I'm planning on using this unit: 12V Peltier water cooler
for a portable heater/cooler. As such, I would need to run it off a battery. Based on what I've been reading, the best choice is a deep-cycle battery. Problem is, these are quite bulky and heavy for my application.
My questions are:
Is there a more efficient way to run a peltier module off a battery?
Given this module is 180W, I plan on running it off a 12V supply, this gives a 15A draw. If I was to plug it to a 4AH battery, would that mean the system would only run for about 20 min or would it damage the battery?
What kind of safety margin should I apply when trying to size the battery? E.g. 10%?
Thanks in advance for your help.