I have an old incandescent flashlight which uses two AA cells. I prefer to use NiMH rechargeables. I would like to replace the incandescent bulb with an LED. It does not need to be bright at all; there is no heatsinking and the flashlight is rubberised so it mustn't be so bright that heat is a concern. My problem is that all the drop-in incandesent-to-LED upgrades I've found assume alkaline batteries and don't even seem to function below 2.8 V which isn't even good for alkalines IMO. They're basically just an LED and no circuitry to regulate the current or increase the voltage. Does anyone know what I can do or get to replace the incandescent with an LED? I don't mind making it myself but it needs to stop at 1.8 V so I don't risk reversing the voltage on one of my rechargeables which a joule-thiefy thing won't do. Again, I don't want anything flashy - I just need it to not walk into things. I'm thinking a current draw of 30 mA. Thanks!