Wow - Induction Cooktop

[Simon.Sails]

Originally Posted by fxykty

Wow, that is a very small battery to handle the current going to the induction hob! We see up to 350A at 12V coming out of our inverter when we run our 2 burner induction hob at higher levels. Even if you had an inverter that can handle the draw (we have a 5KW Quattro), surely you don’t want to go above .5C of your battery capacity if you want your battery to last. With a 200Ahr battery you must be seeing currents of close to 1C, which can’t be healthy.

You're not wrong, but the discharge rates of these lifepo4 batteries are cumulative when wired in parallel. The manufacturer states max discharge rate of 80a for a minute or so, 50a for constant, long run discharge per 100ah battery. That equals 100a/1200W in total for my battery pack. Which equals the max consumption of one burner at max setting, which I never use. 6/10 is hot enough to quickly fry something or make coffee.
So the "bottleneck" is the inverter, which is fine for me really. I don't need the second plate during my coastal hops on a small boat.

Again, it's just a provisional setup until I go fully electric with a more sophisticated setup, but the induction stove combined with some flexible solar panels was a simple, clean and relatively cheap solution for my needs.

[CaptainRivet]

Originally Posted by Simon.Sails

You're not wrong, but the discharge rates of these lifepo4 batteries are cumulative when wired in parallel. The manufacturer states max discharge rate of 80a for a minute or so, 50a for constant, long run discharge per 100ah battery. That equals 100a/1200W in total for my battery pack. Which equals the max consumption of one burner at max setting, which I never use. 6/10 is hot enough to quickly fry something or make coffee.
So the "bottleneck" is the inverter, which is fine for me really. I don't need the second plate during my coastal hops on a small boat.

Again, it's just a provisional setup until I go fully electric with a more sophisticated setup, but the induction stove combined with some flexible solar panels was a simple, clean and relatively cheap solution for my needs.

If you use them at their limits stated by manufacturer the cycle life goes drastically down to 1000cycles or less
And then it depends what manufacturers it is and if their limits are realistic or if they are overrated (most Chinese are) or underrated (like Winston).
A good rule of thumb maximize life do not exceed 0.3C permanent, budget to a good life do not exceed 0.5C permanent and 1C peak.
The higher C you draw the more the production tolerance per cell plays a big role and push the different cells apart what a BMS can only marginally correct over time....
Above 1C permanent only top notch high quality cells can do without drastically shortened life.
LifePo4 with a realistic 1C permanent rating (which 95% are) operated at 2C peak levels regularly have a life span of arround 300-500cycles, do seldom 3C and you are lucky to get 200 cycles.
If your cells have a realistic 2C permanent rating like Winston double the above 0.6C for max life and 1C for budget optimum.

Don't mix this up with the cycle life given at DOD levels. These are 2 different cup of teas.

[kryg]

Where can I find a 240 Volt 2 ring burner induction cook top that is only 460 mm Max long? All I found where 580 mm or longer? Thanks

[CaptainRivet]

Originally Posted by kryg

Where can I find a 240 Volt 2 ring burner induction cook top that is only 460 mm Max long? All I found where 580 mm or longer? Thanks

You won't find 460mm,too small for 2 burners...
Smallest I found is around 51cm
https://www.testbericht.com/produkte...her-ct-3420-in
It fits on top of a gimbaled 3 burner ENO stove, just make a wooden top cover and place it on top. used it on my mono like this and now on my cat. Good thing is when running both burners at the same time it coordinates the bursts to be sequential to save energy and being 2500W not exceeding 10A both full throttle. Both on 7/10 is all you really need then you see 7A means 1500W. Really good one.

[Simon.Sails]

Originally Posted by CaptainRivet

If you use them at their limits stated by manufacturer the cycle life goes drastically down to 1000cycles or less
...

Don't mix this up with the cycle life given at DOD levels. These are 2 different cup of teas.

If you do a quick calculation with my figures you'll see that I should be well below that threshold. In fact I am below 0.5C even while cooking (~700-1000W for about 15 minutes vs 2400Wh battery capacity).

[CaptainRivet]

Originally Posted by Simon.Sails

If you do a quick calculation with my figures you'll see that I should be well below that threshold. In fact I am below 0.5C even while cooking (~700-1000W for about 15 minutes vs 2400Wh battery capacity).

200AH = 200A=1C
1000w@ 240V is around 90A at 12V your inverter draws and that's 0.4C already plus everything else like fridges so 110A is realistic which is 0.55C. All good now
But you wrote your inverter is the bottleneck and you get a bigger one. In fact then your 200AH is the bottleneck, min 400A with budget LifePo4 needed to healthy run a fully electric galley.
The convection and microwave combo needs around 1500W and is the real difference and advantage to a gas oven where everything is black in the back while raw on the front and you cannot adjust any Temps and use a lot gas... And this runs for 20-30m straight putting a 120A load on the house for 30min straight. Plus using a burner from the stove, meat in the oven and making the side dishes like pasta, rice.... So you run 220A permanent for 10-15min plus normal loads so 240-250A.

[Pete7]

Originally Posted by kryg

Where can I find a 240 Volt 2 ring burner induction cook top that is only 460 mm Max long? All I found where 580 mm or longer? Thanks

495mm one here:

https://sterling-power.com/products/induction-hobs-1

[Pete7]

Originally Posted by CaptainRivet

Just get 8 Lishen 272AH cells and a Dali 250A BMS. That's a 544AH Li battery for 1000 Euros.
With this prices forget about lead or AGM

That's the point why:Total time wasted chasing gas bottle refill stations, carrying them around, lugging gas bottles or having them refilled:Zero minutes... none. Go to the Canaries with your european gas bottle, Only in Las Palmas at the gas factory you get them refilled, all other islands zero

Well things didn't quite work out as the Trojan 105s were taller than the saloon seats I planned to install them in, resulting in the idea being scrapped.

Went for a 120Ah drop in LFP paired to a 12v 85Ah trojan FLA. Vey much a
"toe in the water" test to see if it was useful. Set up has been working nicely all summer with 300w of solar to charge it all. Couple of rainy days meant using the DC>DC charger, otherwise solar for power.

Being English we drink tea, lots of it, constantly, so the electric kettle proved itself drawing 4% a time from the LFP. Toaster and single induction hob also tested and fine, but wifey's 1200w hairdryer cuts out on full, so maybe the rating is a bit wonky.

What really impressed is seeing 80A being drawn by the kettle at night, less during the day as solar contributes some. 4 minutes later kettle boils and its back to charging. Its the charging that is also impressive. With a 20A limit from the MPPT we can see 18A going into the LFP right up to 100%. No way could we do that with lead acid and would be down to single figures for hours of charging. Result is the battery is full each day unless its raining.

[CaptainRivet]

Originally Posted by Pete7

495mm one here:

https://sterling-power.com/products/induction-hobs-1

Its 495 deep not long, having that means the buttons are on the side and taking away 5cm of the already limited space of 495-50=45cm
. So you won't be able to put 2 normal pans or a pasta pot. With this limited space you need the side by side one which has the buttons front and leave 500mm space for the pans but theirs is 575mm.

[Pete7]

How big pots and pans are you using? We manage on one of these which is 450mm wide quite happily.

Neptune 4500

I suspect this is why he is asking about hobs that are 460mm wide. Clearly he will have to compromise but that should be doable.

Pete

[noelex 77]

Two single induction hotplates may be an alternative. This provides redundancy and expands the fitting options.

[CaptainRivet]

Originally Posted by Pete7

How big pots and pans are you using? We manage on one of these which is 450mm wide quite happily.

Neptune 4500

I suspect this is why he is asking about hobs that are 460mm wide. Clearly he will have to compromise but that should be doable.

Pete

ENO has the same width but if you put it on top of the gas stove you have an extra 2cm left and right that the gimbal mechanism and room to swing need which makes the 51cm my posted one has and just fits spot on.
Standard pan size is 28cm (that's why the standard width of 2 burner side by side are 56cm) and an 8l Pot 1kg Spagetti fits well has 20cm (already the smallest diameter in that size
and therefor higher) making it 49cm needed.

[CaptainRivet]

Originally Posted by noelex 77

Two single induction hotplates may be an alternative. This provides redundancy and expands the fitting options.

That's much wider, you won't find a proper single one under 28cm width.
2 single ones are easier to store if you use gas and them in parallel, was searching for 2 years and couldn't find anything. But if you do happy to learn and buy them instantly.

[noelex 77]

Originally Posted by CaptainRivet

That's much wider, you won't find a proper single one under 28cm width.
2 single ones are easier to store if you use gas and them in parallel, was searching for 2 years and couldn't find anything. But if you do happy to learn and buy them instantly.

Mine is 27.6cm. I suspect the 4mm less per unit than the minimium you have been able to find will not solve your problem, but my model induction hotplate was not chosen for its minimium width so perhaps there are products narrower if you do a search.

The advantage of two units, as well as the redundancy, is the ability to place the units in seperate locations, which may be a help, or not.

[Auspicious]

Originally Posted by CaptainRivet

Standard pan size is 28cm (that's why the standard width of 2 burner side by side are 56cm) and an 8l Pot 1kg Spagetti fits well has 20cm (already the smallest diameter in that size
and therefor higher) making it 49cm needed.

Jeepers. Standard according to whom? International Association of Tiny Pans? Maybe if you're only feeding one. You'll crowd the pan and run into consistency problems, plus you'll make a mess.

So the induction advocates need special pans AND teeny ones. *sigh*