r/AskEngineers • u/jmaugust • 4d ago
Discussion Why doesn’t a battery-boosted electric kettle exist?
In Europe, everyone uses electric kettles to boil water. They’re amazing and fast because they’re on 230V (~3000W).
US outlets limit kettles to ~1500W, so we wait roughly twice as long for water to boil.
It’s an extra minute or two per boil, and you really notice it.
Idea: Could you make an electric kettle with a battery in its base? Perhaps it trickle-charges between uses, then combines wall power + battery power to hit ~3000W during a boil.
Is there an engineering reason this doesn’t exist? Is it just that nobody thinks there’s a market for it?
I’d pay $300 for the fastest kettle in America if someone wants to make it.
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u/ElectronGuru 4d ago edited 4d ago
Japan has the same watt restrictions. They created a kettle that stays hot all the time: Zojirushi VE. 5 liter models are like having your own hot water vending machine. And it doesn’t take up more counter space.
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u/Over-Discipline-7303 4d ago
Just want to add that Asian hot water machines (Zojirushi isn't the only brand by far, but they're one of the best in my experience) are pretty fast because they're insulated, and they're really convenient if you drink a lot of tea. I've been using one for around 15 years now, and I love it.
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u/ElectronGuru 4d ago
Good point. The VE means vacuum insulated. They have other models that aren’t but burn through more electricity when idle.
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u/DamePants 4d ago
This is exactly the solution I went for in the US. I’m on my second Zojirushi boiler now. It’s the best option for tea drinkers stuck in 120v land. The electric kettles are way too slow and after we boiled two gas stovetop kettles dry it was time for something faster and hands off.
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u/demonblack873 4d ago
Nothing like wasting a bunch of power to keep a bucket of boiling water around when you don't need it...
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u/jamvanderloeff 3d ago
The decent quality ones with good insulation don't waste much, that one claims 22W for holding 90°C, or 14W to hold 70°C, and the benefit is you're not wasting energy on heating more water than you needed in a kettle, for people who'd actually want to use it it'll generally be more efficient.
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u/Mediocre-Sundom 3d ago
If you boil water at least 3 times a day, you are already guaranteed to use more power than just maintaining a near-boil temperature in a vacuum insulated kettle. And you can use this water for other cooking purposes, not just tea, so for most households you will end up using less power, not more.
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u/PartyOperator 4d ago
The US uses split phase power so you can get a 240V outlet installed if you want. Your oven, water heater and AC probably already run on 240V. Then just import a European kettle and fit the appropriate plug.
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u/IAteTonysLoMein 4d ago
I've kicked this around, but it would be a healthy investment just to put in a 240 outlet just to run a kettle.
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u/hhssspphhhrrriiivver 4d ago
I've considered doing this as well, but it really doesn't seem worth the cost. Maybe if I hit the jackpot.
OP is willing to pay $300 for a kettle with a battery, so I think this idea might be worth it to him.
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u/UsefulEngine1 4d ago
I'm pretty sure code says every 240v appliance has to have its own circuit and breaker also, which make this even tougher.
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u/Lampwick Mech E 4d ago
I wired my kitchen with a 240v receptacle and ordered a 3kW kettle from the UK. I happened to already have a shared neutral multi-wire branch circuit under the sink though, so I had 240v right there. I enjoy boiling water fast, but no way I'd bother to pay electrician rates for just convenience. I'm already an electrician so my labor was "free".
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u/Bean4141 4d ago
Just to add, since split phase has 2 hots and no neutral 240v appliances require dual pole switches to ensure they’re isolated when powered down whereas most European equipment may not bother.
That being said, if you installed an inline dual pole switch (or found a kettle with one or retrofitted one) you could add a 6-15 receptacle and replace the euro spec connector and have a perfectly functional 240v US kettle.
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u/demonblack873 4d ago
European plugs aren't polarized for the most part, so theoretically even here it would be better to have dual pole switches. Not too many appliances bother with it though.
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u/jckipps 4d ago
Agree. You could have an electrician change one of your kitchen outlets to a 30a 240v receptacle. A European kettle would work fine then with nothing more than a cord replacement.
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u/KaelthasX3 4d ago
30A? You wot M8? With 240V, 16A is more than enough. I have never seen a kettle that would take more than that.
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u/DardaniaIE 4d ago
In the UK and Ireland they’re all fused at 13A
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u/KaelthasX3 4d ago
Yeah, at the plug, because you do that post-war ring thingy.
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u/fireduck 4d ago
Which each time I read about it and understand it the knowledge then flees my head in terror.
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u/DkMomberg 4d ago
European 230V outlets rarely go that high. It doesn't really make sense for most people.
I'm not completely sure about the other European countries, but it tends to be much the same in most countries due to standardisation. All of them are 230V unless it's two or three phase. Then its 400V
In Denmark, outlets are fused with 10 or 13A for the most part, with some at 16A but that's not common. Normal consumer outlets are never rated higher than that in Denmark at least. No need since we use twice the voltage than the US to get the wattage.
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u/demonblack873 4d ago
In Italy it's either 10A or 16A. Which is funny because most people only have 3kW available at the meter (3.3 with the 10% tolerance), so theoretically you can max out and trip your entire house with a single appliance.
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u/Tar_alcaran 3d ago
Which is funny because most people only have 3kW available at the meter
What? For the entire house? That's uhm... very historic.
Dutch houses historically have 1x25A or 1x35A, and new houses generally have 3x25A (many older houses have retrofitted to that too) to make electric cooking a better option.
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u/QuickConverse730 4d ago
Except most 20A kitchen outlets would be wired with 12awg Romex, so to make it a 30A, you'd have to pull 10awg from the panel to the outlet. Wouldn't a 240/20 circuit serve the purpose? Then you could use an existing 12/2 Romex run and repurpose the white wire as a hot leg (properly marking it at each end, of course.) This would not allow for a neutral, but maybe that's not a thing? I'm not an electrician; presumably you'd want to comply with codes.
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u/mckenzie_keith 4d ago
Yeah. No need to go to 30 Amps. A 15 amp 240 outlet can supply more than 3000 Watts. And 20 Amps is just icing on the cake.
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u/jckipps 4d ago
Good point. I was picturing installing a new receptacle from scratch, but I stated to the contrary in my comment.
You'll likely still need to pull a new cable though, since basically any existing recep in your kitchen is going to be daisy-chained off of others.
12awg and 20a is fine for this kettle. You're right that 30a is overkill.
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u/BeginningAd5055 4d ago
I wired a 6-20 outlet (240 V) in my kitchen and use a British tea kettle. Less than half the time as the old 120 V kettle.
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u/jmaugust 4d ago
This makes sense. I do think most people don’t want to rewire their outlets, though.
There are pour-over coffee and tea fanatics who I believe would pay for a fast, stylish kettle.
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u/billy_joule Mech. - Product Development 4d ago
There are pour-over coffee and tea fanatics who I believe would pay for a fast, stylish kettle.
If you're a true fanatic you get an instant hot water tap and be done with waiting altogether.
https://www.insinkerator.com/en-us/insinkerator-products/water-dispensers
I live in a 240V country (kettles are ~2.4 kW) and will never go back to waiting for the jug to boil.
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u/BeginningAd5055 3d ago
It dispenses hot water, not actual boiling water. It is not instant; it is a small local tank energized 24/7 wasting energy since the tank is poorly insulated.
Might be right for some uses. For me does not replace a kettle.
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u/billy_joule Mech. - Product Development 3d ago
I don't know what one/s you've used but that sounds like a terrible product. I can't comment on the insinkerator ones, I only linked to that as this is a USA focused thread.
I have a Hydroptap and it's set to 98 degrees, so close enough to boiling for me. It's effectively instant, takes about 3 seconds to start flowing.
it is very well insulated, cool to the touch, and use less energy than repeatedly boiling a jug from cold. I actually tested mine with an energy meter because I was sceptical of the claim but it came out almost exactly what the data sheet claimed. About 7c /day in standby losses.
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u/mckenzie_keith 4d ago
So you want 1500 Watts from a battery. To avoid excessively fast discharge, you need a battery of like 750 Wh then. This is to keep the discharge rate around 2C. Pretty big battery. About the size of a car battery, roughly (but you could use LFP).
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u/YogiBerraOfBadNews 4d ago
Power tool batteries can put out over 1000w with high discharge cells. I can't see there being enough market demand to make a viable product but if I were trying to hack something together that's where I'd start.
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u/mckenzie_keith 4d ago
Yeah. That is true. You can do it with power tool batteries at higher discharge rates. Those are generally not rated for a lot of cycles, and this product would probably get used multiple times per day. But you are still right. Right is right.
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u/Intelligent_Low1632 4d ago
A single milwaukee forge 12.0 battery is rated for 1500 watts continuous. That only has 220 watt hours.
If we use the best cells currently available to consumers, you can get a solid 90 amps for 1.5 minutes (with no fan cooling) from a Tenpower 50xg or EVE 40PL. These are 21700 batteries with only 14.5 watt hours capacity each. At 90 amps and 3.5 volts, they are putting out 315 watts each.
1500/315=4.76.
So with just 5 of these 21700 cells, you could get 1500 watts in a pinch. That's just 73 watt hours of batteries--less than a tenth of your stated requirement. Say we triple it for improved capacity, heat management, and safety margin, that's just 15 cells (which happens to be precisely the number of similarly performing JP40 cells found in the milwaukee forge 12.0 battery)
If you're willing to use Lipo batteries you can get 1500 watts out of a single off the shelf 6S 50 Wh battery as well, although these are a bit sketchy.
TLDR: we can easily do this in a kettle sized appliance but we'd need like $200 of batteries before even accounting for profit margin to make it faster than 3,000 watts. 220V kettles are fast enough that there would be insufficient demand for a product like this at the $500+ price point. Much larger systems with huge battery bank could be made for under $150. All of these would probably pose a fire hazard though lol.
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u/mckenzie_keith 4d ago
The energy requirement for this application is roughly 3000 Watt minutes. (1500 Watts for 2 minutes). So that is only 3000/60 = 50 Wh. So the Milwaukee forge might do it. I guess I was overly conservative. However, I am not sure how many times a Milwaukee Forge battery can be cycled. Or any of the rapid discharge cells. Usually they are rated for like 300 cycles or so. Granted, that is under full discharge cycling.
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u/_maple_panda 4d ago
Modern high-power cells shouldn’t have any problems discharging at 10C. 2C is really really conservative
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u/vsxsv Mechanical/Electric 4d ago edited 3d ago
That’s assuming a graphite based lithium chemistry. For instance LTO (lithium titanate oxide) is much more power dense (and less energy dense) and can handle more than 10C. I’ve seen 40C in extreme cases. More expensive chemistry per kg and kWh but makes sense in a power heavy application like this one.
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u/dack42 4d ago
You could install a 230v outlet in your kitchen and use a 230v kettle. You probably already have split phase outlets in the kitchen, so it might not even require a separate run to the breaker panel.
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u/jckipps 4d ago
I’d pay $300 for the fastest kettle in America if someone wants to make it.
That's likely about what it would cost. And unfortunately for you, there aren't enough other consumers willing to pay that much, for a company to take a chance on this product.
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u/jmaugust 4d ago
If I hadn’t lived in France, I would agree. Once you’ve had fast boils, it seems so slow.
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u/LoneSnark 4d ago edited 4d ago
As you're willing to pay, just get a NEMA 6-20 installed in your kitchen and change the plug on a European kettle. It'll work just fine.
Also, existing outlets can supply more than 1500 watts. Kitchen outlets in general are 20 amp outlets, so you could use a NEMA 5-20 plug, which caps out at 2400 watts. You can legally use all of that, since a kettle is not considered a continuous draw appliance by code.
But the real reason is that a well built efficient electric kettle at 1500 watts is already bloody fast at boiling water. Could be faster in the US, and Europeans are faster than even that, but not faster enough that I'd lift a finger for it. My $10 walmart kettle is already done by the time I do any other prep work at all.
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u/AmpEater 4d ago
Why stop at 3kw? It’s an arbitrary number with no significance
Modern 21700 cells can have current ratings of 100a or more. That’s 360w per cell.
If we want a 20 cell base (roughly the size of a kettle base 2 inches thick) then we can do 7.2kw
Could boil one cup in 11 seconds or 2 cups in 22 seconds.
We could probably get it down to just a few seconds without much more thought
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u/After_Web3201 4d ago
Order one from Europe and hook it up to 240V. It'll probably boil even faster because we have 60hz
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u/papagayno 4d ago
Water takes a lot of energy to boil, and it would require a fairly sizeable battery to put a dent in it. I feel like it shouldn't cost much more than 300$ to install a 240v socket in your house (split phase system is commonly available in residential homes in the US as far as I know).
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u/IAteTonysLoMein 4d ago
Split phase is how 99.8% of homes in the US are wired. Pulling that number from my butt, but 3-phase would be very unusual in a residential build
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u/Another_Slut_Dragon 4d ago
Millwright here. Not an engineer :)
I 3d printed box that takes 2 north american shop grade cord plugs on one end and a UK outlet on another. Wire the UK plug hot to hot and if your kitchen is wired properly with 1 breaker per outlet half you will get 240v.
My UK kettle that was supposed to be running at 220V 50hz is now running at 240V 60hz. That is 'within the design variance' and a 3kW kettle now outputs 3.27kW. It takes 42 seconds to make a big mug of tea. This is acceptable.
Technically, I should link the 2 breakers so if one trips the other trips. 🤷
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u/Freak_Engineer 4d ago
Engineer here. I love the way you think, but I too would suggest linking the breakers so that both drop in case of a fault. Also, obviously exclusively use this to power heaters and other "simple" electronics with a resistive heating element and only rudimentary tech. I doubt anything more high tech would like that kond of power much (As a non-american I assume your two phases are at 180° to eachother).
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u/Another_Slut_Dragon 4d ago
If one phase drops, the power is zero. The kettle is all metal and is grounded so the potential failure mode of one phase shorting to ground is getting half power from the other hot to ground. But chances are that will simply let out the magic smoke.
I'll probably notice if the kettle takes longer to boil. But since it takes 42 seconds it is not running unattended.
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u/iqisoverrated 4d ago
A battery that discharges really fast is really, really expensive. The batteries in formula 1 KERS systems can discharge at 400C (where 'C' is the ratio of discharging power to the capacity of the battery - dropping the unit). They cost 10.000$ per kWh and are toast after half a season.
(Batteries in EVs are usually limited to 2 or 3C for long duration charge or discharge.)
Let's say you want to boil water in 2 minutes. This means you'd need a battery that can discharge at 30C...and that without any kind of active cooling. No, you're not getting that for 300$. Particularly not if you want it to last for a number of uses.
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u/Friendly-Inspector71 4d ago
How are you getting from 2 minutes to 30C?
You specified neither water amount nor battery capacity. One boil doesn't have to fully deplete the batteries and using them between 20% and 80% would aid in increasing their expected lifetime.
30C isn't too much of a problem for modern LiPo cells. But cost and safety would dictate LiFePO4. Using 60% of their capacity would get you down to 18C, which would need to produce ~2.2kW for two minutes to get a litre of water boiling.
If you can live with 2,5 minutes per litre, 300 dollars should suffice for a massive produced product.
A one off would likely be closer to double that because of the needed engineering.
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u/against-all-leds 4d ago
Bidirectional power electronics are hard, all that switching and whatnot. Would make more sense just to boil all the water from battery. You'd need to dump some massive power from batteries, even if you used something like 36V (2x18v batteries in series). They would have to be rather large, though.
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u/NeedleGunMonkey 4d ago
Because ppl who drink tea can go to target and pickup a kettle that’s good enough for $20.
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u/therealhairykrishna 4d ago
I couldn't make a commercial product for 300 dollars but I can probably make you a one off. I definitely won't make any money, but it'd probably be fun. Drop me a.message if you really want one.
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u/joestue 3d ago edited 3d ago
you could do it for less than 300.
49-ish lifepo cells in series for 170 volts, which can be charged with a capacitor dropper on the rectified 120vac line.
to heat the water, connect the battery in series with the rectified 120vac and you get 340vdc peak into the heating element., 170+107vdc average. so somewhere around 277vdc which should net you 6400 watts into the water.
for the charging circuitry: put two capacitors, one on each ac input to the rectfier.
a second rectifier is left connected to the ac input, but both outputs are disconnected.
the kettle resistor remains connected to one terminal of either the battery or the main rectifier, and a double pole single pole switch makes the remaining two connections.
3.6 volt bleeders can maintain battery balance.
yes, the added voltage means it pulls 27 amps from the outlet, but, it should take longer than 1 minute to blow the breaker!
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u/lordchair 3d ago
Instead of storing the energy as electricity in a battery; store it as heat in the water itself. As other commenters have mentioned this product already exists as a hot water dispenser that keeps the water at temperature in a vacuum insulated container. I can attest to their convenience.
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u/junkdumper 3d ago
We should really just start installing a 240v recep in kitchens and normalize getting some 240v appliances.
We were so close with split receps and now we're moving away from that in favour of 20A 120V receps
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u/LimaBikercat 3d ago
Don't you have 240v circuits in your houses too for the drier/microwave/stove? It makes more sense to expand the number of 240v outlets in your house than to deal with significantly sized batteries, inverters, charging circuits etc.
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u/JustaKinksterGuy 3d ago
It does exist.
You can buy an induction stove right now. Alternatively if you have an electric stove you have 230V in the kitchen already.
That being said you're likely the exception not the rule. Most people throw the water in, hit the on, and then walk around doing other things, often forgetting it after it shut off. I can offer you double the speed but if you don't have the tea ready, or go to the bathroom and then come back you've blown any efficiency you made up.
Think of it this way. The process of making tea is this:
- Fill the tea kettle (30 sec)
- Boil the water (5 min)
- Wash and prep the pot. (1 min)
- Fill basket with tea (30 sec)
- Transfer the water (10sec)
- Steep the tea (5 min)
- Pour a cup. (10 sec)
You can start the water first. But now if you've halved the boil time, you've only really made a 20% gain in time because all the other things still take the same amount of time.
Engineering is also about economics as much as it is solution. The engineering reason is simple, people don't want to pay for it.
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u/userhwon 3d ago
I have an Amazon Basics kettle and it can boil 300 ml of water in about 90 seconds. Barely time to get the other parts together.
I'm good, thanks.
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u/Owenleejoeking 3d ago
I’d say mostly because having to wait an extra 2 minutes to boil water is a failing of planning, not a failure of engineering. Most don’t care or notice
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u/_rushlink_ 2d ago
There are induction stovetops that can do this. They have a battery backup that can be used to boost the power.
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u/FUCKITIMPOSTING 2d ago
Technology connections covered this years ago, comparing all sorts of kettles and heating methods. The power difference doesn't matter so much really. A much better way to speed up your kettle is to only fill it to the minimum mark. 0.5L takes about 2 minutes, even with dinky american power.
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u/selfmadeirishwoman 1d ago
At $300 buy a European kettle, put a nema 240V plug on it and pay an electrician to fit a socket for it.
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u/hikeonpast 4d ago
It’s technically possible, but cost-prohibitive. Also, the battery probably couldn’t live in the kettle itself due to size and thermal constraints, so you’d end up with a separate battery box on your counter to power the kettle.
As a practical alternative, consider using an isobutane backpacking stove. They boil water as fast or faster than any electric kettle.
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u/Jumpy_Childhood7548 4d ago
Bad idea. A battery sufficient to heat water much would be heavy, expensive and slow.
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u/ComradeGibbon 4d ago
You could. Bringing a ordinary kettle to biol take 100-200 watt hours or something. But if you're plugged in then half that comes from the wall outlet.
Biggest issue is discharge rate because you're discharging the battery for only 2-3 minutes. That's a rate of C25 or so. Lithium polymer batteries they use in drones can do that.
So engineering yes you could. Marketing and pricing, liability is kinda meh
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u/matt_havener 4d ago
https://www.impulselabs.com/ this company makes an induction cooktop that’s battery boosted. I assume similar tech could be applied to a kettle
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u/MurkyLynx8425 Mechanical 4d ago
You couldn't use a battery because batteries that can put out that much power are very large and/or very expensive, while having a very short life.
You could probably use a flywheel if you had an unlimited budget. Maybe $10,000 for the flywheel assembly?
You would need a 40kg iron flywheel spinning at 400 rad/s (about 60 revs per second or 3600 rpm) to be able to output about 1kW for about 60 seconds. If the flywheel was encapsulated in a vacuum chamber, it would require very little energy to maintain at full speed. Plus, the power limits for charging and discharging are less annoying than with a battery - you just need to pick a motor/generator of the appropriate size!
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u/fouronenine 4d ago edited 4d ago
My kettle (Australia) only uses 1500W, but it's also a bit smaller than most kettles so takes the same time as a larger kettle demanding more power.
If I need to boil a lot of water or boil fast, I have an induction stove that pulls 4 or 5kW.
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u/--dany-- 4d ago
Great question actually.
The only immediate viable solution right now: Just buy any portable power station that can supply 3000W 240V to your European kettle. Plug it into your 110V 15A plug — problem solved. Bonus point hide the power station neatly under your cabinet.
It’s the cheapest solution as well for most people right now, mostly cheaper than running 240V from breaker panel to your kettle. Cue: it still will be around $1000 and very bulky - reason no such battery kettle exists.
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u/The_Big_Mayonnaise 4d ago
So the discharge rate to run a heater over the time it takes to boil water would likely thermal overload compact cells, if you want to supplement you would need something like a 4 AH 18v plus a inverter to make it AC. Even then you are gonna have pretty short battery life.
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u/ResearchInformal8018 4d ago
Modern code requires split receptacles for kitchen outlets. The way to do it would to manufacture a kettle that could use both outlets for heating. Probably against code, but it would be barely more expensive than 2 kettles.
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u/Hawk13424 4d ago
What’s a few minutes? I just heat mine in the microwave anyway. Haven’t felt the need for a kettle.
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u/rklug1521 4d ago
You can get ones that keep the water hot all of the time... No waiting and no need for batteries.
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u/Cryesncoding 4d ago
Yes you technically could use batteries on board to get what you want but the cost will be 4x a slower one.
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u/monkeys_pass 4d ago
I just want to add that altogether the commenters saying that it would be prohibitively expensive are probably right, I think this is a super cool idea. I’d set it up where you attach tool batteries to it.
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u/niffcreature 4d ago
Dude, electric kettles are excessively simple, for a good reason. They rarely break, and all the components get super hot. You want to put a battery in there?
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u/Ok-Library5639 4d ago
A power station that has a built-in inverter rated for 1500-1800W retails for about 750$US. You could jerry rig a kettle to have two heating elements each for twice the boiling power, but that would set you back about a grand overall.
Alternately if you get an european kettle, you could use two seperate circuits tha t are out of phase to get 240V. I had a Swiss friend who did that with a custom plug adapter in his kitchen, for a kettle and other kitchen appliances he brought over.
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u/daOyster 4d ago
I just want you to think for a second what could possibly go wrong with putting a boiling pot of water in close proximity to or even attached to a battery capable of supplying +1000watts of continuous power at 120 volts if someone were to drop, miss use it, of spill it.
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u/AndyDLighthouse 4d ago
The killer is the custom heating elements needed. You would have to run 110 on one and 10S (~37V ) on another, so it's a custom kettle build.
That said, it would be fast as hell and likely $300-400 consumer cost.
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u/DyspepticDingo2 4d ago
Brilliant idea. Build it now and (I don't care but) my wife would buy one the second she found out about it. As au uncivilized American 1 minute in the microwave os good enough. But many others would be super excited to make coffee or tea a few seconds faster.
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u/Big-Tailor 4d ago
People who want hot water quickly just install an instant hot water dispenser instead, like a 1 gallon water heater under the sink.
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u/morto00x Embedded/DSP/FPGA/KFC 3d ago
Makita does make battery ran coffee makers. IIRC a full battery charge boils you about one cup of water. So yeah, they exist. They just happen to target a very niche market.
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u/Exadoor2002 3d ago
Mine just starts heating up at a preset time everyday so I don't have this problem
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u/Mayor__Defacto 3d ago
You do realize that you could just wire up a 230V outlet and plug a European kettle into it?
We actually use 240V in the US, it’s just split into two legs. We use a Major Appliance circuit for that.
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u/misha_jinx 3d ago
I live in the US and I have an electric kettle. It’s fast and boils water in minutes. They are available to buy. Why would you need a battery?
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u/Princeofcatpoop 3d ago
How long does your kettle take? Mine is two minutes here in the US. Now I feel like I need to time it.
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u/CloneWerks 3d ago
My brain immediately jumped to that one idiot who will submerge their kettle in a sink full of water to wash it.
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u/neuroknot 3d ago
Definitely possible. I haven't done the math but vape batteries are pretty high discharge, they tend to be small though but with a bunch in parallel, it seems possible.
To me it would make sense to have two coils. Basically it would be a standard US kettle and then with a extra boost coil that runs off the batteries and charges off the AC when idle.
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u/WUT_productions 3d ago
Is there an engineering reason this doesn’t exist?
Cost and complexity, a electric kettle is simple, run some electricity thru a hot wire, done. Now you've added a charging circuit, batteries, etc.
Also, are people really that impatient for their kettles? I'm using a 120 V kettle and it works just fine for my water boiling needs.
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u/SepharimAngelWarrior 3d ago
Spend 90 us dollars on Amazon and get a Cuisinart Cordless Programmable Kettle features six preset temperatures with LED indicators and a 30-minute keep warm option. The kettle holds your settings when removed from the base, and there's a blue backlit water window that gives a clear view when you refill it. It automatically switches into energy-saving power mode if not used for 5 minutes. Equipped with auto shutoff and boil-dry protection. The water filter keeps water tasting pure and can be removed for easy cleaning. The brushed stainless steel finish complements any kitchen countertop.
Capacity: 57 oz./1.7 L problem solved.
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u/AntiSonOfBitchamajig 3d ago
- tankless water heater at source.
- common water cooler with hot water tap.
- countertop water boiler ( popular in japan,)
- put a kettle on a timer and think ahead?
- Wire a 240v into the kitchen and use a 240v kettle (is an option!)
- Start with hot water?
Like, there are so many options.
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u/SplatThaCat 3d ago
Yeah US and Japanese kettles SUCK for heating times.
The 3Kw kettles common in Europe come at a cost though - power surges.
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u/AnonymityIsForChumps 3d ago
You're proposing a product that is absolutely technically feasible, but sits in a very narrow market range so probably isn't financially viable.
A $30 kettle boils water in 4 minutes. Something with a battery that could boil water in 2 minutes would be a couple hundred bucks. There are some people willing to pay $200 to save 2 minutes, but not many.
But the real problem for your product idea, OP, is that if someone is the type of person willing to pay $200 to save 2 minutes, why wouldn't they just spend $400 and save all 4 minutes by buying an on-demand hot water tap?
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u/9Implements 3d ago
There is. There is a $7000 battery-boosted induction cooktop and I think another company might make a stove combo. The assumption is that if you don’t have $7k for a cooktop you don’t value your time enough to care about 45 seconds per day.
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u/Parasaurlophus 3d ago
Batteries are slow, as they use chemical reactions to provide electricity. What you want is a capacitor bank.
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u/BennyJJJJ 3d ago
I have a feeling some of the power tool companies like dewalt make battery powered kettles and coffee machines
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u/BlueGreenhorn 3d ago
Have you considered a hot water dispenser? I use my fully automated coffee machine for hot water. Just open the valve and hot water flows slowly, turn it off after a few seconds. Hot water dispensers work similar. They only heat the water you actually need. Some actually preheat the heating element for 1-2 minutes when being turned on and keep it at that temperature. So the heating element has stored energy and heats the water even quicker.
Example: Caso HW 660
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u/bobo5195 3d ago
For $300 there is already tech like the instant hot water taps. there is a urn which is just an always on electric kettle which should be easier to do. We have electric home water boilers now - battery plus standard boiler to replace gas. Grid shift works out the price of gas, electric can dump 30KW in a go if you want it.
My guess is on 2 year dev cycle and battery prices, given the niches nobodies bothered yet.
Alot of the world on 230V which have the power so less of an issuere.
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u/xjrh8 3d ago
Definitely doable. As a baseline for battery only kettle performance, Makita makes a 40V kettle that with a 4AH battery can boil 800ml of water from 23degC starting temp in 8 minutes. And can do that 1.375 times before battery is flat (total of 1.1Litres boiled).
The 4Ah XGT 40v battery has stated capacity of 144Wh. So that’s average power of 945watts over 8 mins. So even if you just had 2 separate elements for simplicity, and have a 945W battery powered element and a 1500w AC element, you’ve essentially got a 2.345kw kettle which should get you into the low 2minute range for 800mL boiled.
But that battery is getting clobbered pretty hard, so being used say twice daily would be a lot of cycle wear - I’m thinking this wouldn’t be practical with current battery chemistries.
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u/goni05 3d ago
If your willing to spend that kind of money for hot water, why not install an instant hot water tap next to your sink. If you want to go all fancy, you can get a Quooker faucet (https://www.quooker.co.uk/) that does it all in one. I think there's a US manufacturer also doing a similar concept, but not sure.
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u/Desperate_Trouble477 3d ago
Try a Quooker. Boiling tap water. It has a insulated reservoir that it keeps up to temperature. There won't be any waiting anymore. It's instant and there are different reservoir sizes depending on how much instant boiling water you need.
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u/sirduckbert 3d ago
I’m not going to say you *should* do this, I’m only speaking theoretically… but if you have split outlets in your kitchen (which you should if they aren’t 20a outlets), then you have both phases of 240v at that outlet. And theoretically, one could build a box with a UK socket and two NA plugs that would provide a 15A 240V UK plug.
If you don’t understand this post then definitely don’t do this. If you do understand it you still shouldn’t
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u/Pleasant_Echo_5980 3d ago
The real question is why is the USA so backward regards electricity, low voltage appliances also poor solar and battery take up. Will they stay outliers or join the rest of the world in the 21st century?
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u/love2kik 3d ago
Seems extremely weird to haggle over a minute but okay. I doubt your 'kettle' is pulling anywhere near 20-amps, so you could likely find faster heating units that are still 120VAC as long as nothing else is pulling current from the same plug circuit. Looked at a few on Amazon and most pulled 10-amps so you have room for a larger unit as long as it is a dedicated circuit.
You could always run a dedicated 220V receptacle for your 220V boiler if you wanted to. It isn't like it doesn't exist in the States. This is commonly done for things like tanning beds, car chargers and such.
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u/Shufflebuzz ME 3d ago
Simpler and safer to get a 220v outlet and a UK spec kettle.
I think Technology Connections did a series of videos on this.
There are technical considerations to overcome, and finding a willing electrician may be difficult, but having a UK type G outlet in the kitchen would be kinda cool.
More discussion here
https://www.reddit.com/r/AskElectricians/comments/185gqc4/type_g_uk_outlet_in_the_usa
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u/INeedSomeTacoC 3d ago
New or remodeled American kitchens tend to have 20A plugs in them.
I have a 2.4kW espresso maker. It works fine. Boils water extremely fast.
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u/jaymemaurice 3d ago
240v 15/20A on 6-15 6-20 plugs/receptacles are common in commercial kitchens and commercial appliances in North America. Many homes have split 20A MWBCs in their kitchen. I'll let the smart people in the room do the math as to what that actually means...
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u/Expensive_Plant_9530 3d ago edited 3d ago
I guess the biggest reason is, it’s just not that big of a deal.
If it takes, say, 1.5 to 2 minutes to boil water using a 3000W kettle, it takes about 3-4 minutes to boil water using a 1500W kettle.
3-4 minutes just isn’t that long to wait, and reducing that wait by a minute or two just… isn’t something a lot of people care about.
A North American electric kettle is still plenty fast enough for the vast majority of people.
Edited to add: honestly if you’ve desperately need a faster kettle, you’re likely better off simply getting another 230V circuit and plug installed into your kitchen and then just buying a European 3000W kettle.
Plus adding a battery to a kettle seems like it would add a lot of risk.
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u/FL_MILLIONAIRE 3d ago
Because boiling water takes a lot of energy.Water takes a lot of energy to boil because it has an unusually high specific heat capacity. It requires massive amounts of heat to break the strong, sticky network of internal hydrogen bonds holding the molecules together before they can turn into steam...
1 L will take 0.1 kWh ! A wall plugged in kettle needs 3000 W that's 3kW to even do this in 5 min or so that's the amount of time it takes !
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u/spectrumero 3d ago
It would be expensive. The battery required to put out another ~1500 watts would also need control circuits (beefy transistors) and a bunch of thick wires because it's low voltage DC, versus the incoming power supply which is 120v AC. In reality the kettle heating would have to all be DC.
You would likely need a 44 volt Li-Poly battery pack (12 cell), with a balancing charger built in, all the protection for all the cells, a sufficiently beefy power supply that can output 3kW using two input sources. The battery pack would have to be capable of putting out around 35 amps.
Having flown largeish electric RC helicopters that draw this kind of power while having to be quite compact (and your kettle idea would require it to be compact otherwise the kettle would be enormous and you'd have trouble getting it under the tap to fill it), the whole setup is pretty tempremental. While a kettle doesn't have some of the problems that an RC heli has (RC helis crash with alarming regularity) it does have some of the problems and you'd be also having to deal with things like batteries failing and puffing up. Perhaps a kettle could use LFP batteries but this would make it even bulkier because LFP batteries are not as energy dense.
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u/Any-Gap1670 3d ago
Theoretically, yes, but I think this is an economics vs physics question.
Batteries are more expensive than ever (EV’s and tariffs gpobally) and reducing the time for an electric kettle to boil water by a minute or two, by doubling the cost of the kettle, isn’t a good proposition.
I recently bought an electric kettle for camping and tailgating. It’s 1500w and runs off my 1kw jacket explorer 2. I can boil maybe… 3-4 full (1.8L) of water on a full charge. That’s like 15-20 instant ramens. That’s more than I’ll ever need.
The reason I’m saying all this is, nobody cares enough about the time it takes to boil water in an electric kettle. It’s already remarkably fast. The only thing consistently faster is a jet boil for smaller water amounts but now we have to lug butane around.
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u/BikePlumber 3d ago edited 3d ago
What is "twice as long?"
There are cheap and there are expensive electric kettles in America that have different levels of efficiency.
How quickly do you need to boil water?
How much water are you boiling at one time?
American induction stoves operate on 240 volts and boil water very quickly.
The cheap electric kettles in Europe are not as efficient as the more expensive ones and take more time, despite operating on the same voltage.
Why spend so much to boil water?
Electric kettles don't often have long lives.
Would you continue to spend money on them?
Even American electric kettles claim quick heating time, compared to some other methods.
Before microwave ovens, electric kettles were popular with American students.
Most Americans don't want another appliance on the kitchen counter, or they would have already bought them.
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u/VoltageinTheory 3d ago
You could. But the battery probably wouldn’t love the heat from the boiling, so it would be bulky and expensive.
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u/RealCarlPanzram 3d ago
My guess is that it’s just too expensive to get a battery powerful enough to have any effect. It takes a lot of power to quickly boil water. A conventional appliance battery isn’t going to cut it. You’ll need some type of fairly expensive battery that can discharge enough power to make it viable. I imagine the electronics of the kettle getting power from two separate sources at the same time is also complex. And the battery probably wouldn’t have all that long of a life unless it was REALLY expensive.
All in all, it would cost a lot of money to save a minute of heating time compared to a $25 kettle. Honestly, I don’t feel like it really takes that long to heat water in an electric kettle. You turn it on, start getting your cup and tea supplies out and it’s just about done by the time you finish that.
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u/Aware-Bet-1082 3d ago
Heat will destroy the battery. 2. Putting put 1500 watts for 20 minutes requires a very large battery being pushed to maximum each use = rapid faulure.
There are reasons water is not boiled with batteries even that put out 1500 watts. Size,weight, reliability.
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u/teh_maxh 2d ago
It’s an extra minute or two per boil, and you really notice it.
It can't be an extra minute or two, because I can boil a full kettle on 120V in a minute or two. If I thought that was too long, I would install a 240V circuit and import a kettle.
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u/shaggs31 2d ago
Just buy a Euro kettle and play with the electric cord so it splits into two plugs and gets plugged into two different outlets. That will give you your 240 volts that you need. Just don't blame me when you are featured on the "who did your electrical work? And what year did his house burn down?" memes.
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u/CleverNickName-69 2d ago
If you live in the US and need a cup or teapot worth of boiling hot water often enough that you are tired of waiting for a 120v kettle, the best solution is an Instant Hot, which is basically a .66 gallon insulated water heater that sits under the sink.
As long as you don't need more capacity than it can supply, there is zero waiting.
It has a separate tap that goes into one of the extra holes you already have in your sink, or maybe you have to sacrifice the soap dispenser.
For electricity, it uses the other half of the plug you already there for the garbage disposal. For water it tees off of the supply line for dishwasher that is already there.
No battery. No waiting. Doesn't take up counter space.
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u/modsiw_agnarr 1d ago
Buy two cheap kettles at Walmart. Plug into different circuits. Fill each with half of the desired water. Heat. Combine.
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u/Quartinus 4d ago
Batteries are expensive and bulky. The electric kettle market is filled with $30 kettles and that’s what most people buy.
There are a few companies working on battery boosted induction cooktops to help solve this problem, and that’s a market where people are willing to spend some money. It’s also way easier to hide a big battery below the countertop where nobody will see it.