OK, so 10 watts for 24 hours is 240 watts, or 20AH. You should size your battery at least 2x the # of AH you want to draw from them each cycle, if you want it to last any length of time, So you should be looking at a 40ah battery minimum. At the smaller size of things, you may not be drawing at the 20h rate, so the rated capacity of the battery may be less than what is specified for the 20h rate.
Then, lets look at the solar side of things. 18 watts is 1.5a@12v So for 5 hours, that is 7.5 hours. With OPTIMUM placement of the panel, in a place that gets full sun for 5 hours, you may get that. 7.5 ah. So you are drawing out 20ah each day, and depositing 7.5ah. This is a deficit.
Assuming your 10w draw (and I have not confirmed this on our unit) the I would think a 55ah battery and a 50 watt panel would do the trick - or my math is off (and that is certainly possible).
I assume that you are looking to put this on a small boat, perhaps one without an engine? Tell us more.
Chris
Quote:
Originally Posted by ericb  Chris,
I've been doing some research, and theoretically it should work.
I only want to run the cooler at a little above zero (C). The stirling cooler should use about 10 watts to keep everything at 3 degrees C while at 25 outside. At temperatures lower than 25, the cooler should switch off from time to time. etc.
If I'm wrong, I'll either have to pick a larger battery/panel or set the cooler at a higher temp.
I was curious if any other people have any experience with such a minimalist approach .
Eric. |