Induction Cooking -- Tips?

[CatNewBee]

Originally Posted by a64pilot

I imagine that with 1000 AH of Lithium and 1650W of Solar that yes in fact cooking with electricity wouldn’t be much of a problem.
But that’s not even close to the average cruising boat do you think?

I am not saying, an average cruising boat can have the same setup. We do not have a super yacht, it is a catamaran, 40ft, so we are on the lower end of a blue water cat, the usual size we see is about 43ft...50ft.

It would be also more challenging on a monohull, simply because there is not enough un-shaded area for the solar panels. The battery and the inverter are the key elements that allow this excessive energy usage, the space used and the weight is about the same as 4 x 120Ah equipment gel batteries, but you can go smaller, a dual burner hob for instance and a smaller bank would do the trick too. The admiral uses 3 of the 4 areas while cooking, but it is doable with 2 too. Even if you not have the solar size, you can re- charge by wind energy or by a generator, a 400Ah battery would allow the 2 burner hob or the convection oven. So on a 40ft+ monohull there is no reason why it could not work, besides the investment.

Anyway, if you read the thread, many monohull friends use electric gear for cooking, like contact grills, induction plates, microwaves etc, with FLA batteries a very abusive endeavor, with lithium doable in the long run, LFP have 10 times the life expectancy / cycles, and almost double the usable energy, a 100Ah Gel battery or FLA yelds 50Ah without serious damage and delivers 10..20A continous current, while a LFP delivers safely up to 100A continous and 80Ah. She also weights less than one half of the lead acid battery and charges 10 times faster, charging current on LFP 100A, 1h from empty to full vs. 6...10h at 10A for the FLA until she hits the 100% SOC, due to absorption cycle at low amps.

You are right, the average cruiser is not yet ready for this, but there is a growing community.

[CatNewBee]

Originally Posted by Singularity

An unmentioned safety concern: implanted electrical devices. On the one hand we don't seem to have a problem on land with all the induction cooktops in homes worldwide. Is this because there is no safety concern, or is it because people with implanted devices so far aren't big adopters of the technology? On the other hand, there are medical conditions compatible with sailing off-shore where an implanted device could be in place (some of these conditions being present in young otherwise healthy looking individuals). The best thing a person with a device could do would be to contact the manufacturer of their device. People with such devices should have a card somewhere in their possession with the contact information to ask such questions (no one else can give a competent answer).

My simplistic understanding of the "approved by the FCC" type language simply means that the device doesn't spew electromagnetic radiation that would pose an undo problem to other electronic devices, communications, or typical humans. In other words, the FCC has declared the device not bad enough to outlaw (which is different from giving it a clean bill of health).



I've seen this type of question asked several times but the answers, I think, really need fairly precisely qualifications. For example I can see three different people using three significantly different amounts of energy to cook 4 eggs and potatoes (depending on individual chef style and tastes). Some people seem to simmer their canned soup while others get it up to palatable temperature (if heated at all) and call it a meal...

There are pre-condition you have to be aware off when using induction or microwaves or SSB radios. If you have a cardiac pacemaker, stay away at least 1..2 meter when this devices are on, there is a warning in some manuals. The magnetic field is omnidirectional and decreases in cubic with the distance from the source. You can see this by moving the pot a few inches away from the surface, it won't get warm anymore. But you can use less effective infrared or resistive heat plates instead if you have this issues.

The devices are residential appliances, there is no difference if you use them on board or in the brick home.

[Kenomac]

Originally Posted by Paul L

So how many 12volt amp hours do you use in a half hour cooking session with a pot and pan typically?

I don't know exactly, since I usually do all my cooking with multiple electric appliances while the generator is topping off the batteries. But generally, I see about 60-80aH diminish on the 24 volt bank during a meal prep over a one hour period. Sometimes less but rarely more when I don't run the generator and I'm powered by solar. To cook some eggs or while using just one induction cooktop for a half hour, it doesn't seem to make any difference in being to being able to top off the batteries using only a 450W solar array.

[Singularity]

Originally Posted by Paul L

Well of course the answer is not super accurate. Just like saying I'm using a 2000watt unit but it's duty cycle is low so it doesn't use much. The poster said he's used the cookbook for 7 years on his batteries, so a decent average from measuring actual use ought to be available. Probably a better number than estimating duty cycle.

You are correct on all counts. I meant to refer to the accuracy vs precision problem of data. I've seen people here quote using something like the better part of a kilowatt to prepare one meal where others use a tiny fraction of that, all telling the truth with good data.

I've got 7 years worth of data from my power company comparing my energy use to my neighbors. A person considering moving to my neighborhood on a tight budget should not look at my power bill, unless they too tolerate a too hot or too cold house, and are not offended by a frequent "pasteurization is all that matters" style of cooking.

<---without popping the corn.

[alansmith]

Pelagic, good question about why buy used.

Many steel pots and pans retain their beauty for many decades. My father’s pots and pans are still attractive from the 70’s. They are neither stained or unattractive. I’ve seen pots and pans st Goodwill type centers in the same serviceability for 5 dollars. You don’t need to pay 100 bucks for the same item. It’s a matter of choice, da?

It also leads one to the question of personality quirks. When I tore apart my fathers bathroom after he passed I saved a lot of the green tile from his shower. I spent many hours knocking off the thinset and cleaning them up to new condition.
Then I used them in our studio apartment bathroom. I tore apart the closets in two bedrooms and salvaged the cedar. I converted two closets into one large one and reused the cedar. I am the type of personality that recycles. I am frugal by nature. That’s is why guys like me buy 8 dollar sleeping bags at Goodwill and have them cleaned instead of spending 100 plus at REI. Besides... I got a pair of used gym socks that the last inhabitant left in the foot of the bag. I recycled those for polishing wheels.

[sparrowhawk1]

Sounds like an opening for a drift. I have stainless steel thermos coffee mugs that I love but I could never get them totally clean until one night I made Bloody Marys and of course fell asleep without washing the mugs and lo and behold the next day when I scrubbed out the dried tomato juice they were shiny clean.

[Symphony]

Originally Posted by Kenomac

We've never used gas aboard the 53 we purchased 7 years ago, we immediately went with the NuWave cooktops at the time and I began a CF thread on the subject to share our experience. We also use two induction cooktops purchased at Walmart for $80 each on the 62 in addition to gas and microwave.

It seems funny to me to see people just becoming introduced to such a good idea so many years later, but I guess you have to get started sometime. We also needed to rewire the galley into individual circuits because of electric cooking, making each individual socket independent, and we usually need to run the generator instead of going through the inverter when using multiple cooking devices, like when we operate the microwave and two induction units at the same time. Using only one appliance at a time can be done via the 2500W inverter.

thanks for your experience, Ken. Always interesting and helpful.


PS - do you still have two boats?

[Paul L]

Originally Posted by Kenomac

I don't know exactly, since I usually do all my cooking with multiple electric appliances while the generator is topping off the batteries. But generally, I see about 60-80aH diminish on the 24 volt bank during a meal prep over a one hour period. Sometimes less but rarely more when I don't run the generator and I'm powered by solar. To cook some eggs or while using just one induction cooktop for a half hour, it doesn't seem to make any difference in being to being able to top off the batteries using only a 450W solar array.

That sounds pretty high, certainly beyond a non-generator boat. That's 2,000watts or about 160ah on 12 volt system. That would double the electric budget for a lot of small 12v boats. Of course as long as you run your genset for each meal it's a wash with your batteries higher charge after you're done.
I'm not ready to dump the LPG setup on my boat. At this point I figure it and it's operators are pretty safe. Plus it is really efficient the way we use it with one of our two tanks lasting probably 10 weeks. But it seems like an induction burner would be a nice backup and occasional use item that wouldn't take up a lot of space. Haven't looked at these but I assume you can get a small, single burner induction countertop unit that is 120v AC? Is you setup gimballed?

[a64pilot]

Ken gave us the answer.
He uses 60 to 80 AH on a 24V system per meal preparation.
Let’s use the middle number, that is 70AH, or 140 AH on a 12V boat.

I consider my boat to be an electrically intensive boat, we have a BD80 14 cuft spillover fridge, and also have an Engle running as a dedicated freezer, charge the phone, a couple of IPads, Kindles, leave the NMEA backbone powered, watch an hour or two of TV every night etc.
From beginning of one Solar day to the next, or about 17 hours I think, we use about 150 AH.
If we cooked a meal, I assume a good meal as it takes an hour to prepare, not just hating a can of soup, we would essentially double our electrical consumption and would have to run the generator to do it.
So what we would be doing with only our 1KW of Solar and lead acid batteries is swapping propane for gasoline or Diesel and the associated maintenance and costs of running a generator.

Now if we had way more than a Kilowatt of Solar and Lithium batteries, then you can likely live with the consumption.

However most do their heavy cooking for Supper, which is often late in the day, which isn’t when you want to run a generator to top up batteries, you want to do that as early in the morning as you can.

[Pelagic]

Originally Posted by a64pilot

...So what we would be doing with only our 1KW of Solar and lead acid batteries is swapping propane for gasoline or Diesel and the associated maintenance and costs of running a generator.

You're right, going electric does mean that you need to supplement your storage batteries with Generator.

I think from a practical point of view, you need a boat large enough for a diesel gen so you are only carrying one fuel. Then trading propane for diesel is to me well worth it for the safety and benefits of induction.

Then, turning on the generator for an hour or so at cooking meal times is not a big deal
Charge Batteries/ make water/ freeze holding plates/ heat water costs about 2 liters of diesel per hour for my 10kw Generator.

Rainy Season, that is a given and if you have some solar, you probably only need the Gen for 2 out of the 3 meals a day.

I like to compare that fuel consumption with car commuting costs or marina charges to keep it in perspective

[cj88]

Originally Posted by a64pilot

.

However most do their heavy cooking for Supper, which is often late in the day, which isn’t when you want to run a generator to top up batteries, you want to do that as early in the morning as you can.

Or use the induction cooktop for a short period earlier in the day in conjunction with a thermal cooker.

[CatNewBee]

Originally Posted by cj88

Or use the induction cooktop for a short period earlier in the day in conjunction with a thermal cooker.

What is the point when to use the cooktop? Batteries are meant to store Energy and release it on demand, no problem when they recharge the next morning, you can cook on moonshine in the middle of the night if you like.

[CatNewBee]

This is my consumption last year in August while sailing the Med for reference, we used the solar for everithing, cooking, hot water, A/C in the evening if necessary, watermaker, 2 fridges, 1 freezer, ice cube machine, navigation, radar, electric winches all of 1650Wp Solar. You see when the battery stays below full the day and when she was full and goes to float, so solar only feeds directly the loads. We used to turn on the waterheater in the morning to drain the battery more and allow full usage of solar if possible when it was a sunny day, otherwise we used the remained warm water in the tank. Beside this, no measures to save power. Mean energy consumption about 3.5kWh per day or 270Ah at 12V, sometimes more, sometimes less.

The reading is from the Victron MPPT 150/100 Smart solar controller. Since it was the only source, it reflects the consumption.

Our morning routine involves baking frozen baguettes for 12 minutes at 220°C in the oven, running our espresso machine for coffee and capuccino too, what also consumes some Ah, we used to cook one meal in the afternoon on 3 hobs, fish or meat in a pan, potatoes or rice or pasta in a pot wit water and some veggies in an extra pan as side dish, like fried zucchini, paprika, aubergines... whatever. So serous cooking, not just warming up canned food.

The high consumption mid of August results in using one A/C unit in the evening for about 1..2h to cool down the owners hull and have a good sleep.

[Singularity]

Originally Posted by a64pilot

However most do their heavy cooking for Supper, which is often late in the day, which isn’t when you want to run a generator to top up batteries, you want to do that as early in the morning as you can.

TL;DR: learning to eat old fashioned with supper routinely being a light meal, maybe even going back to routinely eating soup for the evening meal, may reduce wear and tear on both the boat's energy system and the energy system of the boat's occupants.

Historically in seemingly all cultures the evening meal was soup, largely remnants of the noon meal (the noon meal historically being called dinner in the US until ~75 years ago).

Eating a feast at night used to be limited to special events (wedding, death, etc) unless you were a king or something.

From a health standpoint it makes no sense to routinely eat a large meal in the evening time; this practice is arguably a modern invention of over-commercialization and/or simply living in an era of surplus.

Eating a large meal in the evening time does at least two things:
1) typically being heavy on the fats/oils, the meal stays longer in the upper GI tract, invariably contributing to reflux symptoms (including pulmonary reactivity to those so afflicted) once the person lays down to sleep
2) ensures that the person has absorbable calories 24/7 in the alimentary canal somewhere such that energy stores in the liver are rarely tapped, thus likely (from a logical standpoint) contributing to insulin resistance/fatty liver type issues while generally inhibiting ketogenic weight loss.

It's true that the batteries can be sized to cook large evening meals, but simply not cooking large meals in the evening makes more sense.

[CatNewBee]

whatever... Usually we enjoy the day and eat when hungry. Often it happens in the afternoon, because its just too hot to cook at noon.