I have an LG 18650 3.7V 3000mAh 20a battery. I have a build in my RDA and it ohms out to .20 exactly. I want to run this on my nemesis mech mod that I recently received in the mail. with 3.7V the math adds up too 18.5 amps ad at 4.2V its 21.0. I this safe to use like that all? or should I go with a higher ohm. Also it takes ridiculous amount of time for anything higher than that to start firing.