Inverters and induction cooktop

[Tim22]

I am in the process of updating my electrical and also thinking of adding a Xantrex ProWatt 2000 inverter (1800 watt continuous). Would this be capable of powering an 1800 Watt single induction cooktop?
Thanks
Tim

 

[dlochner]

It is not the inverter that will be the issue, it is the battery bank and the ability to recharge it. 1800 watts is about 150 amps at 12 volts. That's enough to drain 2 Group 27 batteries in an hour.

How large is your battery bank? What kind of batteries? How are they charged?

There is a recent article on Attainable Adventure Cruising on this topic. John Haries is an experienced and very knowledgeable cruiser. If you are considering an induction cooktop, then this article is worth the very modest subscription fee.

 

[Tim22]

Hi Dave
I am upgrading to Lithium so will end up at 200 or 300ah. We mostly use the boat for day sailing and weekending so I’m not to concerned about re-charging as I always return to shore power. also, most of our cooking is on the Barbecue. I have been working on the same small propane bottle for the galley stove for three years which gives you an idea as to how much we use it! The induction cooktop is pretty much an afterthought but it seemed worth investigating as it might let me dump the LPG.

thanks
Tim

 

[alexco38]

Years ago I tried to discourage a club member to rip out the diesel and went with electric.

His argument was " We mostly use the boat for day sailing and weekending so I’m not to concerned about re-charging as I always return to shore power. "

Not my boat anyway, but a few years later he had to scrap it as (1) He couldn't keep it going reliability with positive experience, (2) Couldn't find a buyer even he tried to give it away for free.

Your boat your choice.

 

[dlochner]

Hi Dave
I am upgrading to Lithium so will end up at 200 or 300ah. We mostly use the boat for day sailing and weekending so I’m not to concerned about re-charging as I always return to shore power. also, most of our cooking is on the Barbecue. I have been working on the same small propane bottle for the galley stove for three years which gives you an idea as to how much we use it! The induction cooktop is pretty much an afterthought but it seemed worth investigating as it might let me dump the LPG.

thanks
Tim

200 ah is not very much power, especially if high current device will be used.

I'm curious about your decision to install lithium batteries. That's very expensive option for the kind of sailing you do. The folks who are installing lithium are cruisers who have ample charging capacity with solar and high output alternators and have high current draws for water making, electronics and other things.

Two golf cart batteries will be a lot cheaper and give you over 200 ah of power, with 4 GCs you'll get about 450 ah for about $500 US.

 

[Tim22]

Hi Alexco
No worries. I’m not about to rip out the diesel. This was the year to replace my 8 year old FLA batteries so I decided to upgrade to LiFePO4 for a multitude of reasons. If, as a bi product of this, I can also get rid of the propane I will happily do so. I have never liked having propane on board due to it’s heavier than air property. Hence my interest in induction cooktops.

Tim

 

[Tim22]

Hi Dave

The truth about my decision to go Lithium is that my FLA batteries are due for replacement. Additionally, I am tired of removing heavy FLA batteries every winter and also, I wanted to increase my capacity without increasing the physical footprint. Additionally, I am retired and this seemed like an interesting project. None of these are economic, or probably good reasons but that’s how it came about. I’m not set on the induction cooktop top but, if the bi-product of the upgrade is that a $79.00 cooktop allows us to boil a kettle or fry an egg without using propane then that is a bonus.

Tim

 

[Johnb]

Hi Dave

The truth about my decision to go Lithium is that my FLA batteries are due for replacement. Additionally, I am tired of removing heavy FLA batteries every winter and also, I wanted to increase my capacity without increasing the physical footprint. Additionally, I am retired and this seemed like an interesting project. None of these are economic, or probably good reasons but that’s how it came about. I’m not set on the induction cooktop top but, if the bi-product of the upgrade is that a $79.00 cooktop allows us to boil a kettle or fry an egg without using propane then that is a bonus.

Tim

I get your point. With a truly useable Kilowatt-hour you could

Boil a quart of water 6 to 10 times OR
Run a 400 watt microwave for 30 minutes (using a kilowatt of power) and boil the kettle 3 times OR

many combinations/variations of the above which would provide for a whole lot of food preparation. It would at least reduce other fuel use hugely.

The problem with lead acid batteries is to get any longevity, you need in rated capacity about 3 times what you intend to use, but with lithium can use about all of it.

Using another rule of thumb, that a solar panel can daily produce in energy (watt-hrs) three times its rated power (in watts) it even begins to seem feasible to provide most of ones catering needs from solar power, using it intelligently. Note that this is a feasibility study, not a detail design.

 

[capta]

I can't imagine why anybody would go to electric cooking. Our boat was built that way and we couldn't even make a cup of coffee without turning on the inverter or genset and then waiting for the burner to heat up.
Propane is as good as it gets on a sailboat. Chefs do not cook on electric stoves because the heat is not adjustable enough.

 

[JohnShannon]

I can't imagine why anybody would go to electric cooking. Our boat was built that way and we couldn't even make a cup of coffee without turning on the inverter or genset and then waiting for the burner to heat up.
Propane is as good as it gets on a sailboat. Chefs do not cook on electric stoves because the heat is not adjustable enough.

Induction is way more responsive and adjustable than a conventional resistance type stove. There is essentially zero thermal inertia. It is a super cool technology.

 

[dlochner]

Hi Dave

The truth about my decision to go Lithium is that my FLA batteries are due for replacement. Additionally, I am tired of removing heavy FLA batteries every winter and also, I wanted to increase my capacity without increasing the physical footprint. Additionally, I am retired and this seemed like an interesting project. None of these are economic, or probably good reasons but that’s how it came about. I’m not set on the induction cooktop top but, if the bi-product of the upgrade is that a $79.00 cooktop allows us to boil a kettle or fry an egg without using propane then that is a bonus.

Tim

Tim,

There is no need to remove the batteries each year. If the batteries are fully charged in the fall and disconnected from all loads they will do just fine. In fact they will do better than if they sit in your basement for the winter. The weather here on the south shore of Lake Ontario is not all that different from the weather in Ottawa. I haven't taken a battery home in 20 or more years unless I was replacing it.

One option you might consider if you have the charging capacity is a bank of Firefly batteries. These are AGM batteries with carbon foam instead of the usual stuff AGM batteries are made of. The big advantage to Fireflys is their tolerance of being in a partial state of charge (PSOC). They also recharge faster than other FLA batteries and can be discharged deeper. While expensive, they are much cheaper than lithium. I will probably replace my 4 6v GCs with 2 Group 31 Firefly batteries this spring.

Dave

 

[Benny17441]

I can't imagine why anybody would go to electric cooking. Our boat was built that way and we couldn't even make a cup of coffee without turning on the inverter or genset and then waiting for the burner to heat up.
Propane is as good as it gets on a sailboat. Chefs do not cook on electric stoves because the heat is not adjustable enough.

Not everyone wants to cook to Chef standards on the small galley in a sailboat. Lately we have been cooking full meals at home, freezing and then reheating at the boat. over the years we have gone through alcohol, kerosene, natural gas and propane and they all follow a ritual to get them started. An induction cookstove is no different in that regard but only requires to turn on the inverter. The heat is almost instant and it heats the pot or pan directly instead of a burner coil with the cooking surface remaining cool to the touch. With today's solar panels, high Ah batteries is quite attainable to run an electric cooktop through an inverter. The only peculiarity is that you need pots and pans that are magnetic which rules out aluminum ones. We do keep a propane grill on the stern as that is the only way to cook steaks.

 

[capta]

Induction is way more responsive and adjustable than a conventional resistance type stove. There is essentially zero thermal inertia. It is a super cool technology.

Thanks, I did not know that. It does require special cookware, does it not?

 

[kappykaplan]

It does require special cookware, does it not?

Yes.

 

[JohnShannon]

Not exactly "special" but has to be iron/steel or stainless steel so Al is out glass is out. The "special" cookware is available at Walmart it isn't exclusive in any sense.

 

[Benny17441]

A lot of pots and pans manufacturers are adding a mesh to the bottom making aluminum cookware usable in induction stoves. When purchasing cookware take a magnet with you and if it sticks to the bottom of the cookware you can use it.

 

[JamesG161]

I wonder if the Coil, needed for the Induction, will affect the on board Compasses?

I bet no cooking while underway.
Jim...

 

[JohnShannon]

Well it is a high frequency oscillating field so your compass will wiggle back and forth a million times a second maybe. Do need to pay attention to the DC feed wires to the inverter.

 

[Tim22]

I wonder if the Coil, needed for the Induction, will affect the on board Compasses?

I bet no cooking while underway.
Jim...

nailed it! No cooking while underway.
Tim

 

[JamesG161]

forth a million times a second maybe

Try 24kHz , dog whistle area of frequency.

But the Coil still remains when not cooking.

That size coil might cause a Deviation in your Steering compass and FluxCompass.
Watch out where you store it.
Jim...