batteries are just a little over a year old, AW IMR 18650's, never run down all the way I rotate 5 of them and they still all charge to about 4.19 on my meter. Last night I was vaping my Grand with door off, hit the button and noticed a little spark between tip of firing pin and the nipple of the battery lately I have not had consistent firing of batteries, I rotate battery with finger and find sweet spot to get a good vape, I have cleaned my Grand and used Noaalox. I know that I don't have 500 cycles on any of the batts. Is it time for new batteries even though meter says they are charging okay?? On the top of some of batts the silver is like scratched off and you see little black areas. Any help or suggestions are more than welcome. Thanks.