Cool boxes

Not sure that is worth doing as it takes so long for the heat sink to cool.

I did a lot of trials at home with a water filled Peltier cooled box. Yes it took a long time to cool down but I was able to demonstrate that warming up when I switched off the power was much slower with an extra inch of insulation and slower still with another inch. I was able to switch off for an hour then back on again with no significant warming up. Admitably a cool box full of water is a very large mass but most of cool box is full of either amber liquid or white wine anyway!!
 
My experience using a Peltier coobox when camping is that ambient temperature / ventilation is the all important factor. Recently over a very hot 4 days I was moving the box out of the tent (too hot) during the day but still having to move it several times for best shade.

Incidentally, I have found that one of those cheap 'universal' computer PSUs from ebay (about £5) are ideal for powering a 12v coolbox from 230v. Set it to either 12v or 15v and see which it is happiest at.
 
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