chaosmagnetWhich protected cell did you use? I don't think anybody has had one that would fit in the light...tolerances (by design) are too tight and I don't think anyone makes a "short" cell to accommodate the added protection board and stay within standard length. You can put a protected in here and start to screw the head/cap on but the gap caused by the longer cell will prevent contact on both ends with the sleeve insert, so no complete circuit.