But there you go, he has a very annoying habit of being right in such technical matters. However, even if he is wrong, 'my' fridge compressor would have to work twice as hard as the portable fridge in order to cool down twice the volume.
Having bought 8 meals worth of fresh meat in San Sebastian and given the portable fridge was full of beer, we put the meat in the big fridge and turned the temperature down to achieve a challenging 3°C. The portable fridge meanwhile was still running at a pretty relaxed 6°. I suspect you can see where this is heading, but at the time we weren't focused on our electricity consumption. At anchor in Pasito Blanco with both fridges running at about 6°C, the batteries were fully replenished by around 1400 each day and that was before fitting the new solar panel on the sprayhood. Performance in the marina at San Sebastian wasn't so good but our panels were shaded in the afternoon by a sports fishing boat moored on the next finger pontoon. I rather carelessly assumed that once at sea away from obstructions we would load up the Amps. This, as mentioned in a previous post, turned out not to be the case.
Anyway, back to the relative power consumption of the fridges. After measuring how long the compressor for each one ran and rested for, we (Mick) calculated that the large fridge was consuming 1.5 Amps an hour and the portable one, 0.5. Therefore, every 24 hours the big fridge is burning through 36 Amp hours, as against the portable fridge's 12! That's a total of 48 Amp hours, which is exactly the Amp hours we generated yesterday. That's better than we were doing when we had the flexible panel fixed to the sprayhood but doesn't give us any extra Amps for powering the water maker, water heater or Starlink.
So, we decided to adopt the blindingly obvious course of action: move the meat into the small fridge and turn its temperature down to 3° and turn the temperature of the big fridge up (to around 10"C). Unfortunately, because the two fridges have very different temperature control systems the switch over consumed a lot of power. The portable one has a thermostatic temperature control which resulted in the compressor running continuously until it got down to temperature. I don't know how the big one works but it takes a long time to equate the fridge temperature with the control setting. This means that its on/off cycle rate only changes slowly in response to changes made to the control knob. As a consequence, for some hours the two fridges consumed even more electricity than before! The net result being that by the time there was enough light to start the charging process again, the batteries were down to 43% of their capacity compared with the previous morning's 48%!
In other news, the AIS's remarkable performance of a couple of days ago has ceased and the antenna is once again only picking up transmissions within about a 10 mile radius.
We're making good progress and have been storming along all night at 6+ knots and surfing down waves at 8 knots which produces a loud prop noise as it rotates. As of 0845 on the 25th we had 314 miles to run to Sal in the Cape Verde. Our most recent weather information indicates a few days of light winds will follow our arrival in the CV area and so we'll probably stop off there and visit both the island of Sal which is the closest to our present position and Mindelo on St Nicolao.
Further calculations on the electricity consumption of the big fridge at the higher temperature setting reveals we are saving 12 Amp hours a day but we stll need to work out how much more the portable fridge is now using!
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