As long as you don't massively over discharge them, don't charge on the wrong mode or fly with a dented battery you should be fine. If the battery shows any sign of swelling or dents/damage discontinue use and safely dispose of it. For added piece of mind might be worth making some sort of lipo safe. Army surplus ammo boxes work great if you drill an air hole in them to stop them bursting if you do have a lipo explosion. Although this is extremely unlikely if you have treated them correctly.
I had one old little 1S lipo swell, but it was really used. Just disposed of it (at the local battery disposal site). I've never actually had a lipo from any of my quads (Phantom 3, 210 racer, micro Inductrix) ever burst or flame out or anything.
I didn't think a lipo explosion could burst one of the 50 cal ammo boxes? Those things seem built to withstand way more than even a Phantom 3 battery exploding. Wouldn't drilling a hole in it allow the heat/flame/materials from a lipo explosion to escape? Just asking, never thought about the possibility of bursting one...
Hi Paul. No it won't burst one but it will reduce the pressure build up inside which would potentially ruin the rest of your batteries. Also make it dangerous to open. The small hole would let a bit of heatshrink out I guess but just keep it away from flamable stuff anyway and it will be fine.