Hi, I got some 1.5 ohm coil heads for evod because others were sold out. Actually I'm pretty happy with the 2.5 ohm coil it comes with. I vape it 3.7 - 4.3 volts. The 2.2 ohm may be great. Has anyone used the 1.5 coil heads and if so what do you pair it with? My lowest voltage device is 3.3 volts. Thanks!