I keep reading how people say they won't let their batteries go below 2.7v, 3.3v, etc.  And to never let it completely drain out.  
1. How exactly do you tell when a battery gets to a certain volt level if you use nothing but mech mods?
2. Is it OK to drain a battery completely?
3. I have an Nitecore i4. Should I stick to that or would anyone recommend something better?
TIA!
	
		
			
		
		
	
			
			1. How exactly do you tell when a battery gets to a certain volt level if you use nothing but mech mods?
2. Is it OK to drain a battery completely?
3. I have an Nitecore i4. Should I stick to that or would anyone recommend something better?
TIA!
 
				
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		