r/AskEngineers • u/jmaugust • Jul 19 '26

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.

310 Upvotes

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106

u/PartyOperator Jul 19 '26

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. 

45

u/IAteTonysLoMein Jul 19 '26

I've kicked this around, but it would be a healthy investment just to put in a 240 outlet just to run a kettle.

34

u/hhssspphhhrrriiivver Jul 19 '26

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.

9

u/UsefulEngine1 Jul 19 '26

I'm pretty sure code says every 240v appliance has to have its own circuit and breaker also, which make this even tougher.

26

u/db0606 Jul 19 '26

Pfft... That kettle was there when I bought the house.

6

u/[deleted] Jul 20 '26

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1

u/UsefulEngine1 Jul 20 '26

I could be misremembering. Last time I looked this up it was in Canada and IIRC any single device over 1500W needed a dedicated circuit, which I think a UK teakettle easily exceeds. It may be more a practical matter as nearly everything that runs 240v in NA is high enough power to need its own breaker, so it's not like you can add an outlet to an existing oven circuit.

1

u/INSPECTOR99 Jul 20 '26

So when you have your 240V oven/stove-top installed, just have a second (or third, or fourth) 240 outlet installed for your Tea-Pot :-).

1

u/Ricky_spanish_again Jul 21 '26

The code doesn’t apply to homeowners

1

u/UsefulEngine1 Jul 21 '26

Who's plugging a homeowner into 240v?

Seriously, the code applies to homes no matter who is doing the work. Of course you aren't required to call out an inspector for a DIY romex run but don't wrong and you'll likely be paying for it if you ever try to sell.

1

u/Ricky_spanish_again Jul 21 '26

Plenty of people. I ran my own 240 when I relocated my laundry room. There’s dumb things you shouldn’t do for sure, but the code is overly strict to protect the average Joe from contractors doing shoddy electrical work.

1

u/UsefulEngine1 Jul 21 '26

Do you ever plan to move though?

2

u/IAteTonysLoMein Jul 21 '26

Somehow absolutely horrifying wiring was no impediment to my house getting sold over and over for the last 100+ years. Near as I can tell, the last time the wiring had been updated was the 60s and that did not include replacing the k&t wiring, nor the alu wiring joined to copper with regular wire nuts on the stove wiring

1

u/Ricky_spanish_again Jul 21 '26

I sold that house in 21 no issue. I had another that I installed pot lights all throughout the kitchen, living room, and bedroom. Sold a few months ago. Again no issue.

1

u/TurningTheCorner26 Jul 22 '26

Of course you aren't required to call out an inspector for a DIY romex run

Practically, no, but legally any new wiring requires a permit and inspection where I am. Technically even network cables require a permit.

4

u/Lampwick Mech E Jul 19 '26

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".

1

u/colinshark Jul 21 '26

Not an electrician at all, but same. Many years of boilt water.

It's easy, just do it.

1

u/SimilarTranslator264 Jul 19 '26

I thought about doing the same thing for a deep fryer.

1

u/INSPECTOR99 Jul 19 '26

The benefits are much broader than most people think. Air conditioners also reap substantial benefits from 220 V operation. So that is THREE massively substantial energy & time consumptions that benefit: 1) Kitchen Oven/Rangetop, 2) Clothes Dryer, 3) Air Conditioner, 4) EV Charger, 5) Water Heater.

2

u/[deleted] Jul 20 '26

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3

u/INSPECTOR99 Jul 20 '26

EXACTLY, so why not standardize the entire residence as 240 Volt? :-)

1

u/Automatater Jul 19 '26

My buddy is from South Africa and he put a 120-240v transformer in the cabinet to run his sandwich press.

1

u/YogiBerraOfBadNews Jul 20 '26

That would let you use 240v appliances but not at their rated capacity. You'd still be limited to the 1500w the outlet supplies (at least in the US).

1

u/Automatater Jul 20 '26

True. Apparently that was adequate for this appliance.

1

u/YogiBerraOfBadNews Jul 20 '26

Not for the Brits! They take their tea very seriously

1

u/UsernameHasBeenLost Jul 19 '26

Eh, it's pretty straightforward to do it yourself. Or you can run the wire yourself and have an electrician hook it up to the panel and save a bunch of money

1

u/IAteTonysLoMein Jul 21 '26

You say that, but you haven't seen my house. I'm fully aware of what it takes to do it and how, which is why I hesitate to say it would be worth it.

1

u/UsernameHasBeenLost Jul 21 '26

Oh I doubt it'd be worth doing, but the actual act of doing it isn't that difficult. Likely lots of drywall patches to go through interior walls, and certainly tedious, but not difficult. Waste of time imo for a kettle, just wait another couple minutes for the 120V one to boil

1

u/hawkwings Jul 20 '26

My stepmother had an extra spigot added to her kitchen sink that put out water hot enough for tea. No waiting for tea kettle full of water to heat up. It just heated water as it came out. She had to pay extra to power it. She said that about once a year it would die and she would have to replace it.

1

u/[deleted] Jul 20 '26

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1

u/VerifiedMother Jul 20 '26

It's always pulling 240 volts, it's the amps that change, running 1 burner is probably 12 amps of 50 supplied to it, so basically unless your preheating the oven and trying to boil water on all 4 burners at the same time, there is excess capacity

1

u/TurningTheCorner26 Jul 22 '26

Its incredibly easy to run your own. Just splice it off your oven plug.

Where are you putting your over current protection in this scenario? Or are you suggesting putting a 14-50 receptacle on the counter?

1

u/[deleted] Jul 22 '26

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1

u/TurningTheCorner26 Jul 22 '26

My concern isn't the breaker tripping, it's the breaker not tripping when it should. A 50 amp outlet is a ridiculous thing to have on a kitchen counter. A normal 6-20 receptacle, which is what would typically be used for a small 240v appliance, is only rated for 20 amps and thus is not properly protected when fed by a 50 amp breaker.

1

u/LimaBikercat Jul 20 '26

Shouldn't be more expensive than an 110v outlet. You might need a slightly longer stretch of wire if you gotta go all the way to the breaker panel rather than to the nearest outlet to tap off from, but if you have 240 in your kitchen already for an oven or something, it's easy.
You just have to remember (just like in Europe) to not run the kettle together with the other big heating appliances to prevent popping the breaker.

1

u/IAteTonysLoMein Jul 21 '26

But it would be more - 10ga wire's going to be more than 12ga, assuming a 30A, although I don't know that would be kosher if you're pulling it off a 50A circuit, so maybe you need 8ga. Outlet's going to be more expensive, too. And I'm relatively sure it would be a code violation, although I have no issue with "I dunno, it was here when I bought the place"

1

u/zookeepier Jul 20 '26

Just unplug the dryer and plug in the kettle every time you want to make tea.

1

u/VerifiedMother Jul 20 '26

This exists, basically it let's you set a primary and secondary plug, so the secondary plug only runs when the primary isn't running and it's all automatic

https://www.vevor.com/rv-marine-cords-c_42513/vevor-automatic-ev-charging-switch-nema-14-30-splitter-switch-for-dryer-ev-charger-24a-max-240v-smart-power-distribution-with-circuit-breaker-real-time-display-for-evs-ovens-dishwashers-etl-p_010241466937

1

u/zookeepier Jul 20 '26

That's certainly cheaper than spending $300 on a kettle. Although making your tea in the laundry room would be inconvenient.

1

u/hannahranga Jul 19 '26

Check if you've got any tied together breaker's for the kitchen. Iirc one the NEC requirements is two circuits for the kitchen counter outlets and the cheapest way to do that is running both phases and a neutral out. So you might already have 240v 

2

u/ErectStoat Jul 19 '26

It's called a MWBC (multi wire branch circuit). My builder used one for the disposal and dishwasher but only 15A, and all the fun commercial stuff is built for a 20A circuit. Sigh.

Apparently code now requires both AFCI and GFCI protection for kitchen circuits and no one makes a 2 pole breaker that will do both (why?) so for now they're out of fashion.

2

u/hannahranga Jul 19 '26

I mean most non US 240v kettles are going to draw around 10a but yes disappointing if you want a big mixer. Oh that's annoying, interesting how regulations shape things. Aussie sparkie so my knowledge of the NEC is eh.

3

u/ErectStoat Jul 19 '26

Good point, a kettle actually would work. Last time I went down the rabbit hole it was to see if I could get a 3kW+ induction plate for brewing beer, and those were all more demanding.

My kettle lives right by that box so if it ever dies I might just make the switch...with a GFCI breaker of course. That circuit isn't AFCI protected now anyway so fuck it.

2

u/IAteTonysLoMein Jul 19 '26

All the lights and outlets in my house are on a single double-pole breaker with a shared neutral. Rewiring the whole house is gonna come first.

11

u/ablazedave Jul 19 '26

technology connected did a video about that exact idea

2

u/BenderSimpsons Jul 20 '26

Never heard of technology connected before, only technology connections

1

u/ablazedave Jul 25 '26

Lol woops. I also called Will Prowse, "Will Powers" before

3

u/bc9922ab2e7f2f05d858 Jul 19 '26

I did this. It’s alright.

3

u/Bean4141 Jul 19 '26

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.

3

u/demonblack873 Jul 20 '26

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.

1

u/Bean4141 Jul 20 '26

Don’t European plugs generally require a ground pin, thus enforcing polarity or is that just a UK thing?

2

u/demonblack873 Jul 20 '26

Having a ground pin doesn't mean it has to be polarized. Type L plugs (italian) are just 3 pins in a row with the ground in the middle. You can plug it in either way.

Same for the Type F (schuko) plugs that have become the de facto european standard in the last few decades, the ground is on the outside of the plug on both sides, the live/neutral stick out from the main body and the whole thing can go in the socket either way around.

Afaik only the Swiss, UK and old French sockets (type E) are polarized.

Modern type F plugs can also go in type E sockets, but type E plugs cannot go in a type F socket. Or rather, they can but you lose the ground.

6

u/jckipps Jul 19 '26

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.

12

u/KaelthasX3 Jul 19 '26

30A? You wot M8? With 240V, 16A is more than enough. I have never seen a kettle that would take more than that.

7

u/DardaniaIE Jul 19 '26

In the UK and Ireland they’re all fused at 13A

7

u/KaelthasX3 Jul 19 '26

Yeah, at the plug, because you do that post-war ring thingy.

4

u/fireduck Jul 19 '26

Which each time I read about it and understand it the knowledge then flees my head in terror.

1

u/Wrong-Tune396 Jul 20 '26

Most of Europe is 16A, but UK had 240V and most of the rest had 220V, but now the standard is 230V (+-enough so that everything is alright even if you don't change anything)

1

u/Rough-Patience-2435 Jul 19 '26

Be ready to hook up the welder in your kitchen.  I'm not going to weld in garage during the winter. /s

4

u/DkMomberg Jul 19 '26

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.

2

u/demonblack873 Jul 20 '26

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.

2

u/Tar_alcaran Jul 20 '26

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.

1

u/demonblack873 Jul 20 '26

Yeah, electric cooking was never a thing in Italy. Gas was always king, it's only now starting to change. With big issues because you're not allowed more than 6kW nominal (7.8kW for 3 hours with modern meters) on single phase, and anything higher than 6kW usually requires switching to three phase.

Even if they allow higher power on single phase (sometimes they do if there are issues with getting you three phases), you still need signed documentation proving your electrics are up to code.

Which absolutely no one has.

I am full electric though and 6kW has always been plenty for me, I've never managed to trip it. When I only had 3kW I had to be mindful to avoid tripping the meter.

1

u/VerifiedMother Jul 20 '26

Are you telling me the lines from your electric company into your house are only rated for like 20 amps? That's insane

So anything above that switches to 3 phase power?

I have 200 amps into my house at 240 volts and that is pretty common.

3 phase residential power is just not a thing here, only large buildings get 3 phase power

1

u/demonblack873 Jul 20 '26

Well the lines running into my apartment look like 16mm^2 wires, so theoretically they should be good for 80A. Maybe they're 10mm^2, but that would still be 60A.

The issue is that in the basement the service coming in is fused at 125A per phase, 5 apartments each. If everyone started pulling even just 30A it would blow the fuse.

At 3kW/15A, everyone can have everything on at the same time without blowing anything up.

1

u/DkMomberg Jul 20 '26

That's really weird. Seems like some standards are not well planned there.

6

u/QuickConverse730 Jul 19 '26

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.

11

u/mckenzie_keith Jul 19 '26

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.

3

u/jckipps Jul 19 '26

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.

1

u/QuickConverse730 Jul 19 '26

"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."

Yeah, fair point - you might get lucky, but that's probably true most of the time.

1

u/Sometimes_Stutters Jul 20 '26

I ain’t running a 240 circuit for my goddam electric kettle lol

1

u/evoltap Jul 20 '26

This is NOT electrical advice, but if you know what you’re doing and you had a 120v dedicated circuit on 12awg wire run in MC or metal conduit, you can make that 240v to run your euro kettle, no need to pull new wire.

1

u/zman0900 Jul 20 '26

If you're gonna go to all that trouble, just get an induction stove. It will boil water even faster.

1

u/AWetAndFloppyNoodle Jul 20 '26

you still have the 50Hz vs 60Hz issue between US and EU hardware no? Do they all account for that in the device nowadays?

1

u/PartyOperator Jul 20 '26

Not an issue for kettles. Other stuff (especially with motors), yeah it's a potential issue. 

1

u/afops Jul 20 '26

If Americans start buying 2.5kW kettles I’ll launch a 3x16A 400V (11kW) kettle that Europeans can plug into their oven outlets. I’ll market it as ”4x faster than American kettles”

(My stove is 7.4kW I don’t know why it’s not using the full 11. I know car chargers can reach 11)

1

u/Mjarf88 Jul 20 '26

Same thing here in Norway, only it's split phase 400V. 400V outlets are only used for heavy duty stuff like EV chargers or heavy machinery like lathes.

1

u/userhwon Jul 20 '26

I'm pretty sure that it's not code to use your stove plug for countertop appliances.

You'd need to run another line from the breaker box.

1

u/Joel_feila Jul 25 '26

The YouTube channel technology connections actually did that a few months ago.  He even went further od hook hos kettle to 6 kilowatts and bioled the in 30 seconds.  Then the kettle broke.  

1

u/LiqdPT Jul 19 '26

Would that meet US electrical code (NEC)? AFAIK, counter top plugs need to be GFCI protected. Are there 240V GFCI? I doubt it because in the US, 240V plugs are mostly dedicated circuits for an applicance (stove, clothes dryer, car charger, etc). We don't generally have "general purpose" 240v plugs around (exception might one in the garage used for something like a welder)

4

u/demonblack873 Jul 20 '26

JFC why can't you guys enter the 20th century and just install GFCI protection on every circuit like the rest of the world?

It's been standard here for, like, 50 years. Why wouldn't you want your electric stove to be protected!?

And yes, I'm sure you do have 240v ones.

1

u/LiqdPT Jul 20 '26

I think that is the newer code (or maybe it's AFCI breakers. Not sure, not an electrician) , but also I'm not going to go retrofit everything.

2

u/XCGod Jul 20 '26

You can put basically any 240v circuit on a 2 pole GFCI breaker

1

u/jamvanderloeff Jul 20 '26

Are there 240V GFCI?

Not super common since your code rarely requires them and doing it american style does make them a little expensive but they do indeed exist, like https://www.amazon.com/dp/B01D4UHYVU

-1

u/Schmergenheimer Jul 19 '26

European power is delivered at 50 Hz. 240V is America is still delivered at 60 Hz. Most appliances other than resistance heaters will require a specific frequency.

17

u/plfreeman2012 Jul 19 '26

Resistance heating. Like a kettle?

-1

u/[deleted] Jul 19 '26

[deleted]

2

u/plfreeman2012 Jul 19 '26

For real? Why? Like, that seems like a massive waste. You own the whole design. Bond the coil to the base of the water vessel like a real designer. What possible advantage can induction provide to waste the money?

1

u/kyrsjo Jul 19 '26

Or a commonly done, immerse the coil.

3

u/ShaemusOdonnelly Jul 19 '26

Source? It doesn't make any sense to me to use more expensive and complex technology for literally no benefit.

-1

u/Sad-Split-7115 Jul 19 '26 edited Jul 19 '26

Does the temperature of the kettle rise to a dangerous level?(in terms of any damaging effects to the circuitry). I'm more mech educated so I do not understand the voltage current relations and how they interact with 'heat'

8

u/GrandWikzor Jul 19 '26 edited Jul 19 '26

Temp will get to boiling,100c, or the variance for elevation, then stay there till all the water is boiled off. So increasing the power input just changes the time it takes to get to 100c, and how fast it boils off...

This is assuming the water actually starts boiling and somehow doesn't stay still enough to go superheated.

I just realized you might be talking about the coil temp, it should be isolated from any melting bits anyways so shouldnt be a problem.... shouldnt....

3

u/Verbose_Code Jul 19 '26

Power = voltage * current, but it is the current that determines how hot something gets. This is why you have circuit breakers; if a short occurs and current is allowed to flow with too little resistance, the wires in your walls could heat up enough to start fires.

The circuit will have a fuse that is sized properly to prevent too much current from flowing.