Something that no one has mentioned.
Lipo's have to be treated carefully.
Never use a lipo is it has bulges, or a torn wrap. In both situations put it somwhere fireproof like inside a pan with a lid, And then dispose of it correctly. Your local council tip will have a bin for them.
Never drop or pierce a lipo. It'll turn into a firebomb. If you do drop it, put it somewhere fireproof and keep an eye on it for several minutes. If it starts to get warm/hot walk away.
Always use the supplied hard case that lipo's ship in. Never leave one loose in a bag, or inside a gun. If they discharge too low or get damaged in a bag you will have a firebomb.
Never continue to use a lipo after the performance has dropped off. It is far safer to change batteries early and leave the used one charging in the safe zone than it is to try get a few more bursts out of one that has started to slow down. If the voltage gets too low you could have a firebomb, and loose the gun as well.
Provided you take care of the battery, charge it correctly with the correct charger, and keep it in good condition a lipo should have a good lifespan. And it will be safe to use. If you abuse them then you are inviting disaster with them.