# Heating element for humidifier using a LiPo battery

Thread Starter

#### Mayank_2606

Joined Jun 10, 2020
57
Hey everyone. I am trying to create a battery-powered humidifier. I am planning to use some LiPo batteries for it, with a heating element to produce enough heat to boil the liquid up.

Any help would be appreciated.

EDIT : I wrote humidifier because that was the closest I could find to the thing I am trying to create. My main concern is, If I connect a LI-po or a Li-ion battery with a protection circuit to a metal plate or a cylinder. Will it short the battery out or what could be the worse I would be looking at. Actually I have never worked with Lithium batteries before, hence, all the hesitations accumulating.

Thank you everyone for your responses.

Last edited:

#### KeithWalker

Joined Jul 10, 2017
1,911
You need to do a little feasibility study to see if what you want to do is practical.
What you need to know is how big a battery pack will you need.
How much water do you want to turn into steam, over what period of time? How much energy will that take?
To calculate that you need to include the energy to raise the water to boiling point plus the energy to provide the specific heat to change it into steam. There are examples of how to calculate that on the internet.
If you plan on using an immersion heater, they are quite efficient but you will loose some heat in the system so allow for about 80% efficiency.
Once you know the total energy in Joules, you can convert that into Watt-hours by dividing it by 3600.
Watt-hours will give you the size of battery needed. Watt-hours = Amps x Volts x hours.
Good luck.

#### Yaakov

Joined Jan 27, 2019
3,464
The power requirements for such a device will be very high and your battery life will be very poor.

An average commercial portable humidifer needs 30-50W which means if you are using, say, a 14.4V LiPo pack rated at 2.2AH you would get maybe an hour of operation.

#### djsfantasi

Joined Apr 11, 2010
7,825
I don’t know, but I’d look at an ultrasonic humidifier as well and perform the same feasibility study.

#### wayneh

Joined Sep 9, 2010
17,153
I don’t know, but I’d look at an ultrasonic humidifier as well and perform the same feasibility study.
That's what I was thinking. They atomize the water and throw it out into the room but don't have to directly supply the energy of vaporization. That comes out of the room air.

You might accomplish much the same thing using a high pressure to spray the water out through an aerosol orifice, like the misting stations you see at amusement parks.

#### Yaakov

Joined Jan 27, 2019
3,464
I don’t know, but I’d look at an ultrasonic humidifier as well and perform the same feasibility study.
Just a note:

Ultrasonic humidifiers have some unfortunate side effects including generating a lot of dirt on things if there are minerals in the water and transporting bacteria dangerously if the water is allowed to grow thme.

#### crutschow

Joined Mar 14, 2008
27,696
As noted, boiling water takes a lot of energy, so that's not feasible for any reasonable size battery.

#### ElectricSpidey

Joined Dec 2, 2017
1,796
I have never owned a humidifier that actually boils the water.

#### Yaakov

Joined Jan 27, 2019
3,464
I have never owned a humidifier that actually boils the water.
Evaporating water, not even boiling, is very energy expensive. It takes a lot to change the phase of water. This is the same reason a battery powered dehumidifier is unworkable.

#### Audioguru again

Joined Oct 21, 2019
3,505
I live in Canada where it gets cold in winter which causes low humidity. Many years ago I needed and used a humidifier.
But now the humidity in my home is only slightly less than normal because of no leaks in the weather stripping and for cooking.

#### wayneh

Joined Sep 9, 2010
17,153
I have never owned a humidifier that actually boils the water.
They're more expensive and a pain to maintain but they move a lot more water. The ultrasonic ones are a bit of a joke except for very small rooms.

#### GetDeviceInfo

Joined Jun 7, 2009
1,875
I live in Canada where it gets cold in winter which causes low humidity. Many years ago I needed and used a humidifier.
But now the humidity in my home is only slightly less than normal because of no leaks in the weather stripping and for cooking.
In Alberta here. Anything colder than -15 I turn the humidifier off, otherwise it just pumps water onto the windows to freeze.

#### Tonyr1084

Joined Sep 24, 2015
6,243
Not to overlook the power source and proper voltages, Li-Ion batteries don't like to go below a certain voltage. I know you said LiPo batteries, I'm not familiar with them, but I would think that you'd also need a circuit to cut off the power when the batteries reach a specific low voltage cut-off point. Because I don't know LiPo's I can't say that for sure. Maybe I'm wrong, but I don't think it's a good idea to deplete a battery completely. Of any kind.

#### Tonyr1084

Joined Sep 24, 2015
6,243
Read this on the internet:

1. A fully charged lipo voltage is 4.2V per cell (HV lipo can be charged to 4.35V).

2. A lipo cell battery should never be discharged below 3.0V.

3. The proper lipo storage voltage is 3.8V per cell.

4. A lipo cell nominal voltage is 3.7V.

And since it's on the internet it MUST be true.
Source: https://blog.ampow.com/lipo-voltage-chart/

#### Tonyr1084

Joined Sep 24, 2015
6,243
Thanks bertus that's helpful info. But I didn't see a column for LiPo's. Still, the given nature of the "Lithium" base seems like a pretty good place to start. Hence, the point I was making about using batteries to power a humidifier. Drain the batteries too much and they're done. I accidentally left an LED flashlight powered by a 18650 Li-ion battery on for days. The battery was completely unrecoverable.

#### bertus

Joined Apr 5, 2008
21,524
Hello,

@Tonyr1084 , Read this page:
https://batteryuniversity.com/learn/article/the_li_polymer_battery_substance_or_hype
In there you will find this section:
To make the modern Li-polymer battery conductive at room temperature, gelled electrolyte has been added. Most Li-ion polymer cells today incorporate a micro porous separator with some moisture. Li-polymer can be built on many systems, the likes of Li-cobalt, NMC, Li-phosphate and Li-manganese, and is not considered a unique battery chemistry. The majority of Li-polymer packs are cobalt based; other active material may also be added.

Bertus

#### Audioguru again

Joined Oct 21, 2019
3,505
An older kind of Li-Po (4.2V fully charged) is the same as an older kind of Li-Ion except the Li-PO has a plastic pouch instead of a metal case.
The newer kind of Lithium batteries (some higher and some lower than 4.2V max) have Ferrous or Graphene in them.
My Li-PO batteries are stored at 3.7V - 3.8V all winter long so they last for years.
Some of my Li-Ion 18650 cells are 20 or more years old and are still at 3.7V - 3.8V.

Thread Starter

#### Mayank_2606

Joined Jun 10, 2020
57
You need to do a little feasibility study to see if what you want to do is practical.
What you need to know is how big a battery pack will you need.
How much water do you want to turn into steam, over what period of time? How much energy will that take?
To calculate that you need to include the energy to raise the water to boiling point plus the energy to provide the specific heat to change it into steam. There are examples of how to calculate that on the internet.
If you plan on using an immersion heater, they are quite efficient but you will loose some heat in the system so allow for about 80% efficiency.
Once you know the total energy in Joules, you can convert that into Watt-hours by dividing it by 3600.
Watt-hours will give you the size of battery needed. Watt-hours = Amps x Volts x hours.
Good luck.

Thank you, I will work out the number and look at this again.

Thread Starter

#### Mayank_2606

Joined Jun 10, 2020
57
The power requirements for such a device will be very high and your battery life will be very poor.

An average commercial portable humidifer needs 30-50W which means if you are using, say, a 14.4V LiPo pack rated at 2.2AH you would get maybe an hour of operation.

Actually not exactly humidifier kind of action, What I want to see is if I can use a Li-Po battery to heat up the metal hollow cylinder enough so that it can heat up a really dense wick placed at the center of it. I am new to lithium batteries have only used those 9v cells or some AA or AAA ones. I only know that Li-po and Li-ion do need control or protection circuitry.

The design I saw as a reference, was plugged directly into the wall socket and probably used the AC voltage for it's application. I was wondering if I can use a design as such for battery powered application. So humidifier or a diffuser was the closest I got to something similar.

Thank you so much for the response, it did made somethings clear to me.