I work in a mill and it's a pretty rough environment. I was thinking about getting a mechanical since I'm constantly worried about trashing my MVP or dropping it. I was looking at the K100. I'd like to use a tank with a 2 ohm coil. I have an iclear 30s and kanger Protank 3. The part I'm confused on is battery selection. I usually work at least 10 hours a day. So if I could get by without carrying extra batteries that would be awesome. What specific battery would be best?