Addressing battery safety once again.
If your batteries are dented in any way, shape, or form; scratches or tears in the wrap; missing insulator ring; arc marks or burns; stop using them IMMEDIATELY. Basically, if your batteries look like the ones in the photos attached (first two photos credited to Simon Stokes of Wild Predator in North Bay, ON), STOP USING THEM, and dispose of them properly (i.e. recycle, not in the garbage, or the street!!).
If your batteries are in excellent condition but have a tear in the wrap and/or have a missing insulator ring, bring them by to have the insulator replaced and/or have the battery re-wrapped. We do this **for free**.
Additionally, NEVER EVER EVER carry your batteries outside of a case, in your pocket, purse, bag; or install them in your device with any tears in the wrap or missing insulator ring, as you risk shorting them out on the battery tabs, keys, change, or anything conductive. Li-Ion batteries can react violently to a short circuit, either by venting noxious gasses and electrolytic fluid, flame, and in some cases depending on the chemistry, explode.
Additionally additionally, do not tear apart battery packs (drills, laptops, etc.) and use the batteries from these. Even if you are knowledgeable of battery brands and models, and know that they are a safe brand/model to use, you have no idea how many charge/discharge cycles those batteries have been through. Not to mention removing these batteries can be dangerous as they are generally connected in a series/parallel circuit, and disassembling these packs puts you at risk of injury as you risk causing a short circuit.
Do not become another statistic for the media to get ahold of.