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He looks shocked.
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.
At what temperature does it cease to be a bath and instead become human soup?
It is at this point that the reader questions their own existence.
In the tub. For a relatively short time.
75°C is definitely ok for a hot tube for a short session.
Forget 75°, just 65°C (150°F) will give you third degree burns in 2 seconds:
Most adults will suffer third-degree burns if exposed to 150 degree water for two seconds. Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns.
(°F)
(Third °F burns)
To be honest three degrees burn doesn’t sound bad. I’m looking at my protractor and as long as you aren’t far away from the tub three degrees shouldn’t burn that much
Most adults? What happens to the others?
They will instantly explode into pure energy
I guess I’m long dead, lol.
Just brain dead 😅
Temperatures beyond 50°C are an acute risk. 75°C can cause lasting damages.
Yeah but you are talking about hot tubs and they are talking about hot tubes so maybe the rules are different like the tube is really hot but is a poor thermal conductor. Or they misspelled tub and they really like burning themselves… lots of options for interpretation here.
Ever been to sauna? Especially the Russian one? There’s no risk if you don’t have heart issues.
I’m regularly going to a Finnish sauna with >80°C, but air with 100% humidity is not the same as immersing yourself in scalding hot water.
The Finnish sauna is dry. Russian and Turkish are wet with high humidity.
Sure but you can only do it once!
Seriously, even 75C water coming out of the tap would be dangerous and negligent.
It’s usually 96 if you have a boiler. No issues.
But only if you have purple eyes
I spilled a half cup of 175F water on my hand and got blisters. You absolutely cannot bathe in it.
I meant to reply to the parent comment
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.
Shannon Martin says just shake the battery and you’ll get AC.
Just swap the leads back and forth very fast
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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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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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.
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.
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.
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.
classic example of being wrong with authority.
We know this comment by Shannon Martin is correct and sensible because it was reviewed by Shannon Martin! As a licensed insurance agent, I’m sure she is qualified to talk about uh… electronics… hmm
That answer is like the electronics version of the image with Patrick Stewart and the caption:
“Use the force, Harry
-Gandalf”
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I run a fridge freezer off a Delta Pro and 600w of solar during the summer. If we get a few days spell of bad weather I have to place it back on mains. Its good to have in an emergency, though it cost me 3 months wages (plus overtime)
An inverter will not let you run your fridge until the battery is “dead”. It’s going to have a low voltage cut off, likely somewhere around 11 Volts, specifically to avoid damaging batteries by fully discharging them.
How many hours you’ll get from the battery mostly depends on your ambient air temperature and how often you open the fridge. They don’t use that much power when they’re idle - my fridge averages at about 90 watts (I’m not running off grid, but I do have rooftop solar and our system produces pretty charts showing consumption). A large car battery can sustain 90 watts for a quite long time - well over 2 hours. Probably closer to 10.
Running a fridge off a car battery long term is a bad idea. But in an emergency? Sure I’d totally do that - especially if your “emergency” is genuine such as needing to keep your medication cold. Just don’t open the fridge unless you’re taking your medication.
LifePo4 FTW!
Sure. Way better than lead acid. But that doesn’t mean lead acid is useless. When I lived off grid, LifePo4 didn’t exist and we got close ten years (of daily use) out of our lead acid batteries. They were bigger than car batteries and also deep cycle ones, but in an emergency a car battery would be a fine choice if it’s the best one you have.
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Wait, so you are saying you have either lived continuously on a 29ft boat for 5 years, or only have visited land by dinghy or something while its anchored?
Wild. That’s got to be a nasty looking hull though.
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Accept the battery is DC 🔋and fridge runs on AC🔌
At least with the 12v to 120v it just won’t work instead of exploding
And it turns out to be an ac motor in the compressor causing the fridge and the battery to short out If it stalls on a coil. The ac motor burns up with the battery. The electronic, water dispenser, and the ice maker would probably be happy assuming it’s a full bridge rectifier otherwise polarity would matter but most likely wouldn’t break it.
I’m not an engineer just a guess.
