OK finally I got some information about what it would take to run my domestic 616kWh refridgerator on batteries.

So the fridge uses 616kWh per year so its energy rating tells me.
That breaks down to 1.69kWh per day or ~1700watts a day or 71watts per hour (71 watt-hours)
The Fridge requires 110Vac (110 Voltage alternating current) so a inverter is required to convert the DC current into AC running the DC current through a inverter means I will need to add 20% to my AC power consumption. Not sure why that is at this stage but I will find out why later.

So with the 20% in mind my fridge uses 85watthours to run.
To prevent damaging the battery I can use only 50% of the battery. This is called "Depth of Discharge" I should not let it drain bellow 50%.

8-D 225-255 Amp hours 12 Volt Used in Solar Electric Systems (= 2700 - 3060 wattHours ? )

If the 8-D battery was fully charged then I could run the fridge off it for 16hours beyond this time the battery would be more than 50% discharged (Should not discharge the battery beyond this point to prevent damage)

So how long would it take to charge the 8-D battery with a Solar Panel that outputs 1.2Amps @ 15Volts (18watts) 255/1.2 = 212hours to full charge this battery.




U1 34 to 40 Amp hours 12Volt 408 watthours would run the fridge for 2.2hours at which point the battery is 50% depleted (asuming a linear depletion)
40/1.2 33hours to charge the battery with a 1.2Amp 12Volt solar panel.
If I want uninterupted power to the fridge then I would need 15 solar panels


40watts 12Volt = 3.33 Amps 12hours to charge a U1 battery.

85watts 12Volt = 7.08 Amps 5.6hours to charge a U1 battery