Is my mod draining my battery when I'm not using it?

[Triple7]

Hey so I have this problem where I plug in a fresh battery I use it once and then lock it and set it down. When I try to use it again, the battery is completely dead. What's going on?? It makes no sense I AM using a pretty ....ty old clone mod that's already failing but seriously? A few hits and its dead?

I'm using those yellows 18350s

 

[xyanide]

Maybe the batteries are the problem. I once used really bad 18350s that wouldn't even get me to fire because they dropped the voltage so badly under load.