Hello all- I'm not very keen on electricity but am hoping this question is simple enough somebody might be willing to help out. I have a device that runs on 120v ac. Inside the device, the power supply converts the current to 1 12v-, 1 12v+ and 2 5v+. I'd like to remove the AC power supply and run the device off of a 12v battery. The device consumes 19w ac, I did a simple watts=volts*amps calculation and got 6 amps of 12v power...that seems high. Is that correct? Could I use a 12v battery with a 5v regulator to provide the 5v lines? Also any heads-up about mistakes I might make doing this conversion would be great. I can provide manufacturer schematics if needed. Thanks in advance for your help and my apologies for being a novice.