I dropped my Ultra Fire HD-2011 from a 5 foot high self early this morning onto a tile floor. The light went out and I thought …. no way will it ever work again. Believe it or not I put another 18650 battery in and it fired right up. Now the problem is the original battery that was in it when it fell will no longer work in any of my 5 18650’s. I have measured the voltage on it and it is putting out 3.4 volts but it will not work in “any” of my flashlights. The battery is a Samsung ICR18650-30B 18650 3000mAh Protected Rechargeable Lithium Battery. Any advice…. I’m all ears?
sounds like the protective circuit got f’d up in the impact of the drop. you could always rip the circuit off and make it an unprotected cell but might want to wait for more people to chime in and see if there is another fix
Could it be it’s not making good contact in the lights?
I don’t think so…. I’ve interchanged 3 different lights and batteries. It will not work in any of them. Also all the batteries work in the flashlight that fell.
After charging the battery for approx 2 hours, I installed the battery and there was a very quick flash of light but then nothing.
To make a long story short, “right or wrong” I tried to reset the PCB with another fully charged battery, + to +, - to -, that didn’t work, so I tried a 6 volt, that didn’t work, then a 9 volt, that didn’t work, the a very quick touch with a 12 volt…… that worked in the flashlight but it would not charge in the charger. I took the PCB off the top and bottom of the battery, charged it to 4.2 volts and it is now working fine as far as I know. I more than likely did some damage to the battery but only time will tell. Thank you all for your suggestions. I hope this may help someone else.