[amluto]

Battery powered induction stoves exist, although they are not cheap enough yet. They are, however, truly excellent products. The one from Impulse Labs is not a case of “wow, I can get decent performance without the monster electric hookup it used to require” — it’s “wow, this seems to be the best stove of any sort on the market by a considerable margin, and it’s nifty that it happens to run off an integral battery, too.” If you’re so inclined, you can cook an entire meal or three on it while unplugged.

If someone wants to make them work in rural areas like this, I think the necessary ingredients will be:

1. Cheaper batteries. These are likely coming.

2. More energy. A meal might require 1 kWh or more. (Or less — scrambled eggs won’t require much energy at all.) This is solvable with more panels.

3. Copper. The coil itself is a decent sized hunk of copper. I assume this is part of why cheap little portable induction cooktops still cost $50 or more.

4. Power electronics? I’m not an expert, and I have no idea how much of the cost comes from the power electronics, but integrating the battery and the induction heater seems like it should result in a dramatically simpler system than, say, producing AC from a battery and then converting that AC into a form that will power the coil. The current list price of the Impulse Labs stove includes a hilariously high power output, and a stove targeting rural Africa could be 1/5 as powerful and would still be fantastic.

I wouldn’t be surprised if someone could squeeze the cost of a decent battery powered stove down to $200 in a few years if they had appropriate scale.

[jjcob]

I looked up that Impulse Labs induction hob. Holy Shit, 10kW peak on a single burner is ridiculous!

I already managed to ruin a pan with just 3.7kW (heated it while empty), and I tought that was a lot.

However, I think the cost is probably mostly the battery. Our induction hob (max power per burner 3.7kW / 7.2kW total) costs only 10% of the battery powered stove.

Also, at the low cost, induction is a non-starter. Resistive heating elements are dirt cheap, and the efficiency is not much less than induction. Induction is just way nicer :)

[myrmidon]

Battery power for an oven like this is not necessarily cost-prohibitive; if you want cost effectiveness and long lifetime, LiFePo cells can be had for ~$60/kwh, which would be under <$200 for an ImpulseLabs sized oven.

Absolutely agree on resistive heating for cost effectiveness: Some cheap cells, resistive heating and minimal power electronics would probably be the way to go for the African market.

[hshdhdhehd]

Also https://news.ycombinator.com/item?id=45703666

[gimmeThaBeet]

Dang that 6k is pretty prohibitive not for the overall level, but because it's 4 hobs or nothing. Hardly a "give it a swag" kind of level. I assume they are probably somewhat comparable to the Breville Control Freak, so at a single hob you'd be competing against $1500.

But the battery is a nice philosophy, similar to hybrid/mild electric cars. You don't need all the power forever. You just need more than a 120V circuit can provide.

[jchanimal]

The marginal cost of a hob is likely not the price driver.

[testing22321]

For what it’s worth, cooking a large meal for three (big pot of pasta or rice, brown onions and garlic, brown mince meat, vegetables, simmer sauce) on my induction in my round the world vehicle uses smack on 40Ah of a 12v lithium battery - so about 0.5kwh.

It’s connected with a 3000W inverter.

600W of solar helps a lot.

[jodrellblank]

> so about 0.5kwh

It takes 1.16 Watt-hours to raise a litre of water by a degree. Say 85Wh for 15C room temp to 100C boiling. Assuming your large meal for three is 3 litres, that's 255Wh to get the water boiling. There's energy loss from battery through inverter, through induction. Loss in the pot losing heat to the air. This doesn't count keeping it simmering, or heating the other ingredients.

I don't have any idea if that's very good, to be only twice the theoretical minumum, or quite a room for improvement - have you ever experimented with a 'pot cosy' to insulate the pot and stop radiated heat loss so you can keep it simmering with less power input, or turning the heat off once it's boiling to let pasta or rice cook in the residual heat, or anything?

[ethbr1]

> 'pot cosy' to insulate the pot and stop radiated heat loss

Is this a product that exists?

The closest I could find was ceramic fiber insulation [0], which could presumably be cut to shape and fastened (high temp fastener?) into pot shape.

[0] https://www.amazon.com/s?k=ceramic+fiber+insulation

[jodrellblank]

Yessss, more or less. I learned of the idea from this guy's content[1] who bikepacks ultralight and wants to save camping stove fuel, and he made his own. And from my dad who habitually wraps a thick teatowel around stew pots, on principle (he doesn't measure for a difference in power use. Electric cooktops only, not flame ones). Since it has to be snug on the pot, making one is probably the common way forward.

A few products do exist in that ultralight camping world, the Toaks D95 Pot Pocket[2], the Trangia Pot Cozy[3], Glacier Minimalist "pot with insulating sleeves". In standard size maybe the "So-Vida Sous Vide Insulation Band and Mat for Pots - Protects Your Work Surfaces and Saves You Electricity From Increased Insulation"[5] which is out of stock.

The Wonderbag[6] marketed as for communities in Africa and not available in the USA. From the Wikipedia page on Thermal Cooking[7], in a normal size kitchen people probably go with a vacuum flask cooker, popular in Asia.

[1] https://www.tristanridley.com/post/2019/01/21/diy-pot-cosy-t...

[2] https://www.toaksoutdoor.com/products/coz-m

[3] https://trangia.se/en/shop/pot-cozy/

[4] https://gsioutdoors.com/products/glacier-minimalist

[5] https://www.amazon.com/stores/SO-VIDA/page/BB00BAE8-07C8-4B4...

[6] https://en.wikipedia.org/wiki/Wonderbag

[7] https://en.wikipedia.org/wiki/Thermal_cooking

[testing22321]

No, I never tried.

I have a 200Ah lithium battery, 600W of solar and a dc-dc charger.

To be honest, using up 20% of my battery to cook a large dinner is not a big deal or something I need to improve.