Induction Cooking info and experience.

[dannc]

Originally Posted by Jef & Marin, Netherlands

...
For boiling water we prefer an electric kettle:
- It has a gauge so you make exactly how much you need
- It stops automatically
- It is just a bit more efficient
...

One feature our electric kettle has over a stove top kettle is that it has a temperature setting. One can set the temperature, push the button and wait for the water to get to the set temperature. Not sure if the kettle is still accurate but it was when new. Lately, I just boil water for coffee and don't worry about setting a lower temperature. The wife does us the lower temperature setting most of the time.

We don't use the water level gauge in the kettle. Kinda hard to read and we just pour in the amount of water we need from the container that will hold the hot water. Much easier, faster, and we know we won't have too much water.

Later,
Dan

[sailcrazy]

Following. We have a Force 10 elect stove, with a glass top. Can the induction cooktop (single or double) be mounted directly on the glass top? What do you use for fiddles, to keep the pot in place? I've read putting a silicon mat between the stove top and the induction plate is a smart way to go......so far we've not found a silicon mat anywhere.

[s/v Jedi]

Originally Posted by sailcrazy

Following. We have a Force 10 elect stove, with a glass top. Can the induction cooktop (single or double) be mounted directly on the glass top? What do you use for fiddles, to keep the pot in place? I've read putting a silicon mat between the stove top and the induction plate is a smart way to go......so far we've not found a silicon mat anywhere.

Just put a portable unit on top. There are special silicone pads for this but I prefer larger ones that cover the whole top so as to make it easy to clean
Just cut them to size.

Single burner: https://www.amazon.com/gp/product/B01FLR0ET8

Double burner: https://www.amazon.com/gp/product/B07GB149V7

Silicone: https://www.amazon.com/gp/product/B0725GYNG6

[rgleason]

Thankyou sv/jedi.

Those look good.

1800w/12v=150ah so we need minimum LFP 300ah if discharge is .5, but .3 is better, so that would be have to be LFP= 450ah. We would also likely need a 2kw multiplus inverter. I assume these have some inefficiency because there is some discussion about heat generated. Is it 90% or more like 80%?

I realize that the induction cooktop will infrequently be turned on high, but shouldn't the batteries and inverter be sized for that?

So there are some real costs directly associated with induction cooking, including the inverter and the additional LFP capacity of about 200ah over the 200-250ah we would need otherwise. Also we woul want at least another 300w of solar in addition to the 300w planned.

What have I got wrong about this picture?

[rgleason]

@Capt Rivet wrote:

For the small boat crowed in the below 38ft range the following receipe works well:

Solartronic 4kw inverter (quite small and oversized so you have enough overhead room), 200AH Winston 1p4S bank with BMS of your choice (recommend Electrodacus or Muller jk bms), 140A balmar small case with wakespeed regulator (this you can run even on a 10hp engine) and bifacial solar panel on your davits, a 365W 1,7m x1m longli should be manageable on every davit even on a 30ft.

Really 4kw inverter? Why?
Wouldnt you need more like 300ah minimum to keep inductive high discharge at below .5?
I like the idea of wakespeed and decent alt.
I will check out 365w lingli.

[Statistical]

Originally Posted by rgleason

Wouldnt you need more like 300ah minimum to keep inductive high discharge at below .5?

The 0.5C reccomendations are for continuous loads. You won't be using cooktop for more than an hour and less at full power. So they have a low duty cycle. Having periodic loads above 0.5C is fine. Most (all?) cells are fine with intermittent loads for at least 1C.

[rgleason]

I guess you are assuming a real BMS with with good batt wiring. not some unknown weak dropin LFP version.

Also 1hr sounds continuous to me.

[Statistical]

Originally Posted by rgleason

I guess you are assuming a real BMS with with good batt wiring. not some unknown weak dropin LFP version.

Also 1hr sounds continuous to me.

The better drop in replacements can do 1C some can even do 1C continuous.

[Adelie]

Originally Posted by rgleason

Thankyou sv/jedi.

Those look good.

1800w/12v=150ah so we need minimum LFP 300ah if discharge is .5, but .3 is better, so that would be have to be LFP= 450ah. We would also likely need a 2kw multiplus inverter. I assume these have some inefficiency because there is some discussion about heat generated. Is it 90% or more like 80%?

I realize that the induction cooktop will infrequently be turned on high, but shouldn't the batteries and inverter be sized for that?

So there are some real costs directly associated with induction cooking, including the inverter and the additional LFP capacity of about 200ah over the 200-250ah we would need otherwise. Also we woul want at least another 300w of solar in addition to the 300w planned.

What have I got wrong about this picture?

I rigorously tested efficiencies. Boiling water on high Induction was 74-75% efficient vs 50% for butane. Microwave was 46%.

I need to check efficiency heating water on medium or low. One of these days.

Other than pre-heating the pan the only thing I can think of that run high power is boiling a large volume of water, to sterilize the water or can something or lots of tatos or pasta.

[mako]

Originally Posted by rgleason

1800w/12v=150ah so we need minimum LFP 300ah if discharge is .5, but .3 is better, so that would be have to be LFP= 450ah. We would also likely need a 2kw multiplus inverter. I assume these have some inefficiency because there is some discussion about heat generated. Is it 90% or more like 80%?

I realize that the induction cooktop will infrequently be turned on high, but shouldn't the batteries and inverter be sized for that?

So there are some real costs directly associated with induction cooking, including the inverter and the additional LFP capacity of about 200ah over the 200-250ah we would need otherwise. Also we woul want at least another 300w of solar in addition to the 300w planned.

What have I got wrong about this picture?

Your picture looks pretty good, but let try some calculations.

The standard American tabletop induction unit is 1800W, like you mentioned. Single or double burner, it's the same at 120VAC. We cook with a single unit at home and except for a few minutes to boil water, we never use the full power mode. It just cooks things too fast and everything burns. Wow, what wonderful technology.

At lower settings the unit operates at a corresponding duty cycle (actually pulse width modulation) to reduce "power."

I haven't measured our stove's power consumption, but you may wish to use say 70% duty cycle as an average. An inverter has a typical efficiency of 88%. This works out to 120ah of electricity if the unit is run for a total of 1 hour daily. Breakfast, lunch, dinner... 1 hour of run time seems realistic.

If you wish to limit to a discharge rate of 0.5, then you'd need a battery pack of 240ah if it were standalone, dedicated to just your cooker.

So although you may wish to upsize your battery capacity by 120ah to include 1 hour per day of cooking, the discharge rate shouldn't be a concern because your bank is already 200-250ah.

At this point you're looking at 2 batteries of 12V-200ah. You may wish to consider upsizing your electrical system to 24V instead of 12V, especially if you see future power-hungry growth, like powering an aircon for a few hours.

[CaptainRivet]

Originally Posted by Grith

It’s a bit more challenging again on a 28 foot trailer sailer but we have managed as our yacht is focussed on long range live aboard style exploration cruising not sailing performance. 1000w of solar panels and 300amp hour in 2 portable drop in lithium power packs and 200amp hour of regular AGM starter and regular yacht system starter and house batteries. 12-24v vitron voltage increaser to eek a bit more charging out of the outboard alternator.
Induction cooked Steak and extras dinner for three on a recent week long cruise with additional friend on board.

with 28ft i would skip a 200AH AGM starter and add a 3rd Lihtium and start from house.
gives you much more flexibility. wire starter directly to house with a breaker and put LVC at 3.0V and you always have enough juice in the bank to start but only miss 5AH.
why such a big starter on a 28ft when you even have outbaords. can you emergency start them manual?

[s/v Jedi]

Originally Posted by rgleason

Thankyou sv/jedi.

Those look good.

1800w/12v=150ah so we need minimum LFP 300ah if discharge is .5, but .3 is better, so that would be have to be LFP= 450ah. We would also likely need a 2kw multiplus inverter. I assume these have some inefficiency because there is some discussion about heat generated. Is it 90% or more like 80%?

I realize that the induction cooktop will infrequently be turned on high, but shouldn't the batteries and inverter be sized for that?

So there are some real costs directly associated with induction cooking, including the inverter and the additional LFP capacity of about 200ah over the 200-250ah we would need otherwise. Also we woul want at least another 300w of solar in addition to the 300w planned.

What have I got wrong about this picture?

You’re not wrong, but things can be made to work for you.

My recommendations for a full electric blue water cruiser incl. watermaker etc. but without generator:

2x Multiplus 3000 inverter/charger
2x 10kWh house battery
2x 1kW solar array

So this is highly shocking for someone standing where you are. But first of, you can use half of that and get by. Everything double is for luxury and redundancy.

We spent a season cruising with only one 10kWh battery and still could run the A/C from it now and then, but we did have 1.75kW solar.

For a 12V battery, you need 800Ah to get into that 10kWh level.

So, does this eliminate the all electric option for you? Unfortunately, yes, it does. But you can still cook some meals on induction, just don’t sell the propane tanks yet!

My recommendation for you is to buy this battery: https://www.litime.com/products/liti...-2944wh-energy
It supports 2.5kW continuous loads and at $700 I don’t think you can do much better.

For inverter/charger I recommend this one: https://shop.pkys.com/multiplus-ii-pmp122305110
At $1,184 it is a good deal, with good 50A contactors in the transfer switch.

So this totals at just under $2k assuming you have the main switch etc. already.

Now to charge it: having a portable generator at hand is great. The Victron can be programmed so that it doesn’t overload the generator, getting the maximum efficiency out of it.
Then solar… yes, as much as you can. You may even eliminate running the generator completely.

If you maintain propane cooking capability, then you could rely on solar more and skip the generator… simply use propane when the battery is too low for induction.

[CaptainRivet]

Originally Posted by mako

Your picture looks pretty good, but let try some calculations.

The standard American tabletop induction unit is 1800W, like you mentioned. Single or double burner, it's the same at 120VAC. We cook with a single unit at home and except for a few minutes to boil water, we never use the full power mode. It just cooks things too fast and everything burns. Wow, what wonderful technology.

At lower settings the unit operates at a corresponding duty cycle (actually pulse width modulation) to reduce "power."

I haven't measured our stove's power consumption, but you may wish to use say 70% duty cycle as an average. An inverter has a typical efficiency of 88%. This works out to 120ah of electricity if the unit is run for a total of 1 hour daily. Breakfast, lunch, dinner... 1 hour of run time seems realistic.

If you wish to limit to a discharge rate of 0.5, then you'd need a battery pack of 240ah if it were standalone, dedicated to just your cooker.

So although you may wish to upsize your battery capacity by 120ah to include 1 hour per day of cooking, the discharge rate shouldn't be a concern because your bank is already 200-250ah.

At this point you're looking at 2 batteries of 12V-200ah. You may wish to consider upsizing your electrical system to 24V instead of 12V, especially if you see future power-hungry growth, like powering an aircon for a few hours.

induction stoves, especially these cheap standard 1800W pulse, means you need full power 1800+approx 300W for bad cos pi =2100W constant inverter. these cheap cooktops have mostly 2 powerlevels between 700-900W and 1800W, the level 1-10 you are choosing is then just different times on/off meane inverter has to deliver the full 2100W. pulse is very bad for the cheap HF inverters as their Mosfets gets compromised switching fast on/off and cos pi phantom load can be higher then 300W means you damage inverter. microwave is the worst for them.
a victron 2kw multi can cope but is frequently in overload.
advise biggest inverter you can afford and fit, most likely the Multi 12/3000 which is in fact a 2400W inverter.

induction cooktops its worth on a boat to look for commercial grade ones for eg catering services, they start at 500Euro.
l had 2 cheap ones before, the 1800W and 2200W Rommelsbacher. cheap 2 burner that had 1st 1000W burner and 2nd 800 or 1200W that pulse, Rommelbacher was better.
now i have commercial grade Bartscher 3 burner 3500W. 1000W/1500W and 2000W burners but electronic limits the power consumption to total 3500W when all 3 are running. cooking on it is night and day difference to cheap ones. mostly i am below 2000W even running all 3 burner as they are so much more efficent.
They are made for rougher environment and cope longterm better with marine environment. their biggest advantage are their commercial grade coil burners which a) distribute/spread the heat across the whole stove, no hot spots in cheap or lower grade pans and you cook 2 levels lower then with cheap ones b) they don't pulse, each level 1-10 is a different power level means eg on my 2000W burner level 1 is 300W, 2 450, 3 600...., burner is on till pan reach set temps then switches off and inverter has to just to deliver this 300W. c)because they don't pulse cos pi loads are much smaller and you get less ripple on the inverter. also cheap hf inverter profit from that and live much longer.

the bartscher IK3342 i have is the budget line and costs around 500Euro which has the commercial grade burners but saved on casing in plastic instead stainless, louder fans and off has still power consumption of 0.5A at 230V as only burners switched off but display and rest gets power. fans are really loud as no priority and constant 0.5A is not acceptable.
plastic case good, no rust stains from salty air. replaced the fans with quiet computerfans (anyone changing an impeller on engine can do that) and installed a toggle switch that cuts total power off, mods where 40Euro in total.

[Pete7]

Folks, I think we have forgotten that both RG and I have smaller yachts, therefore space (and budget) is at a premium. So a pair of expensive Victron blue boxes aren't going to fit easily, if at all. Installing a large LFP bank also tricky. But this needn't be a problem, the various components and budget just needs to match.

So if you need 150A supply at 12v, that would suggest a 120 - 200Ah LFP or splitting it between two 100 - 120Ah LFP batteries or one large LFP. That should be manageable to fit. We draw between 70 - 90A @12v from a single 120Ah LFP plus LA hybrid, for most cooking. BMS is rated to 150A.

The inverter also doesn't need to be a blue box. How about one of these in either 240v or 110v, they are badged under different labels so similar may be available in the US:

https://www.photonicuniverse.com/en/...wer-6000W.html

https://www.photonicuniverse.com/en/...e-control.html

We have one of these new inverters from Sterling or Pro Mariner in the US. Perfectly meet our needs for space, power and budget.

Equally the induction hob needn't be high end, you could buy several cheap ones for the price of an industrial unit and still come out on top. Our single 1500w at 240v now a spare, is very similar to the Nuwave available in the US. As Mako points out, unless you boiling water, you will need to turn them down or you just burn the anything in the pan and it really does heat up quick. Worth looking at the operating instructions to see what power is needed at each setting you are likely to need.

Gimbals and pan holders. A bit of engineering is needed here depending on what you want. We do have several silicone mats from Amazon, a couple of single round ones and a large one nearly the size of a chart. to stop the Remoska sliding. However, we also wanted pan holders so kept back the gas hob pan holders and having made a wooden base used these to mount the double induction hob. Pan holders are also available for a single hob and they just bolt to the work surface.

Staying away from large power items like convection / microwave ovens or large induction hobs means you can have smaller inverters, batteries and need less solar but still achieve a very satisfactory solution. We are delighted with ours.

Pete

[Pete7]

Bit expensive, but an interesting option for a single induction hob, particularly if you keep the gas as standby too. Lots of other types on the market.

https://www.thewetworks.co.uk/produc...-two-pans-only