I made a very effective Peltier Cooler for my ZWO astro-camera using a cheap ($2) 12 volt / 60 watt Pelter TEC and a CPU "heat pipe" cooler.
Even though both the TEC and the heat sink fan are rated at 12 volts, I run them off a 6 volt battery supply. (It's actually a 12 volt / 7.2 amp-hour SLA battery running through a 12 v - 6 v "buck converter" - another eBay buy for about $5.)
The TEC will pull 3 to 5 amps at 12 volts. At 6 volts, the heat-sink fan runs more slowly and quietly (and vibration-free), and the TEC is only pulling about 1.5 amps at initial cool-down, and the current drops lower as the TEC reaches thermal equilibrium, so my 7.2 amp-hour battery will last for several hours. I'm getting a Delta-T of about 24 degrees Celsius at the image sensor.
Some info on my build here:
http://julianh72.blogspot.com.au/201...-asi120mc.html
and here:
http://julianh72.blogspot.com.au/201...ng-on-cpu.html