I will say of all the batterys i have tryed AW, IMR, PANNYS, XXXXFIRE these samsung 1600mah 18amp markings are INR18650-15Q rock hard, dont let the 1600mah rating trick you these batterys last longer than my 2200mah. These batts hold their voltage really well for low ohm gennys and hold steady voltage for long drags on the PV
have you ever tried the MNKE imr's? i personally use aw imr's, but heard that the MNKE bats are better for higher amps.