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77 points zdw | 3 comments | | HN request time: 0s | source
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throw0101c ◴[] No.46079266[source]
He mentions induction 'hot plates' towards the end, and says that they're limited to the same 1800W and 120V as kettles, but there are "commercial" portable induction stoves that are 220V and can go up to 3500 and 5000W; e.g.:

* https://www.vevor.ca/induction-cooktop-c_10592/vevor-portabl...

* https://www.trueinduction.com/Commercial-Single-Induction-Co...

Just need a NEMA 6 plug (GFCI/AFCI per code as well probably):

* https://en.wikipedia.org/wiki/NEMA_connector#Nomenclature

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maccard ◴[] No.46181012[source]
In the US. In the UK 2200W induction plates are readily available with a standard plug for ~£40, or if you spend a little more you can go to 3kW - [0] which is about the limit of most domestic circuits but is hotter than most gas hobs.

If you _really_ want more than that you can go a little mental and use one with an integrated battery which can push out 10 kW [1]

[0] https://www.nisbets.co.uk/nisbets-essentials-single-zone-ind...

[1] https://www.impulselabs.com/

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jchw ◴[] No.46181153[source]
This begs the question, and I've genuinely thought this before, of why we don't just strap a battery to a kettle and end this silly debate. If it takes 5 minutes to boil a cup of water in a 1000 watt kettle, that's somewhere around 80Wh... I guess it would be kind of expensive, but couldn't you make a pretty fast kettle with some number of high discharge battery cells?

(Well honestly, I guess the real answer is outside of Internet debates most people probably just don't consider 5 minutes to boil a cup of water to be a problem.)

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Nextgrid ◴[] No.46181169[source]
It would turn an inert device that costs a couple bucks to manufacture and has affectively no usage limit into a bomb that costs a couple hundred bucks (due to lack of economy of scale) and is limited by the battery's rated number of cycles. The battery's proximity to the heat source wouldn't help.
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jchw ◴[] No.46181621[source]
If people are willing to rewire their homes for kettles, I guess a couple hundred bucks isn't that bad.

> limited by the battery's rated number of cycles

Obviously the battery should be replaceable. (It should be in most electronics, really...)

> The battery's proximity to the heat source wouldn't help.

That doesn't seem like a particularly tricky problem to me. The standard kettle already tries as hard as possible to insulate the heat. If you were really worried it'd be possible to put the battery on a separate power brick instead probably.

...

And I guess I could've solved my own problem by googling it. There are tons of battery kettles on the market, including a 1500W one by Cuisinart and a 2200W (apparently?) unit by Makita. The latter is predictably expensive but the Cuisinart is available for around $100 where I live, which is definitely pricey but seems plausible.

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maccard ◴[] No.46182991[source]
> Obviously the battery should be replaceable. (It should be in most electronics, really...)

This is super wasteful when we can just hook up a heating element to an insulated tank and keep it hot like Quooker [0] does. Assuming the 3L tank, that would mean probably 20 minutes to heat the tank if it's entirely emptied for the US, but that's how long it would take to boil that water with an electric kettle _anyway_. If you want 5l of water for cooking, you cna use your 3L tank and fill it up with the "slightly lukewarm water that keeps coming through the tap", and then put it on the hob _anyway_. In the best case you're boiling 2L of water instead of 5 anyway.

> That doesn't seem like a particularly tricky problem to me. The standard kettle already tries as hard as possible to insulate the heat. If you were really worried it'd be possible to put the battery on a separate power brick instead probably.

Dunno what kettle you're using but no kettle I've ever used has been insulated. They're either plastic, or stainless steel. They do usually have a lid, which helps.

[0] https://www.quooker.co.uk/tanks

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1. jchw ◴[] No.46183245[source]
It doesn't have to be insulated like an insulated water bottle or anything, plastic is good enough for this. I have a cheap 120V kettle, nothing special, probably mostly plastic but with some superficial bits of stainless steel. After bringing a cup of water to a boil you can safely touch the base and anywhere on the kettle itself; there's not even an obvious sign of warmth anywhere except for the lid. If you don't believe me, I do have a thermal camera, but I assume this can be reproduced with most kettles, since it's not like mine is anything special.

Also: a hot water tank is just another type of battery. If it's really well insulated, it might work pretty good, but the self-discharge rate is probably still a lot higher than a lithium ion battery. If you aren't using boiling water every day this seems like it would be very wasteful.

I don't see anything terribly wasteful about the concept of putting batteries in a few more things. They're very recyclable, and already extremely abundant. It's not necessary, but neither is pushing several kW through a kettle just to get water to boil a bit faster. So really, that might be worth interrogating first...

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2. maccard ◴[] No.46191565[source]
> It doesn't have to be insulated like an insulated water bottle or anything, plastic is good enough for this.

Yeah I agree, but I was responding to the point of: > The standard kettle already tries as hard as possible to insulate the heat

Which isn't true at all. They make a token effort.

> Also: a hot water tank is just another type of battery.

You're technically correct, the worst kind of correct.

> don't see anything terribly wasteful about the concept of putting batteries in a few more things. They're very recyclable, and already extremely abundant. It's not necessary, but neither is pushing several kW through a kettle just to get water to boil a bit faster. So really, that might be worth interrogating first...

It takes ~320 kJ of energy to bring a litre of water from room temp to boiling, no matter what way you spin it. The difference between pushing 1500w or 3kW into the hot plate is "how quickly do you get to boiling", and has basically no bearing on the total amount of energy used to boil the water. Running a 1500w kettle for twice as long will use the same amount of energy, from the same source.

Using consumable li-ion/alkaline batteries to supplement that energy is _terribly_ wasteful - we've been through the "reduce reuse recycle" loop already with waste, lets not do the same thing with rare earth metals to avoid running a single cable to household appliances.

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3. jchw ◴[] No.46194913[source]
> Which isn't true at all. They make a token effort.

Look, the point was whether or not it would be okay to put batteries on it, not whether it would keep a drink warm for 12 hours. If the base is cool to the touch, I think it will be completely fine for batteries to be near it. If anything, making sure they're safe from shorting is probably a bigger concern.

> You're technically correct, the worst kind of correct.

The point wasn't to be technically correct, it's to point out that you can compare the properties of the two types of batteries like-for-like and realize that for many people interested in a faster kettle the boiling water tank idea might not be great. In America most homes have a water heater and it has to contend with the same sort of problem, only we use hot water multiple times a day every day (and at least in the Midwest, use LNG for heating it a lot of the time, which makes it economical if not particularly environmentally friendly.)

> It takes ~320 kJ of energy to bring a litre of water from room temp to boiling, no matter what way you spin it. The difference between pushing 1500w or 3kW into the hot plate is "how quickly do you get to boiling", and has basically no bearing on the total amount of energy used to boil the water. Running a 1500w kettle for twice as long will use the same amount of energy, from the same source.

Well duh. My very first post in this thread is estimating how much energy is required for a typical kettle to bring a U.S. cup of water to a boil. (Though obviously in reality you have to account for losses.)

My point here is that (a relatively small niche of) people are already doing crazy things like rewiring their houses (in America) to push pretty absurd power into kettles just boil water slightly faster, a time save that literally only even matters if you sit there and wait idly while the water heats up. The problem I have isn't that higher wattage kettles are somehow bad, it's that all of this time, effort and money for a time save measured in minutes is crazy. And it's the same for strapping batteries to a kettle or for keeping a water tank of boiling water too. I wouldn't bother with any of them, and don't. (But, as I opened this thread with, seeing how crazy people get over this, I do remain surprised at the relatively few battery kettles on the market.)

> Using consumable li-ion/alkaline batteries to supplement that energy is _terribly_ wasteful - we've been through the "reduce reuse recycle" loop already with waste, lets not do the same thing with rare earth metals to avoid running a single cable to household appliances.

I just counted and the room I'm currently standing in has 8 separate high capacity lithium ion batteries. We put batteries in our power tools, laptops, vacuum cleaners, tooth brushes, game controllers, wireless computer peripherals, air compressors, UPS units, the phone someone is currently reading this comment on, air dusters, garden lighting and certainly much more. Almost everything with electronics in it has batteries for something (if you inlcude smaller ones like clock batteries), and more often than ever, high capacity ones no less.

A battery operated kettle will forever be an expensive niche product, and it wouldn't even use that much battery in the first place. The environmental impact of all of those batteries would struggle to get to the level of 100 electric vehicles, and yet we are selling over 10 million of those per year.

Of all of the contrived and silly arguments, this is by far the most contrived and silliest of all of them.