My car charger can boil water really fast [video]

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

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/

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.)

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.

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.

I'm in the midst of a kitchen remodel (in 120V land).

I decided to pull an extra 240V line to the countertop explicitly for a tea kettle, which I have not purchased yet but seem to be available from Amazon UK for ~2x the price of an ordinary US-market kettle.

The most disappointing thing so far is the short list of kettle options that ship from the UK to the US.

Also not sure if I should get a UK receptacle (this would probably offend the bldg inspector, so I might swap post-inspection), or just rewire the kettle itself with a standard US (240V) plug.

FWIW, the extra wire + breaker cost was about $100. I expect to pay another $30 or so for the receptacle or appliance wire, and a bit over $100 for the kettle (and its replacements every few years). Not the least expensive option, but not too bad.

Personally I would just wire some NEMA 240V outlet and then have a separate adapter with a pigtail of that receptacle type and a workbox with the UK receptacle. It's a little unwieldy, but it puts the questionable hackery outside the realm of the building inspection at least.

Whether it's actually safe I though, that I am curious. Obviously the kettle can get the 240V potential it expects, but the neutral is center tapped out of the split phase transformer, right? Not sure how people wire this. (Doesn't the neutral wind up having to be one of the hots instead?)

Hmm, yeah! I hadn't thought much about the differences between UK and US 240VAC service.

In the US, it's 240V 60Hz, split-phase with center-tapped neutral, and an independent ground wire.

In the UK, it's 240V 50Hz, single-phase with independent neutral and ground.

Frequency difference should be within design tolerance. and if my EE memory serves, the phase difference should be acceptable -- just measured from a different zero reference point. The neutral from the wall would be unused, and the ground would be wired as usual.

I'll think this through thoroughly though, I was definitely glossing over those details, so thank you!

Basically my concern is, ordinarily the potential from neutral to ground would be roughly 0V with some slack. In this case, though, the potential from neutral to ground would necessarily be 120V. I have no idea what the implications of that may be, but it seems important.

I think it works if the US neutral is left unused (terminated in the electrical box).

E.g, something like this:

  (US proposed)    (UK kettle)     (UK standard)
  (2-phase)      ┌─────────────┐   (1-phase)
                 │             │
  L1 120V 0° ────┼─ Hot(240V) ─┼── Hot 240V 1ph
                 │             │
  Neutral ───X   │             │
                 │             │
  L2 120V 180° ──┼─ Neutral ───┼── Neutral
                 │             │
                 │             │
  GND ───────────┼─ GND ───────┼── GND
                 │             │
                 └─────────────┘

I think this is right, but I'm not 100%. The kettle should get what it needs, but I'm less certain whether a GFCI or ArcFCI breaker would have opinions that must be accounted for. I'll check with someone more qualified than myself to be sure!

Yes I understand. But what I'm saying is, normally neutral and ground would have roughly 0V potential, but in this case the UK neutral and UK ground will have 120V potential between them, because the US 120V second phase will have 120V potential to ground. (It bears noting that I am just a random guy and not any kind of expert. No formal education or credentials relating to electricity whatsoever.)

I think you're thinking about it on the kettle side, and I was thinking on the breaker side.

I think the kettle side would not care. It may be a ground fault in UK wires, but the kettle has no reason to detect it, and nothing sensitive enough inside to care. If I'm wrong, I'd expect to know shortly after starting the very first use. :)

You guys know he talks about this 4 minutes into the video, right?

See also: https://diy.stackexchange.com/a/315031