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I like to go camping and use various gas stoves to do my cooking. I was curious with the current (no pun intended) state of battery technology, how heavy, bulky, and what sort of wiring it would take to cook via battery.

I found an electic skillet designed for RVs online, and its specs are 12v, 12.5amps, 150 watts.

What would be the lightest combination of batteries (motorcycle, car, AAs (NiMH, Lithim, Alkaline)) that would be required to satisfy this, and how should they be wired.

I had read that AA's although they may be rated to ~2000+ mAh, can't consistently put out more than .5 A. So my thoughts were 25 in parallel to get 13 amps, then those 25 in series with another 7 sets of 25 to get up to 12v. In theory that would provide the necessary amps and volts, for as much as 5 hours, but I'm sure there's more to it than that, and I'm not sure if a 12v motorcycle battery would be far smaller and lighter and still satisfy the requirement. And all of my calculations might be way off.

Thanks

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  • \$\begingroup\$ Lithium will be lightest. 150W for 2 hours = 300 Wh, which is roughly 36 pieces of size 18650 Lithium Ion batteries. But don't expect a 150W skillet to do much serious cooking. Basically, cooking with battery power is not practical. Maybe sous vide in an insulated container. \$\endgroup\$
    – mkeith
    Jun 13, 2017 at 0:55
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    \$\begingroup\$ That's an extremely low power skillet, likely usable for barely more than keeping something warm. You're going to have a hard time doing meaningful cooking with a reasonable electric storage battery; the reason that electric vehicles are viable is that combustion powered engines aren't very efficient at turning heat into motion; but when what you want is simply heat, combustion is king. So figure out what sort of gas cylinder/liquid fuel/gelled fuel can is safe for your circumstances. \$\endgroup\$
    – Chris Stratton
    Jun 13, 2017 at 0:58
  • \$\begingroup\$ Here is the actual skillet for reference roadproonthego.com/sp/12volt-portable-frying-pan \$\endgroup\$
    – ChrisYYC
    Jun 13, 2017 at 1:01
  • \$\begingroup\$ I should note, I know it will be impractical. The reason I'm asking other than simple curiosity, is to get the proper calculations down, so that as battery technology increases I can use this as a baseline to see if it has increased to the point where it becomes feasible. \$\endgroup\$
    – ChrisYYC
    Jun 13, 2017 at 1:03

3 Answers 3

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12V x 12.5A is a power of 150 W (Watts). 150W x 2h is an energy of 300 Wh (Watt-hours). These are the key factors for estimating the size of battery needed.

Lithium-ion batteries are about the lightest batteries currently available. A quick Google/Wikipedia search shows that they have a specific energy in the range of 100–265 Wh/kg, and specific power of 250-340 W/kg. Let's use 200Wh/kg and 300 W/kg because they are round numbers.

150W means you'll need at least 0.5kg of 300W/kg batteries to be able to deliver enough power.
300Wh means you'll need at least 1.5kg of 200Wh/kg batteries (to hold enough energy to run for two hours).

We can see that energy is the limiting factor here and you'll need at least 1.5kg of batteries.

You can do similar calculations for other battery types, but I guarantee that this is the lightest you'll get.

An electric stove of this type would be suitable for an RV, because:

  • You don't need to lug the battery around - the RV's engine does that. Because of this, the RV has a bigger, heavier battery.
  • If the battery gets low, you can turn on the engine to convert petrol into electricity. Petrol has a much higher specific energy (over 10000Wh/kg) than any kind of battery.
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    \$\begingroup\$ I'm marking this as the answer, as it most closely answered my question rather than the other ones which gave good information but were more of a 'you can't do it' slant. \$\endgroup\$
    – ChrisYYC
    Jun 22, 2017 at 17:45
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A butane-propane canister contains 12000 Wh per kg of gas.

A Li-Ion battery contains about 100-200 Wh per kg.

As you can see, energy density is merciless. I'm tempted to say "end of story" here, although you should also consider cost, which leans heavily on the gas burner's side.

Also if you want to cook a steak, you need a 2kW burner, which is readily available... bit more complicated on battery power...

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If you are that concerned about weight, on a budget, LiPo is still best. Match the voltage and get extra Ah for safety margin more than 25Ah for >>300 Wh or about 3.6V x 5S8P or 40 cells running PWM at 85%=12/14.2V.

That will cost about 100x more than a propane gas used in a tank. You can get burners to sit right on the tank and it cooks a lot faster.

Conclusion: bad idea.

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