comitan
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AMPS-WATTS
I want to run a 2amp draw refrigerator off an inverter, can someone tell me the draw in 12V watts? What size inverter.
Strive For The Ideal, But Deal With What\'s Real.
Every day is a new day, better than the day before.(from some song)
Lord, Keep your arm around my shoulder and your hand over my mouth.
“The sincere pursuit of truth requires you to entertain the possibility that everything you believe to be true may in fact be false”
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ncampion
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Volts X Amps = Watts
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BajaBruno
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If I remember this correctly, watts are watts at whatever voltage, so, if your amps are rated at 120vAC, then it would draw 240 watts at any voltage
(Volts X Amps = Watts , as ncampion writes).
Christopher Bruno, Elk Grove, CA.
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BigWooo
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| Quote: | Originally posted by comitan
I want to run a 2amp draw refrigerator off an inverter, can someone tell me the draw in 12V watts? What size inverter. |
If you're trying to find out if the inverter is big enough, you should make sure your inverter can handle at least a 25 to 50% surge capacity above
the 240 watts that the refrigerator will draw. When the fridge motor turns on, there is a brief power draw above the 240 watts.
If you are trying to figure out if your batteries will run the fridge for X amount of time you need to monitor the fridge and see just how many hours
it's actually running per day. It doesn't draw 240 watts X 24 hours.
A Kill-O-Watt device works great for that.
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Paulclark
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2 amps at 110 volts equals 220 watts. 220 watts at 12 volts equals 18.3 amps. You will draw 18.3 amps at 12 volts.
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comitan
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Thanks all, I think you covered nicely even I can understand, The inverter I have is 800Watts with 2 golfcart batteries should handle for overnight.
Where I was confused is watts AC-DC but they are the same.
Strive For The Ideal, But Deal With What\'s Real.
Every day is a new day, better than the day before.(from some song)
Lord, Keep your arm around my shoulder and your hand over my mouth.
“The sincere pursuit of truth requires you to entertain the possibility that everything you believe to be true may in fact be false”
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BajaWarrior
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| Quote: | Originally posted by comitan
Thanks all, I think you covered nicely even I can understand, The inverter I have is 800Watts with 2 golfcart batteries should handle for overnight.
Where I was confused is watts AC-DC but they are the same. |
Two batteries sounds a little light for overnight. The inverter will go into low volt alarm by midnight. Turn off the fridge overnight, wait for the
sun to come up and hit your panels and re charge the batteries for the day.
Haven't had a bad trip yet....
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comitan
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Ok lets take this farther, the batteries are 6v rated 220Amp hour at 20hr rating, will 2 of these in series give 440Amp Hr or still 220 AH. If using
the 220AH rating
I figure 20amp per including loss I would only have 6 Hrs.?????
Strive For The Ideal, But Deal With What\'s Real.
Every day is a new day, better than the day before.(from some song)
Lord, Keep your arm around my shoulder and your hand over my mouth.
“The sincere pursuit of truth requires you to entertain the possibility that everything you believe to be true may in fact be false”
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BajaWarrior
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| Quote: | Originally posted by comitan
Ok lets take this farther, the batteries are 6v rated 220Amp hour at 20hr rating, will 2 of these in series give 440Amp Hr or still 220 AH. If using
the 220AH rating
I figure 20amp per including loss I would only have 6 Hrs.????? |
That is if the batteries are in excellent condition...
Haven't had a bad trip yet....
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BigWooo
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| Quote: | Originally posted by comitan
Ok lets take this farther, the batteries are 6v rated 220Amp hour at 20hr rating, will 2 of these in series give 440Amp Hr or still 220 AH. If using
the 220AH rating
I figure 20amp per including loss I would only have 6 Hrs.????? |
If your batteries are fairly new, using real life figures including battery inefficiency and inverter loss, with your batteries in series, at 12 volts
you should be at almost 50% battery capacity in 5 hours of continuous use of your fridge motor/compressor. You don't want to discharge past 50% or
your batteries will suffer damage (if done repeatedly)
Now remember, your motor shouldn't be on continuously so your fridge will stay cold much longer than that.
This isn't real accurate, but it's a good ballpark guide:
>12.6 volts = fully charged
12.3 volts = about 75% charged
12.0 volts = about 50%
11.7 volts = about 25%
Under 11.4 volts totally discharged
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Al G
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Wiley...how many amps solar are you pumping in?
Albert G
Remember, if you haven\'t got a smile on your face and laughter in your heart, then you are just a sour old fart!....
The most precious thing we have is life, yet it has absolutely no trade-in value.
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CortezBlue
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Sounds to me like someone is worried that there beer will stay nice and cold!!
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Bob and Susan
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actually we really DO need more info...
battery cable size in important
kind of inverter
how are you charging the batteries
heat in the day and night affects power
size of wire from charge source
controler (cheap ones waste 30% of the power)
surge is nothing
lengh of time the fridg is working at night
how old are the batteries
remember the battery charge has very little to do with the voltage
you need to check with a hydrometer
but there is a little coralation to voltage
amp hours from the battery companies is just a compareison number
it isn't really a true number
12.6 is a min full charge
i would say 13.5 would be a
better FULL charge for your batteries in daily use
you need to tweek the settings to get performance
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Bob and Susan
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oh yea...
i think with 2 6v bateries and a 200w fridge working you'll be "dead" in 3 hours and the cheap 800w inverter will be "screaming"
but...i could be wrong
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BigWooo
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| Quote: | Originally posted by Bob and Susan
oh yea...
i think with 2 6v bateries and a 200w fridge working you'll be "dead" in 3 hours and the cheap 800w inverter will be "screaming"
but...i could be wrong |
Bob's right. I didn't think about you're using an off the shelf inverter that probably draws a huge amount of additional power.
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comitan
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Ok got the message, $200 will by a lot of ice.
Strive For The Ideal, But Deal With What\'s Real.
Every day is a new day, better than the day before.(from some song)
Lord, Keep your arm around my shoulder and your hand over my mouth.
“The sincere pursuit of truth requires you to entertain the possibility that everything you believe to be true may in fact be false”
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Bajajorge
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Buy a propane fridge. 
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BigWooo
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| Quote: | Originally posted by Bajajorge
Buy a propane fridge. |
There's a used one for sale in the Baja Western Onion for $800
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Bob and Susan
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propane fridges really dont work all that well in the summer
electric is way better
but remember...
you'll get to turn it up-side-down once and a while too
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