I started charging the 14500s when I had a doubt - protected batteries have a circuit that prevents over-voltage, any charger would have one too. Won't they sort of 'interfere' with each other ?
Say the battery stops charging at 4.1V while the charger normally stops at 4.2V - the charger will never "see" 4.2V, right ?
The pcb will kick in stopping the charge, you can always put the cell back on the charger but trying to get to 4.2volts might cause the cell to miss terminate or the protection circuit might not kick in causing overcharging of the cell. An ideal charge would be around the 4.15-4.18 range while the cell never reaches 4.2 the cell will have more longevity. I have a couple of those cells and there nice, may not fill all the lights you have though because there longer then AA's.
The LED is supposed to turn green when fully charged. After 7 hours it was still red/orange, but the battery had cooled down. That's when I began wondering whether the protection in the battery was interferring with the charger.
Nope it should'nt, all the circuit does is stop the flow of current when the voltage is reached for the cell, you might want to try another cell and see what it does, if it also does the same with that cell i would recommend you either take the cell out after a couple of hours and check the voltage with a dmm.......the cell should be at or around 4.17-4.18, remember anything voltage over 4.2 is harmful to the cell.