell positive terminal adapter

thingiverse

These objects are simple adapters that allows placement of a standard 18650 cylindrical lithium-ion cell into a C-cell battery tray. In a tray which usually houses two C-cells in a row, use the long version to substitute a single 18650. In a tray which usually houses three C-cells, two 18650s may be used with on normal adapter each, but BEWARE! Two lithium cells supply substantially more voltage than three C-Cells, and they will cook electronics if not used correctly. An additional spacer ring for the negative terminal is advised. More variants are forthcoming.