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He looks shocked.
Mehby
Safety is no 1 priority!
Looking passed the absolutely insane answer here, no one has even brought up the whole issue of AC vs DC. Batteries are DC, while your fridge that plugs into your wall running on AC. I know they make DC ones, but it isn’t like they are interchangeable.
Funny thing, most modern refrigerators use DC motors for their compressors so that they can run at variable speeds, so there’s likely an inverter that you could bypass if you know the appropriate voltage. The DC ones for RVs are the same internals, just without the inverter.
Correction: they still use AC motors, but those motors don’t use line AC. It goes line AC > rectifier > DC > inverter board > variable frequency AC to run the compressor motor.
Most RV fridges just use DC motors, but there are some that use VFDs and AC motors.
Have we moved to BLDCs yet?
Funny thing, most modern refrigerators use DC motors for their compressors so that they can run at variable speeds
No they don’t…they use AC motors and a VFD to control the speed.
I mean it’s probably labeled, right? How hard could it be?
Exactly. Find a hole that’s black and a hole that’s red, and stick some wires in there. How hard could it be?
(can’t answer, because she was fucking electrocuted)
Shannon Martin says just shake the battery and you’ll get AC.
Just swap the leads back and forth very fast
Just run the rectifier in reverse, duh
There are DC-AC converters you can use (might be called inverters in English idk), which are pretty interesting circuits. They are used all the time, e.g. to use solar energy
That part just takes an inverter.
I’m not sure of the max load output on a car battery, but with a 15 amp 1800 watt dc to ac inverter, you probably can run a fridge off one. It probably just won’t last all that long.
Hello, expert solarpunk here.
TLDR: Car battery is 350Wh. Fridge uses 143W idle, so it’ll run a fridge for 2-3 hours.
Explanation below:
Car batteries are lead-acid (sulphuric acid and lead plates).
They discharge according to Peukert’s Law as the negatively charged plate gets covered in lead via the acid (electrolyte).
As the battery depletes, the negative plate can begin to take permanent damage, and so you can’t discharge a lead-acid deeper than 10-20%, or about 10.8V, with the safe limit being ~50% discharge.
Most 12V, 60Ah batteries therefore only safely store and nominally discharge 350 Wh @ 350W.
You can discharge that as fast as you want but the faster you discharge, the lower the capacity is (with 1000-1500W bringing you way down to like 65 Wh). Fridges have a surge when they start up to fire up the compressor. Starter batteries can take that, but once the refrigerant is cold, the fridge just maintains the temperature which uses a lot less energy - about 143W on average.
Fridge uses 143W idle
Isn’t that like 1250 kWh on an annual basis of idle usage? An efficient fridge should use 150-200 kWh per year, this isn’t just idle usage. Even an inefficient fridge would be really high with that kind of idle usage.
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Watt hours are watt hours. Sure the compressor won’t run on 12 volts as is but the energy is there, just needs a converter.
Fwiw, our 15 year old fridge uses around 1000Wh per day.
That’s a big joule thief
Sure, buy an inverter and burn up 10% of your energy in the conversion if you’re lucky. That inverter will cost roughly as much as the contents of a standard fridge + freezer, by the way :)
At that point just buy a well insulated cooler and always have some ice on hand. It’ll last much longer.
The question wasn’t “Is it efficient or cheap”, it was how much energy is in a battery, and if and for how long would it run a fridge. If you also want to add one more point to why you probably shouldn’t do it, car starter batteries don’t generally like to be deeply discharged, you’d want to get a marine battery for that use.
As for how much the inverter would cost, depends on the fridge, but Amazon has a 1000W inverter for around $85, that should be enough for most. Ours could run from a 300W one, they cost around $30. Pretty handy devices if you want to run any kinds of electronics from a car anyway, I have one for when I want to charge my laptop and RC batteries on the field.3500 watt inverter is 300 dollars at a Flying J. Mines 7 years old and was used 5 years straight when I was a trucker, as I removed the 12v factory fridge that could kill 4 batteries over night, with a 110v fridge, I could safely leave food in all my days off and the truck would still start. Now it’s hardwired to my pickup as a emergency generator and electric impact wrench power source. People laugh initially when they me pull out the impact and then ask what it cost. I also mounted a coffee maker behind the seat because gas station coffee is fucking garbage and its 4 hours to a major center
Energy is energy, you are not an electrical engineer.
Congratulations, this is the worst attempt at ridicule I’ve ever seen
Your comment was ambiguous, stupid, and designed to ridicule. If you are attempting to imply inverter and other loss then be more specific. Regardless, the comment you were referring to already provides arbitrary values that you can assume include loss.
So please explain to me what the fridge being 12v DC or mains AC powered has to do with anything, when an example uses arbitrary power and energy values? I’m genuinely curious.
ooh getting aggressive now are we?
I owe nothing to you. Enjoy your time being a sad person trying to bring others down on the internet :) I hope this little outlet makes you feel better
Ad hominem dodging of the question. Classic.
No answer? Ok, you’re just sad that your comment was dumb lmao jeepers
No it doesn’t. Watts do give a shit what percentage is voltage vs amps. You have to convert between AC and DC as appropriate as well as ensuring the voltage of a 12v battery is stepped if needed, but the watts are the same in any case. (Not figuring for system losses)
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You should Google what a step up and step down transformer do. It’s very simple and easy to prove you’re a dipshit once you understand you’re arguing from bad faith trying to compare a simple bit of circuitry design to hydro power.
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https://youtu.be/GtTcuexjeRw?si=e1p0nUHh1uXBp24R
3 seconds of googling like I said
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I don’t know… you didn’t mention your uncle once…
That’s because he is his uncle. You’re seeing the source material, be amazed
Does… Does he work at PlayStation?
It’s a secret. You’ll have to ask his uncle
Wow, those are some serious Licensed Insurance Agent skills
Fridge uses 143W idle
The only thing running in idle is the timer and power led, which consume insignificant amounts of power. By my calculations, the average modern fridge does bursts of ~300W during compression and defrosting cycles, with ~40-50W consumption on average over long periods.
You have a very inefficient fridge! My fridge is rated for 272 kWh per annum, which is 745 Wh per day or 24 Wh per hour. You need to buy a new fridge.
You did not answer their question. They asked for Watts, not Watt hours. Average car batteries have a CCA in the range of 500 to 1000 Amps at 12V, so you could reasonably have 12kW in there :D
This reads just like an AI response
AI told me 75C/170F is ideal for hot tub water temperature.
Sure no problem. Once I get used to that I’ll work my way up to boiling peanut oil.
If nothing else, the tub would certainly be hot at that temperature.
It is at this point that the reader questions their own existence.
In the tub. For a relatively short time.
Reading
At what temperature does it cease to be a bath and instead become human soup?
75°C is definitely ok for a hot tube for a short session.
