Hello! I'm new to the EDC flashlight world, and I just purchased my first awesome flashlight. I got a Fenix TK22, and I absolutely LOVE it! Anyway, I was reading the insert that came with it and noticed that it said to be "cautious" when using 3.7v 18650 batteries. I have two of these batteries that I've been using in my cheap-o flashlights, so I'd planned on using them in my new one. Should I be worried about anything? I don't want to ruin my new TK22. Thanks!