Hello. Please try to forgive my ignorance in this matter.

I have several LED flashlights, a couple 18650’s and several 14500’s. Before my first purchase I was warned to buy protected batteries. I was told that the chip would prevent overcharging AND overdraining. Granted thus far I have only purchased UltraFire batteries, but I would think that ‘protected’ is ‘protected…’

I somehow left my torch on (a dual – 18650 light) and the batteries went dead. Now I thought that the whole point was that the protection chip prevented the batteries from going too low so that they could still be recharged. Well, they went completely dead and of course would NOT take a charge. Is this normal?

I also have used 14500’s in single-cell LED torches and these also ‘DIE’ if allowed to overdrain. I bought them on eBay and they were supposed to be protected. The only labeling on these batteries is the following: LCBTY14500 3.7V 2000mAh PRI.

By the way, I am using a NiteCore I4 charger. I had been told that this was a good charger to use and would work on a wide variety of batteries.

So, is this typical, or might it just be the cheap batteries that I am using. I thought the whole idea of buying protected batteries was just that.

Thank you in advance for any help – input – feedback you can offer.

Mike P.