Induction cooktop?

seascene

Crew Member
I would love to ditch propane in my galley for a single burner induction cooktop. I have 2 x 12V deep cell marine batteries. I doubt that is enough... not my area of experience. Anyone using one of these?
 
Assuming your two 12V batteries coming to 200AH, and assuming you are using a 1500W induction burner.

Assume your inverter is 85% efficient. 1500W / 0.85 = 1764W. I assume you have a 2000W inverter and no other loads on the inverter.

1764W / 12 V = 147 amps of DC 12 V draw. That is a very high draw and you'll need to ensure you have large enough cables so you don't create a fire, and you you need to make sure you don't heat your battery too much on the draw down. Hot batteries die fast, and small cables are a fire hazard.

Now assume you only draw down your battery to 50%. You have 50% of 200AH available. So you have 100AH available before you need to recharge your batteries if you want them to last at all.

100AH / 147A = 0.68 hours of run time. You could run your 1500 induction cooktop for 0.68 hours or 35 minutes before you draw your batteries down to 50% and need to recharge them.

This all assumes you have a large enough inverter, large enough battery cables, a temperature monitor on the batteries, and nothing else using the batteries or the inverter at the time.
 
One thing we forgot to discuss is the discharge rate... If you have 200AH with the two batteries, and you are discharging 147A, the discharge rate is very steep at 147/200 = approx 75%.

Most batteries are designed for a 5% discharge rate (5A on a 100A battery). Golf cart / deep cycle may give you slightly better discharge rates...

Most batteries will tell you if you've got a 6 hour rate (industrial batteries), a 20 hour rate (normal rating), or a 100 hour rate (slightly misleading rating for our purposes). Since you're drawing at 75% of the battery rating, you've got a really aggressive discharge rate and you can expect the battery to get down to 50% significantly faster than 35 minutes. Look at the chart below - shows a 100AH battery giving the full 100AH at 5A (5% of battery rating) 20 hours, but only 81% of the 100AH at 15A (15% of battery rating) 5.6 hours.

Imagine the curve when drawing 75% of the battery rating....

At the end of the day it's hard to beat the convenience and low cost of a propane fuelled cooktop.

1647101103344.png
 
Last edited:
Assuming your two 12V batteries coming to 200AH, and assuming you are using a 1500W induction burner.

Assume your inverter is 85% efficient. 1500W / 0.85 = 1764W. I assume you have a 2000W inverter and no other loads on the inverter.

1764W / 12 V = 147 amps of DC 12 V draw. That is a very high draw and you'll need to ensure you have large enough cables so you don't create a fire, and you you need to make sure you don't heat your battery too much on the draw down. Hot batteries die fast, and small cables are a fire hazard.

Now assume you only draw down your battery to 50%. You have 50% of 200AH available. So you have 100AH available before you need to recharge your batteries if you want them to last at all.

100AH / 147A = 0.68 hours of run time. You could run your 1500 induction cooktop for 0.68 hours or 35 minutes before you draw your batteries down to 50% and need to recharge them.

This all assumes you have a large enough inverter, large enough battery cables, a temperature monitor on the batteries, and nothing else using the batteries or the inverter at the time.
What he said.
 
One thing we forgot to discuss is the discharge rate... If you have 200AH with the two batteries, and you are discharging 147A, the discharge rate is very steep at 147/200 = approx 75%.

Most batteries are designed for a 5% discharge rate (5A on a 100A battery). Golf cart / deep cycle may give you slightly better discharge rates...

Most batteries will tell you if you've got a 6 hour rate (industrial batteries), a 20 hour rate (normal rating), or a 100 hour rate (slightly misleading rating for our purposes). Since you're drawing at 75% of the battery rating, you've got a really aggressive discharge rate and you can expect the battery to get down to 50% significantly faster than 35 minutes. Look at the chart below - shows a 100AH battery giving the full 100AH at 5A (5% of battery rating) 20 hours, but only 81% of the 100AH at 15A (15% of battery rating) 5.6 hours.

Imagine the curve when drawing 75% of the battery rating....

At the end of the day it's hard to beat the convenience and low cost of a propane fuelled cooktop.

View attachment 76348
I'm old and still find electricity magical. It is so versatile in it's capabilities: everything from starting the engine to running very sophisticated electronics. It's almost sinful to use it for something as primitive as heating. Shore power? I guess that's okay, then.
 
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