I am currently using the Samsung icr18650 2600mah battery that the evic uses. The problem I'm having is that 1. it comes off the charger only at 4.1 volts. and 2. I've noticed a significant decrease in power and vapor production once the battery life hits around 3.7-3.8 volts. My question is would using an IMR battery like the aw imr instead of an icr make a difference here?