Pushing the limits of electric cooking

[gtpinhei]

I am also considering ditching the gas stove and oven and mounting an induction cooktop + combi oven on the gimbal.

Saw a bunch of 12v Induction Cooktop on Alibaba. Anyone tried it?

[Pete7]

Originally Posted by gtpinhei

Saw a bunch of 12v Induction Cooktop on Alibaba. Anyone tried it?

Hadn't realised there was such an animal. However, being somewhat risk adverse, I prefer to buy things that others have tested and work well from a company I can track down and easily send back if there is a problem.

I would have thought the big market share is is portable mains electric induction hobs rather than 12v for camping etc.

Pete

[Tupaia]

Originally Posted by gtpinhei

I am also considering ditching the gas stove and oven and mounting an induction cooktop + combi oven on the gimbal.

Saw a bunch of 12v Induction Cooktop on Alibaba. Anyone tried it?

I experimented with a 12v microwave years ago. The 12v cabling to supply it would have been heavier than entire AC installation. Unless the location is right next to the batteries you are likely to run into similar problems with a 12v hob. You still need a substantial amount of watts even with induction technology.

[wholybee]

Originally Posted by koyote

I do see that for the LFPs. the curve is very flat. And I am being told that flatness of curve proves that there is no difference in lifecycle of a battery based on DoD. 40% 60% 92% all same-same. Nothing I've found yet is explaining why flatness of curve proves that.

I'm looking at a pile of sites right now and I'm getting "flat curve means no internal effects because the curve is flat" but not "because we measured" - if the companies are just using legacy setting of 12.8 or 12.7 volts because they don't like change, then they are. That's cool. Guess we'll find out in ten years.

The flat curve doesn't prove it. What proves it is that LFP batteries do not sulfate. Sulfation is the chemical process in a Lead battery that causes the bad effects of deep discharging or only partially charging and not charging to 100%. Those chemical effects just don't exist in LFP.

There are some other chemical processes in LFP, but they are highly influenced by temperature, so a rule about SOC isn't easy to nail down. But, if you keep the batteries in a place comfortable to a person (the cabin and not the engine bay) then those issues are mostly mitigated anyway.

[Jdege]

Originally Posted by Tupaia

I experimented with a 12v microwave years ago. The 12v cabling to supply it would have been heavier than entire AC installation. Unless the location is right next to the batteries you are likely to run into similar problems with a 12v hob. You still need a substantial amount of watts even with induction technology.

Running an inverter uses power, and loses power. That is, simply having an inverter on uses some power, and putting a load on it loses some in the conversion. Modern inverters are very efficient, but they still have losses.

But a microwave? They're not on long enough for it to be much of an issue.

[Pete7]

Originally Posted by Jdege

Running an inverter uses power, and loses power. That is, simply having an inverter on uses some power, and putting a load on it loses some in the conversion. Modern inverters are very efficient, but they still have losses.

But a microwave? They're not on long enough for it to be much of an issue.

Since its only a quick stab on the remote inverter panel to turn on and off, we always turn the main inverter off after use. It's not only the efficiency which for us is 90%, but the quiescent constant draw along with other loads which mount up over time.

[Tupaia]

Originally Posted by Jdege

Running an inverter uses power, and loses power. That is, simply having an inverter on uses some power, and putting a load on it loses some in the conversion. Modern inverters are very efficient, but they still have losses.

But a microwave? They're not on long enough for it to be much of an issue.

It was more to do with the weight size and cost of 4/0 cable. Inverters only really need to stay on when they are in use.

[s/v Jedi]

You need to use AC power for kitchen appliances. Any 12V versions are inferior products for use in cars or camping and have no place in a boat’s galley.

When it comes to high power appliances there’s no choice as 12V simply can’t supply the required power in any practical manner.

For US 120V boats it’s even a consideration to step up to 240V as many appliances like cooktops and ovens require that. A 120V outlet can only supply 1,800W which is a 1-burner cooktop and not even the most powerful one (I have used 3,000W which was great).

[rslifkin]

Originally Posted by s/v Jedi

You need to use AC power for kitchen appliances. Any 12V versions are inferior products for use in cars or camping and have no place in a boat’s galley.

When it comes to high power appliances there’s no choice as 12V simply can’t supply the required power in any practical manner.

For US 120V boats it’s even a consideration to step up to 240V as many appliances like cooktops and ovens require that. A 120V outlet can only supply 1,800W which is a 1-burner cooktop and not even the most powerful one (I have used 3,000W which was great).

Seconded. Higher power 120V appliances are available in some forms though. Some commercial stuff is intended to use 20A circuits instead of 15A (2400W instead of 1800W). And hard-wired devices can have higher amperage as well. My resistive electric stove draws 3300W with all 3 burners on, for example and is hard-wired on a 30A/120V circuit.

That said, 240V appliances do open up more options for high powered stoves and such. On a US boat it's often viable to do a 120/240 split phase setup to allow use of 240V devices, although it does complicate the inverter setup a bit compared to the simplest options available (so there's likely a minimum boat size where it's practical to fit all of the equipment).

[Cheyne]

Our galley is all electric. Due to space on the 380 galley we use a portable induction cooktop that is a single burner. We keep it in storage when not using it to free up counter space. Our oven is a convection that is also portable. When it is hot we use it in the cockpit to keep the heat out of the saloon. We dorm room size microwave. Finally our goto is our Ninja air fryer. We pry use it for well over 80% of our meals. Our galley is 110v, but we have two 20 amp circuts going to it. We started with one circut, but when it came time for breakfast we could make eggs, but not coffee or toast. So the boss requested a second circut.

We have a Quattro 5000 for our inveter charger. The battery bank is 7 x 230 amp hour Big Battery Seal (their marine version of the Owl). We have 2700w of solar. We do not have a built in genset, but from late November to about mid March in Florida and the Bahamas we have Honda 2200 that we use when we don't get enough sun. We are on our 3rd season like this.

Cheyne

[Jdege]

Originally Posted by Pete7

Since its only a quick stab on the remote inverter panel to turn on and off, we always turn the main inverter off after use. It's not only the efficiency which for us is 90%, but the quiescent constant draw along with other loads which mount up over time.

Yep. Even a 3A draw adds up to a lot, when it's running 24x7.

[rslifkin]

For our current setup I specifically selected the inverter with idle draw in mind, as we leave it running 24/7. Our current 2kva Multiplus draws 0.8 amps (12V) at idle with no load on it. A new 3kva Multiplus II is just over 1 amp. For us, ~20 amp-hours per day is worth it for the convenience of always having AC power available and also being able to use AC powered devices for things that need power all the time (instead of having to get a DC equivalent).

[Cheyne]

We turn ours off at night from November to March, but it runs during the day. I turn it off when we go to bed. Not much need at night. Our two freezers and two fridges run on 12v so they are on at night. We can run both our AC units at the same time off our inverter, but that has happened one time in the past 3 years. From mid March until October the solar is more than sufficent for us. Most days we are at 90% by lunch time and finding ways to use power.

Cheyne