I need some help. Well, I'll be honest, I need a lot of help. I am trying to heat 1 liter of water running through a small tube that holds 8ml of fluid up by 12C, with a maximum temperature of the heater reaching 60C, and the entire liter needs to be heated within 30 minutes. In my experiments, the tube holds 8ml of fluid while passing along the 'heater' core, and will pass by the core in a total of 10 seconds. So 8ml heated by 12C in 10 seconds is the limiting factor and multiply that out to cover 30 minutes. The good news, I have managed to accomplish this feat by wrapping the tube around a curling iron rated at 80W x 110V. End result is 12C rise in output fluid, so I know the theory is completely possible. However, here's the kicker, the entire system needs to run off of battery power. So the 2 big questions are: what material should I use as the 'heater core' since I can not use a standard curling iron, and what battery system/configuration should I use (needs to be universal purchase ie, AA, AAA, D, C, 123, 9V, etc) Any help would be greatly appreciated both to my personal safety as I tinker in the garage, and to my wife's sanity as she watches me play with water around plugged in curling irons. :) Thanks in advance. WS.