IMRs are pretty safe to use without a fuse as long as you understand the amp limit of the battery and what you are drawing through your atomizer. You don't want any shorts either. First sign of a battery issue is going to be heat. If you have a short or are over discharging the battery it will get hot VERY fast.
Too tired last nite I guess. I did get my K100 yesterday and will be doing the sanding thing later today on it, so I will post the results later for the K100. But I expect the same results.
