What you need to do is step down to a single 17670 battery which will bring you down to 3.7 volts then try an
LR atty either 1.5 or 2.0 ohm , this combination will put you closer to 5 volt and will make your life easier. On the
plus side you will get longer battery life, use less juice, get longer atty life. and do away with the burnt taste., and be able to take 6 to 8 nice draws off your Prodigy V3.1 before re-dripping.