I was also going to connect the fan to the power switch and battery ground. I salvaged the fan from an old Dell laptop I had kicking around (I'm a computer tech). But a good place to find computer fans is Princess Auto if you are in Canada- they have all kinds of that stuff in their salvage section. Barring that, I'd look at a CPU cooling fan from a computer shop. Be carful on voltage- you want a 5 volt fan, not a 12 volt. And you'll need a resistor in series with the fan to drop voltage.

The way to figure out the needed resistance is figure out the voltage drop you want (2.5 volts or so as as full battery shows at about 7.6 volts fully charged), the current draw of the fan (on mine it's 0.05 amps), then divide the voltage by the current- 2.5v/0.05 amps. This gives me 50 which is ohms. A great resistor color code calculator is at http://www.dannyg.com/examples/res2/resistor.htm.

Man, it's almost as much fun customizing your tank as it is to run it!


Dmon1996