DIY Fridge?

[Rendelf]

Hello peeps,

 

A little add for any future readers...

 

Though my evapo-cooler is still in its production stage (ran out of expanding foam!) I have recently acquired a small A++ chest freezer (£30)

 

It's a standard-ish height, but half the width. This means it makes a perfect worktop when closed. I've added a thermostatic capillary switch from BimbleSolar (£5). The unit is rated at 160W, which is about double what a new unit uses.

 

So far so good. In theory, it can pull up to 13-15A at max. However, it has an adjustable input (from min-max), which I presume means it isn't using its full rating (as it's set to min). once the temperature has been reduced to around 5 degrees, it seems to cycle around 5 minutes out of every 60. The insulation is excellent, and I can set the thermostat to 10 degrees to just keep veggies cool, if needs be.

 

So far, haven't noticed the batteries complaining at all!

 

Currently it's running on a 2000W inverter.

 

I have a 200W inverter. I'm wondering if I should:

 

a. Put the inverter by the freezer, and let it pull 12V about 15 meters through 15mm2 cables, or

 

b. Put the inverter by the batteries, and use a 12V relay to operate it, through about 15 meters of 5mm2 cable

 

 

Will I loose more energy by operating the relay constantly, or by using perhaps 10A@12V over 15M of 15mm2 cable?

 

Edit: Just realised that all I need is a relay that is always open, and only uses power while the thermostat is operating it.

Edited July 29, 2016 by Rendelf