Electrical: DC AC Conversions - Efficiency
I am an Electricity Novice:
Assumptions: Boon-docker - does not use shore power, uses Solar Panels and Batteries, or generator. Refrigerator does not have propane option...electric only, AC or DC.
Question: what is the most efficient method to power a RV Danfoss Compressor Refrigerator? Do I use the 12V battery direct (DC) to Refrigerator or 12V battery to Inverter making 120V (AC) to Refrigerator?
If a device can run on both AC and DC, does the rated input power (in Watts) of the device always remain constant when doing the Watts = Amps x Volts equation.
Below is the specification given for the Refrigerator. Is this enough information to figure out the Amperage it will consume from my batteries? Assuming Rated Input Power for the device is the same for AC and DC, then Amps used if I ran the energy from my battery through my inverter changing it from DC to AC, would be .54 Amps (Amps = Watts/Volts) 65W divided 120V = .54 Amps. And if the refrigerator compressor ran for one straight hour I would consume .54 Amp hours from my battery (not counting the roughly 10% energy loss from the Inverter process). If I ran the energy directly from my battery to the refrigerator and the watts or rated input power stays the same, I will be using 5.42 Amps (65W divided by 12 Volts). So I use about 10X the energy from my battery going DC instead of running it through an inverter to produce AC.
What am I doing wrong here? I’ve always heard, if possible, it is much more efficient to run a device directly from the battery (DC) instead of running it to an inverter that changes it to AC to run the device. My calculations above prove the opposite.
Assuming my calculations are incorrect, how does one figure out how many Amps a device will or can use under maximum draw for an AC setup versus a DC setup when the device is capable of doing it either way? Is the data provided below enough to make that calculation?
Input voltage (AC) 120 V
Input frequency 60 Hz
Rated input power (AC) 65 W
Input voltage (DC) 12/24 V
Thanks for helping this beginner.
Tim
Assumptions: Boon-docker - does not use shore power, uses Solar Panels and Batteries, or generator. Refrigerator does not have propane option...electric only, AC or DC.
Question: what is the most efficient method to power a RV Danfoss Compressor Refrigerator? Do I use the 12V battery direct (DC) to Refrigerator or 12V battery to Inverter making 120V (AC) to Refrigerator?
If a device can run on both AC and DC, does the rated input power (in Watts) of the device always remain constant when doing the Watts = Amps x Volts equation.
Below is the specification given for the Refrigerator. Is this enough information to figure out the Amperage it will consume from my batteries? Assuming Rated Input Power for the device is the same for AC and DC, then Amps used if I ran the energy from my battery through my inverter changing it from DC to AC, would be .54 Amps (Amps = Watts/Volts) 65W divided 120V = .54 Amps. And if the refrigerator compressor ran for one straight hour I would consume .54 Amp hours from my battery (not counting the roughly 10% energy loss from the Inverter process). If I ran the energy directly from my battery to the refrigerator and the watts or rated input power stays the same, I will be using 5.42 Amps (65W divided by 12 Volts). So I use about 10X the energy from my battery going DC instead of running it through an inverter to produce AC.
What am I doing wrong here? I’ve always heard, if possible, it is much more efficient to run a device directly from the battery (DC) instead of running it to an inverter that changes it to AC to run the device. My calculations above prove the opposite.
Assuming my calculations are incorrect, how does one figure out how many Amps a device will or can use under maximum draw for an AC setup versus a DC setup when the device is capable of doing it either way? Is the data provided below enough to make that calculation?
Input voltage (AC) 120 V
Input frequency 60 Hz
Rated input power (AC) 65 W
Input voltage (DC) 12/24 V
Thanks for helping this beginner.
Tim
