Can 2 batteriers/inverter run 2 burner induction stovetop...

J

johnf

Member
Have been reading some of the posts about an inverter including the makes/models that others recommend with keen interest...thank you for the information.

Can you share any thoughts/recommendations about using a high quality true sine wave inverter with 2 batteries to run a 2 burner induction stove top and a Webasto (or Wallas/Espar) heater at the same time.

I do have a Honda 2000 generator that I can use to bring the charge back up on the batteries.

Believe the boat has a voltage shut off device (will have to get a picture/make/model) that might protect me drawing them down too far.

Don't want propane...thinking about a dedicated diesel cooktop that vents overboard (as does the Webasto) but I'm intrigued by the induction idea but suspect it will draw too much/too quick.

Thanks in advance for sharing any knowledge/ideas on this.

Crazy John Frazey
 
It seems like a really great way to go if you had a dedicated genset going since you could skip the batteries. With group 24 batteries? I don't think you'd ever be really happy as 30 or so amps at 120V (I know all the way up), is a huge amount to change from 12V DC. It takes about 11 amps of 12V current to make 1 amp of 120V AC current as inverters are not 100% efficient. With that said, you are going to need batteries from a commercial boat/truck to make this happen. And even then, it isn't really even realistic as I see it as you are not going to be cooking very long before you have very dead batteries that will take hours to recharge. The diesel stoves are great little units for cooking and heating.
 
Hi!

(Using the two burner electric example cited.......)

The 30 amps at 120 Volts equals 300 amps (10:1) (or 330 amps at 11:1) from your 12 volt batteries. This is similar to an electric starter motor draw! (Or a windlass!)

Not only that, but 30 amps x 120 volts = 3600 watts, so you'll need a 4000-5000 or so Watt inverter.

Two group 27 batteries with 110 amp-hrs = 220 amp-hrs, but limiting the total draw to 50% goes back to 110 amp-hrs available, and at 330 amps draw, would get you 110 amp-hrs divided by 330 amps draw, or 20 minutes to cook.

Then recharging the 110 amp-hour debt would take 11 hours at 10 amps recharge rate, or 3-2/3rds hours at 30 amps.

Looks like a decent set up for shore power, but maybe not for battery/inverter/ generator operation afloat.

Joe. :teeth :thup
 
Thanks guys...really appreciate the information/guidance!!!

Think I'll quit daydreaming and come back to reality and look at diesel cooktops that vent overboard.

Excited lately because I just finished a wood project (check out my pics) so I'm now focusing on heat/cooking.

Electricity is probably not my strong suit.

Back to researching and then hopefully some boating tomorrow.

John
 
Looking at the specs I see that this is a 240 volt unit, not 120. You are going to get more complicated with a 240 volt inverter. There are a number of 120 volt cook tops, which run about 1500 watts. You can get by with a 2800 watt Magnum inverter--since quality sine wave inverters have a significant reserve, even for a number of minutes). You don't have to run an induction burner at full capacity--but you are going to have to have a 30 amp circuit.

I have run a New Wave, single induction burner, and done some experimenting with it. I can run it off my Honda EU 1000i at 680 watts, and this is a temp, which will cook eggs, boil water etc. (You don't have to use the full output of an induction burner--in fact we rarely do.) You want an induction cooktop which has a number of various settings. So far our NuWave has worked well for us. (Purchased at Wally World, not TV!)

I have a friend who has a bus conversion, and runs 6 golf carts, with a 2500 watt inverter, and runs a two burner convection stove off that. It would run off 4 golf carts almost as well. The 4 golf carts are about the same as two AGM 31 batteries.

One of the advantages of the convection burner, is that you can adjust the power, and that you can do cooking in much less time, with very precise heat control.

Lets say that you have two AGM group 31 batteries, which have 120 amp hour capacity each, with usable capacity of 120 amps hours usable from two batteries. (do not discharge more than 50%). Or better yet, a lithium ion battery, where you have a120 amp capacity, and that is basically 100% usable. Use the induction burner at 700 watts, or about 77 amps an hour 12 volts--but you only need it for 10 minutes for cooking dinner. So divide by 6, and you have only used approximately 13 amps. Two burners would be 26 amps in that 10 minutes. With a 60 amp charger (which two of the AGM 31's would take), you can recharge in less than an hour. (I am making several leaps here, including that you would only run both burners at 700 watts each.)

To do this is not going to be cheap. You are going to pay $320 for the two AGM group 31 (Sam's Club), the Magnum 2800 watt inverter with 125 amp charger (I am most familiar with this unit, and it is of the highest quality) The charger can be adjusted with the remote to any charge rate you want: $2200 for inverter and remote. Plus cables: about $50, and a Victron BVM 700 for $160. The $350 for two single induction cook tops. Total: A little over $3000!

Alternative:Buy one of the NuWave induction table top burners (stowe over the water tank under the port side settee, with lots of room to spare). Use this when necessary--one burner cooking is fairly easy. You can run this off the Honda EU 2000 you already own--cost: About $100! We have used one with our Wallas, or one with a propane burner (I also have an aversion to propane on the C Dory 22, although I have had full propane installations on larger boats. We do carry the single "coleman" type of propane tanks in the vented Lazeratte).
 
Thanks Bob...figure a Webasto heater and the Webasto X100 cooktop (both run off diesel) will be a pretty penny. Don't really want to run the generator if I don't have too.

Do know we enjoyed the Wallas (both cooktop and blower lid) on our 22 but agree with someone that said it is good at both but not great at either.

Thinking I want to run a dedicated heater (vents/ducting) on our 23 and then when needed use something for cooking and would like 2 burners.

Having a tough time deciding on what we want in there....

John
 
Hello, We removed the alcohol stove and filled in the hole and resurfaced the counter top. We use a portable single burner induction top which lives under the rear dinette seat on top of the water heater much like Dr. Bob. We learned years ago the you have to recharge batteries each day (when not running the engine to travel) so we run the Honda 2000 at meal time whether using the microwave or the induction. The gen makes everything easy. 8 meals out of 10 we only need the microwave anyway. We also love the "Giant" counter space for many reasons besides cooking. added pics to the album. We now have built in the microwave below the counter. Don't forget to have a magnetic pan required for induction cooking.
 
Thanks....looked at your pics and liked the new countertop. Bet all the space is great on the counter...in our 23 it seems almost like we don't have as much space as our 22.

Like the idea of a microwave under counter...cool idea.
 
Hi John, To put the microwave under the right side of the counter we built 3 shelves and the oven sits on the top one while the lower 2 each have a covered plastic tote for kitchen stuff. We removed the 115v outlet box from it's useless position behind the driver's seat and rerouted the wire to an outlet box under the counter for the microwave and another one above the counter in the rear right corner with the head wall where we plug in the induction burner. I'm sorry I don't have any pics of this part of the project. It all works very well. Have fun, Bob
 
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