# Induction Cooker Running off Solar DC? (Video Inside)

Solar Expert Posts: 118 ✭✭
I found this on youtube. Someone is running his induction cooker drectly from his Solar pannel array: No inverter or Battery

https://www.youtube.com/watch?v=jPtBYg6N29E Then he has a post in there stating:
"Definitely. Need only battery as storage. No need Inverter. Induction cooker can run on DC supply. Actually, on an Induction cooker, AC mains supply first rectified to be a DC current/voltage before anything else."
Just wondering if anyone knows of an induction cooker that can run off DC (Which I think is what car batteries juice ((Inverter turning it in to AC))) with clamps? I know induction cookers drain like 1300 watts per hour which I think is too much for a car's starter battery. Instead what if it ran an electric car's starter battery? Basically from what I herd the dc to dc converter on the leaf juices up to 1.8k watts to 2.0k to recharge the car's starter battery. So I wonder if it would be possible to "clamp" the induction cooker to the starter battery and have the dc to dc converter recharge the battery as an induction cooker is used?

I tried looking for an induction cooker that can do this, run off a car's starter battery, but I can't find any. I am not sure if they are even designed to run off DC. I guess most are AC for household use (Since DC is in there). Anyway to get around this? I am wondering if I can by pass the whole buying an inverter bit and instead use DC current from the car starter battery. I believe DC can provide TONS of electricity rapidly but over very very short distances. Seems to make sense for an induction cooker which they seem to use a lot of energy. Info on the dc to dc converter of the leaf:
http://insideevs.com/nissan-leaf-dcd...decoded-video/
" This unit takes the 280-400VDC HV battery pack input and converts it to 13-15VDC for the 12V AUX battery charging. "

also info on induction cooker?:
http://www.kitchenbibo.com/how-induc...ooker-works-2/
" First and foremost the AC current is changed over into DC by rectifier. Next the DC current is changed over into ultrasonic high frequency AC current by a high recurrence electric force transformation gadget."

Would it be possible for an Induction cooker to run off a car's starter battery? Not exactly sure what a car battery uses but I believe it is DC. 12v DC? I wonder if it would work just like in the video of the guy running it off directly from solar pannels. If anyone knows of an induction cooker that has 'clamps' to clamp onto a starter battery that would be really helpful

Thank you all!

The induction cooker in the video is using something like 170 VDC to operate (he had 7 panels in series). Many devices (with electronic power supplies) do simply convert the incoming AC to some sort of high voltage DC (~339 volts for a 120/240 VAC mains). Or around 170 volts for 120 VAC mains (sqrt(2)*RMS Sine Wave voltage).

And in some cases (few, some, many?) you can actually feed in the "high voltage" DC directly to the AC input.

However, you cannot feed 12 VDC into the AC mains input of any of these devices and get anything useful out of them.

And a 1,300 Watt unit running on 12 VDC would take (at least):
• 1,300 Watts / 12 VDC = 108 amps @ 12 VDC
Most appliances are designed for around 12 amps @ 120 VAC (US/North American) -- There is no way you can pump ~10x that amount of current into an unmodified common appliance.

And, that is why you will see few (if any) high power 12 VDC appliances. I have seen a few "12 volt microwave), but they tend to be 900 Watt maximum units.

And if you looked for a DC to DC converter that did 12:120 volt step up--You might as well as use an AC Inverter and do it "right" and have 120 VAC available for other appliances/power needs.

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Solar Expert Posts: 3,009 ✭✭✭✭
I would consider such an arrangement to be highly unstable, dare I say dangerous, as available current supplied by the panels will and does jump all over the place as for instance, clouds block and unblock the sun. Likewise the output voltage will be all over the place, depending on the current draw of the load. Very few electrical devices will work with, or tolerate such an erratic power supply.
• Registered Users Posts: 2
Thanks for the link! That's what I've been looking for all along. I have to admit, that guy is even more extreme compared to what I'm planning. At least, I'm trying to run ALL DC system (so no need AC inverter), which runs directly from high DC voltage batteries (maybe 300VDC).

He even bypassed the whole lot (inverter and batteries!). Looking at the guy's other videos (Yohanes Sumaryo), he's also been experimenting with other devices (ironing, hair dryer): https://www.youtube.com/watch?v=_pETq1tnfO4

That gives me more confidence to run lots of other existing AC appliances on DC. Albeit, you really need to know what you're doing. Here's more technical in-depth: http://www.directpowertech.com/docs/Whitepaper_AC_units_on_DC_rev%20A.pdf
• Solar Expert Posts: 9,583 ✭✭✭✭✭
before you can attempt to run an appliance of high voltage DC, you need to verify the internal power supply will not "explode" when connected.   Some stuff is "dead simple", others will silently fail, and others will be explosive
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

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• Registered Users Posts: 39 ✭✭
thinking about it, a simple DC system to boil water or cook could work for the 3rd world. Using wood to make charcoal is wasteful and causes environmental damage. It's also very expensive for the poor. If a cloud comes over, their food cooks a little slower. Keeping the system very simple would help.
• Registered Users Posts: 39 ✭✭
thinking some more, a slow cooker or crock pot would reduce the number of panels, keep the food warm for the night and reduce the need for cooking oil. I have read that charcoal and cooking oil are a significant portion of their budget.
Solar powered ovens can be a good solution (less expensive to build, less easy to damage):

http://www.instructables.com/id/Best-Solar-Oven/?ALLSTEPS

In general, solar thermal collectors are more efficient to collect solar energy for heating.

Although, we had one person here that was pretty happy using solar panels to directly run electric frying pan (you have to match the voltage/current of the panel to the pan).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
• Registered Users Posts: 1
So, it is possible to make an induction cooktop that runs on direct current. I read an academic paper on it, but you might want to follow this link, https://www.instructables.com/id/1000W-Portable-Induction. I am unaware of any commercial product that makes use of this idea. I also do not believe it's as simple as replacing the power supply, although it might be worth a shot, if you are extremely careful (High voltages above 24v can be dangerous). If anyone is aware of a commercially available dc induction cooktop, I would also be interested.
edited January 2020 #10
These days, Induction cooktops for RVs are getting popular... Still need a healthy sized battery bank and AC inverter, but it (seems) to be coming a more mainstream option:

https://blog.goodsam.com/rv-electric-induction-or-propane

Assume something like 350 Watts for 20 minutes (not cooking on high power--Just to make up some numbers):
• 350 Watts * 1/3 hour= 117 WH
• Assuming 12 volt bank: 117 WH * 1/0.85 AC inverter eff * 1/12 volts = 11.5 AH @ 12 volts
Certainly within the realm of something doable with a good size battery bank and solar array. Avoid the whole issue of propane/other fuels.

At this point, would not suggest going high voltage DC or specialized DC powered induction cooker... Even a 1,000 Watt cooktop "burner" is certainly something that will work with a typical AC inverter and >=400 AH @ 12 volts minimum (suggested).

-Bill
Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset