I am a newbie and am ignorant to battery types, mAh, etc…I have no idea what any of it means. I am was about to purchase a FandyFire Rook and went to get the 14500 batteries for it and add them to the cart but then realized there were different types. I have a choice between 3.6V 900 mAh or 3.7V 900 mAh. They also give the option of a 3.7V 550 mAh. All batteries can be purchased either protected or un-protected. I don’t want to just assume that any of the batteries will work, nor do I want to order a battery that may damage the light or myself. Thought this would be the best place to ask. I have lurked here for quiet sometime but being a newbie, most of the technical details are over my head. BTW, can I just use plain energizer re-charge AA batteries and the charger I have for them? Thanks.