I use several 18650 IMR batteries in my rotation. About 5 AW 2000mah and three Sony VTC, shared between two mechanicals and a Provari in 18650 mode. There is evidence that if you use several batteries in a rotation that it will prolong the life expectancy of those batteries. Batteries benefit from some "rest time" between charging and discharging cycles. It also is benefitial to be using a quality charger.
A couple of those AW batteries are over two years old, and are just now starting to show their age by not holding a charge as long as when they were new. I never over-drained those batteries and never pushed them using lower resistance coils. Initially I was using a top-if-the-line Pila charger until one of the two bays stopped working a few months ago, and I then purchased a Nitecore Intellicharger i4 (financial circumstances were present not to purchase another Pila or an Xtar VP-1).
If you routinely push your batteries above 80% of their rated continuous discharge rating continuously, that hard use will negatively affect the expected life expectancy of those batteries. You'll notice a drop in mid-performance and capacity time during use in a mechanical mod.
If you don't have a way to measure the health of your batteries (ie voltage meter), I recommend purchasing one. A
510 inline voltage meter or
omnitester can be an important tool in your vaping gear. You'll insure that you don't over-discharge your batteries lower than 3.4 volts and that they come off the charger at 4.2 volts.
Take care of your batteries and they will take care of you for a long time.
