Why are there no heaters powered by lithium-ion batteries?

Question

Electronics

I have a simple question. Here we have heated clothing that runs on batteries (often 12V), works well, the topic has been mastered, incl. manufacturers of clothing for builders and engineers.

But what is not, and what I cannot find point-blank, is portable battery heaters. So that from ordinary batteries (for example 18650) it is easy to create heat and dissipate it in all directions.

The question is inspired by all sorts of tourist discussions. Gas and gasoline heaters of this type exist, but electric ones - during the day with fire. Yes, it is clear that the energy intensity and efficiency are not the same as those of gasoline, but anyway, why does no one do this?

Answer 1

I will clarify, it is more correct to talk about energy intensity.
Heating is determined by power, this is the product of current and voltage.
The amount of stored energy in tanks, per unit of weight, alas, is not large .....
And clothes - yes, they are locally made, where there are no large losses, heat does not escape to the sides. And do not go far from charging ....
And about the efficiency, it is very high for electric heaters, in fact, all the energy goes into heat.
Yes, and what an efficiency is quite large, if we understand the ratio of stored energy to that which was spent on charging.

Answer 2

And so, here we have a small 150W heater https://aliexpress.ru/item/1005001640986527.html
In one LIIon 18650, about 3Ah
i.e.
3.7 * 3 = 11.1W
This means that such a battery will work for an hour if 1С
150 / 11.1 = 13.5 is taken from it And so, in order for a small stove to give us heat for an hour, you
need about 14 lithium 18650
batteries are degrading, there won't even be an hour

Answer 3

battery power is weak.
Therefore, sufficient heating for a long time can only be provided by a large battery, which you cannot drag on yourself. For example Tesla car battery

Answer 4

there are many, you just need to ask the search engine the query "heated clothing"
here is the first link
https://zen.yandex.ru/media/hyperu/kurtki-s-podogr... I
completely agree with Vladimir - the energy efficiency of electric energy sources is incredibly small compared to a chemical source (fuel oxidation)

Answer 5

What's the problem with taking nichrome and winding how and how much you need and where you need it? You can calculate for 12V, and at least 3V, but this will only upset you - the battery will be discharged before something significant heats up. If only some thermally insulated container is heated autonomously in order to compensate for heat leakage, then yes, it makes sense in some applications.

Answer 6

To heat the human body under winter clothes, in fact, you need very little power, there is literally 10-15 watts and you already have a pleasant warmth on your back, the battery in your pocket is enough to warm up for a couple of hours.
And to heat the air, you need a hundred times more power.