Just got my first mod with replaceable batteries (Voopoo drag.) I bought myself 4 Samsung 25 r batteries. They do not get warm when charging, I charged them on the lowest setting on an external charger. After firing the mod for a little while I popped the back off to see if the batteries were getting warm, since the tank was (smok tfv8) they weren't warm, but had a strange smell. It wasn't anything powerful, since I could only smell them with the cover off. It's kind of metallic, pretty sure I've smelled this on other batteries as well. Should I be concerned? For now I have removed the batteries and put them all in containers. If there was a vape shop near me I would take the batteries to them and ask for help, but unfortunately I live in a small town and this isn't an option - they took almost a week just to get here. For reference, I am using a 0.15 ohm coil and vaping at 80 watts. The batteries seem fine other than this smell, they aren't damage, don't get hot, and seem to charge, hold their charge, and do everything they need to. It would really suck to have to order new batteries, so hopefully this is normal and nothing of concern.. sorry for the long post, thanks for the help.