Induction Cooking info and experience.

[K_V_B]

Originally Posted by Statistical

Yeah especially as boats move to 48VDC.
The big challenge though is DC market is tiny (offgrid, rv, boats, etc). Any one of them can use an AC "powered" induction cooktop but the home market can't use a DC powered one. So it means building a niche device in much smaller numbers. Beating the economies of scale will be tough. It could be something that just never catches on because it is cheaper and easier to just grab a readily available AC powered unit.

One market is countries that are still in the process of electrifying. A google search for DC induction hobs turned up a product from India that is supposed to operate on solar power, and that is intended to help rural Indian families stop being dependent on expensive cooking fuel.

Couldn't find out however if it is really DC though.

Another interesting product I stumbled upon is this:

https://www.newrcompany.com/

Also not cheap, but otoh if something like this allows one to switch to electric cooking without having to upgrade your boat's electrical system it would make sense for a lot of people.

[CaptainRivet]

Originally Posted by Statistical

Or you know you could just measure the power factor using your multimeter and stop guessing and making blanket wrong statements.

Your claim was induction cooktops have a low power factor despite every piece of reporting and self testing showing the exact opposite. You then spent 3 posts detailing every aspect of your electrical setup except the measured power factor.

Yes thats just the induction cooktop on both inverters, how i measured and how all crosscheck lined up.
no theory or electronic studies, just what it results in... so explain me whats the theory that causes this and whats the electrical term used for that, that the pure HF inverter needs 600W additional on the pulsing one.

Not the classical answering with a question.
Happy to learn.
And most likely its just the same game then what one company calls a code 0 and the other a reacher but both sell the same sail.

[Fuss]

Originally Posted by Statistical

Stop. Just stop. None of that is correct.

i agree… i’ve been running induction since 2012 and it works fine…. what a load of complication being banded around… i mean look at this thread … what a waste of time… and look at the posts …. from someone who knows nothing!

[CaptainRivet]

Originally Posted by K_V_B

What is needed for boats is an induction hob that works of DC...

Induction cookers internally rectify the AC to DC, and then convert it again to high frequency AC to drive the coils that heat up your pans.

So on a boat you are converting three times. DC -> AC -> DC -> AC. And you lose each time.

There is a company in the US that produces induction hobs that have a battery included in the DC circuit. The idea there is to limit the peak demand at the AC side, so that retrofitting induction cooking in kitchens that do not necessary have the required heavy power circuits is possible.

I think if you would scale that down, and get rid of the AC side you might have a good product for on a boat.

RV market is huge, don't underestimate that and developing a real DC cooktop (if possible have no glue as i don't know how that exactly works) would be easy to make economic of scale, especially if you can sell for a higher price because a much smaller inverter would do it then.
On the other side with 48V a 5kw inverter doesn't cost much and you are set with all household appliances, not only the cooktop and thats why they don't do it.

[Pete7]

Originally Posted by CaptainRivet

So explain why the pulsing needs 600W more on the HF and 350 more on the victron which is a hy rid LF/HF?
Its is obviously reactive power loss or other call it phantom load or ?? ...doesn't matter how you call it, its there and causes HF inverter to frequently die.

I don't think you have got the idea of a pulse load. It is not as you have referred to above a 100% load, it can be much less and one way that temperature is controlled at lower temperatures. Have a look at the table I posted in 163 to see a good example.

Pete

[CaptainRivet]

Originally Posted by Pete7

I don't think you have got the idea of a pulse load. It is not as you have referred to above a 100% load, it can be much less and one way that temperature is controlled at lower temperatures. Have a look at the table I posted in 163 to see a good example.

Pete

Hi Pete,

I know what pulsing on induction hob means and you have basically 3 kinds/types, lets say all have a 2kw burner:

Type 1 and the worst: the burner pulses always with its max power 2000W, the difference in the levels 1 till 10 is just frequency it pulses eg 1 is one pluse per second and level 10 is 30 times a second and thats fixed.

Type 2 is the same.then typ1 but temp regulated means it sends 5 pulses with 2000W measures the temp and pulses again, number and frequency of pulses depends on temp and level 1 till 10 you set but each puls is always 2000W.

Type 3 has actually some levels means level 1 till 3 is 400W and at 1 it pulses with 400W for 3 sec and pause for 3, level 2 is pluse wit 400W for 5sec and 3 sec break and 3 is pluse constantly with 400W. Then level 4 and 5 is the same just with 800W and so on. Level 8 till 10 is then 2000W, just with different frequency. Pete your table in 163 shows thats a type 3 too.

The regulated 2000W burner on the Bartscher have a constant current load, means Level 1 is 1.2A and on till the pan reaches 60 degress, then it switches off and on if temp falls below 50 degrees. Same on all levels with or i can directly set a temperature to which it should heat the pan or pot and it heats it up with eg level 5 or 4.5A and keeps it there means it regulates the current down from 4.5A to 2A to keep it there.

The Rommelsbacher i tested was a type 3 pulsing one, so already the best of the pulsing ones.
So the Rommelsbacher pulses on level 10 with 2000W and if you measure at the power plug of the Rommelsbacher you will find around 8.5-9A with 230V=1950-2070W. (Yes on level 5 it will be only 1000W or 4A at 230V)
And now while its running on level 10 measure directly on the input 12V terminals of your HF inverter and you will find it draws 210A at around 12.8V or 2680W or appeox 600W more and the internal temp rises as the cascading mosfets get hot as the load per cascade is not even due to that pulsing.
With the Type 3 it does this 2680W only on level 8 till 10 but with typ1 and 2 it will need the whole time 2680W or even more. Thats because the regulation of the HF is screwed up by the pulsing and the inverter needs more power to keep it stable and that more power is lost in heat. Some call this phantom load, some reactive power and other...fact its there and even worse with mircowaves and that what kills the HF inverter.
The victron kept it much more stable and did only need 350W more.

[Pete7]

Originally Posted by K_V_B

What is needed for boats is an induction hob that works of DC...

Induction cookers internally rectify the AC to DC, and then convert it again to high frequency AC to drive the coils that heat up your pans.

So on a boat you are converting three times. DC -> AC -> DC -> AC. And you lose each time.

This one looks a bit cheaper. However, then you need to run long 24 or 48 volts from the batteries to the induction hob. Much easier to run 240v anywhere in the boat.

https://www.alibaba.com/product-deta...AAAC8B2784C2FD

[mako]

The photos of the 24/48VDC induction don't jive with the description. Those wires look like either 12ga or 10ga at most, so that would limit it to about 1kw, not the 2.2kw it reports. What size wires do you run to your 2kW inverter?

I agree with @Pete7, just stick with a 120/230VAC cooker.

Plus the red is butt ugly.

[aybabtme]

24/48V... and 50-60Hz? Doesn't make any sense. Just buy a better inverter.

[Dockhead]

Originally Posted by K_V_B

What is needed for boats is an induction hob that works of DC...

Induction cookers internally rectify the AC to DC, and then convert it again to high frequency AC to drive the coils that heat up your pans.

So on a boat you are converting three times. DC -> AC -> DC -> AC. And you lose each time.

There is a company in the US that produces induction hobs that have a battery included in the DC circuit. The idea there is to limit the peak demand at the AC side, so that retrofitting induction cooking in kitchens that do not necessary have the required heavy power circuits is possible.

I think if you would scale that down, and get rid of the AC side you might have a good product for on a boat.

I disagree, certainly for any boat with less than 48v DC system.

Two reasons:

1. It is worth the small conversion loss for the greater efficiency -- and safety -- of transmitting a couple kW (or more) some distance at 230v. Even at 24v DC you are dealing with up to 100 amps or even more, you don't even want to think about it at 12v.

2. Standard household equipment is vastly cheaper and better than some exotic custom low production DC induction job.

[aybabtme]

Searching for a 48V induction stove top is a waste of time. Say you use a 1.8kw stove for an hour at full power everyday (a wild exaggeration), that's 1.8kwh. If you save 10% efficiency on the conversion loss, you're saving 180Wh, and got a weird chinese fire hazard cooktop instead of an off the shelf one. Just to save 180Wh.

180Wh on some boats is a big deal. But if you have a 48V bank and electric galley, one would assume you're not on a shoestring power budget where 180Wh changes anything.

Optimizing for DC-AC-DC conversion losses makes sense for high duration high load items. Not on a cooktop.

[Hhew]

I have an Empava 2 burner unit that fits exactly on top of my Eno 2 burner gimbaled stove. I retain full propane capability as backup with the induction gimbaled. 110vac via a 3k inverter. With silicone pads and high-side pans, I am able to safely cook up to about 5-6 Beaufort, depending on the wave dynamics. On a recent passage in the W Caribbean with 18-26kts on the beam, we cooked scrambled eggs, bacon, beans and rice and chicken, all no problem. A pot of spaghetti will use about 1200W for maybe 20 minutes, with the sauce on burner #2 at 900W for maybe 5 minutes. Cooking is only a small fraction of the total energy budget but I’ve spent the past 6 months living full time on the boat, combination at sea/anchored/dockside and cooking power has never been an issue. One big advantage in hot weather areas like Florida and the carib is the ability to cook a meal without significantly heating up the boat. Overall it makes the boat much more livable.

Edit to add: for oven functions, we have an a Faberware air fryer on the countertop which we strap down when under way. We made chocolate chip cookies while at sea and it worked great.

[Pete7]

Originally Posted by Hhew

Edit to add: for oven functions, we have an a Faberware air fryer on the countertop which we strap down when under way. We made chocolate chip cookies while at sea and it worked great.

You could make ice cream in the air fryer then

https://allwaysdelicious.com/air-fryer-fried-ice-cream/

[Pete7]

Originally Posted by mako

The photos of the 24/48VDC induction don't jive with the description. Those wires look like either 12ga or 10ga at most, so that would limit it to about 1kw, not the 2.2kw it reports. What size wires do you run to your 2kW inverter?

I agree with @Pete7, just stick with a 120/230VAC cooker.

Plus the red is butt ugly.

I am running 50mm2 cables with a 2kW inverter. Round trip is no more than 2m of cable from battery terminals to inverter and back. I think 50mm2 is equal to 1/0 AWG, or at least close enough for government work. Generally below a 120A current. We don't observe any pulsing issue that CR keeps going on about.

Other thought, what happens if it goes poof* With a 120 or 240v induction hob you can nip into town on a Sunday morning and probably buy a replacement. Your crew are not going to be pleased when you say you have ordered a 48v version via Ali X and it should arrive in country next month. We carry a spare inverter, a spare double hob and single hob even on a 12v boat.


*the word has several different meaning in the UK

[s/v Jedi]

Pete touches on the second important factor of why induction cooktops should be AC powered: it is the norm.

When you require DC powered versions for scenarios like starting a colony on Mars then it may be worth it but for boats this isn’t the case.

Simplified 12AWG wiring and availability are enough reasons to eliminate DC powered options from consideration.