So you’re wondering how to power IoT devices?
Let me guess.. you have a cool idea for an electronic maker project but you’re unsure as to how on earth you’re going to give it the “juice” that it needs?
In this post I will cover some of the most common ways that tinkerers like you and I provide power to our home constructed IoT devices.
This guide was created with the beginner in mind but more advanced users may discover some new ideas from people in the tinkering space too.
If you ARE a beginner and unsure about what device to try out as your first project then I have two recommendations for you here:
The Arduino Uno is recommended if you would like to try C programming or the Raspberry Pi if you would like to try Linux/Networking and Python programming.
1. Mains Powered IoT Devices
Mains electricity is one of the most reliable sources of power we can harness.
But by using a mains adapter to power IoT devices we are relying on there being an electricity supply available at all times.
Usually this isn’t a problem as most of our homes have power 99% of the time and provides a stable power source.
But what about that 1% of the time when the power goes out at home?
Sometimes our IoT devices don’t need to have power supplied to them if the rest of the home is without power and sometimes it’s not that important.
However sometimes we have IoT devices that may need a backup power supply to give us that extra insurance that it’s going to stay active during a power outage.
We may even have devices that are designed to activate when the mains power is lost.
- Reliable power source
- Low running costs
- Readily available due to national grid infrastructure
- Provides relatively high power
- Can be produced with low carbon emissions
- Can not supply power to remote locations
- Natural disasters can damage infrastructure
- Often produced with high carbon emissions
- User has no control of supply
2. Power Over Ethernet (PoE)
According to Wikipedia, Ethernet is a family of computer networking technologies such as software protocols and physical hardware equipment.
You may be familiar with Ethernet cables as these are today’s standards for networking computers together via wired means.
Power over Ethernet simply provides power to an Ethernet enabled device as well as providing a network connection.
We can use PoE technology to provide power to capable, low-powered IoT devices although extra PoE hardware may be needed.
If we wanted our IoT device to use Wifi then we could use PoE to a WIFI access point, then connect this router wirelessly to the IoT device for example.
- PoE enabled IoT devices don’t need a dedicated power supply if used in a PoE setup
- Can reduce the need to install power outlets which in turn reduce cost, setup time and provides more flexibility on IoT device location
- Provides a network connection
- PoE equipment may require a higher power source than an initial low-powered IoT device
- Extra hardware may be needed
- Ethernet cable has a length limit
- Limited power supply
3. Diesel/Petroleum Generator
Fossil fuel powered generators come in many different shapes and sizes and can be a great source of power for IoT devices if it fits the application.
One main point to note here is that petroleum generators are generally much cheaper to buy than diesel generators.
Let’s take a look at some advantages and disadvantages of using a generator..
- Provides a relatively large, stable power source
- Semi-portable and versatile
- No outside power infrastructure needed
- Generators require fossil fuels and therefore these can be expensive to run and bad for the environment
- Requires regular maintenance and fuel refills
- Generators produce noise
- Over-kill. Generators provide lots of power but all of this power may not be needed to power small, low-powered IoT devices. However this will depend on the application as a whole and could also be an advantage
- These large units will not provide low-profile or hidden applications
How Long Will A Battery Last?
A battery label usually states how much current it will provide over time before it will require recharging.
Current is measured in amperes and we usually express this as amps for short.
But because 1 amp is usually quite large for small batteries we will see this expressed as milli-amps. (1000 milli-amps is equal to 1 amp) and so a battery will display it’s rating in mAh (milli-amp hour).
If a battery states that it is a 1000 mAh and our IoT device draws 1000 mA then our battery will provide enough energy to last for 1 hour in our circuit.
The amount of current that our devices will draw from it’s power source will depend on the circuit itself.
The more circuitry we have, the more current it will draw from our batteries.
We need to make sure that our circuit has enough power to run otherwise we may see instability such as random reboots, inefficient components such as motors or it will simply not function as intended at all.
Alkaline batteries are likely to be the most common chemical type that is non-rechargeable.
Using non-rechargeable batteries would not be recommended in most IoT projects due to the fact that they will need to be replaced on a regular basis.
Not only is this bad for the environment but it will cost substantially more to sustain your IoT projects.
I would only recommend using non-rechargeable batteries when a rechargeable option is not available.
Using rechargeable batteries in IoT projects would be the most common form of providing power to small, low-powered electronic devices.
Let’s take a look now at what rechargeable battery options are available to us.
Rechargeable batteries are produced in many different chemical types and are not all are created equal as some may be preferred over others.
The following bulleted list of rechargeable battery chemical types are commonly used to power electronic circuits:
Ni-Cd (often pronounced as “Ny-cad”) batteries have been around for a while now and battery technology has moved on since then.
Ni-Cd’s are usually cheap to buy and for some projects they may provide enough stable power for low energy devices.
There’s a well known problem with Ni-Cds called the “memory effect”.
These batteries should not be used unless no other option is available as there are simply better battery technology on the market today.
Nickel-Metal Hydride (NiMH)
Nickel-Metal Hydride batteries took over from where Ni-Cads left off and these are much more preferred over the two battery types.
Although NiMH battery technology is much more preferred over Ni-Cad’s, these have also been around for quite some time now.
It’s not a bad choice of battery for DIY IoT projects but if possible I would recommend the newer Lithium-Ion (which I mention further down this post) battery over NiMH.
Lithium Polymer (LiPo)
LiPo batteries generally provide more power in relation to the battery’s size and weight.
For this reason then LiPo batteries are commonly used in remote-controlled equipment such as drones, quadcopters, cars, planes, boats etc.
However there’s a well-known problem with LiPo batteries.. and it’s not small problem either.
LiPo batteries are well known to bloat up, become chemically unstable and even explode!
Caution must be taken when using LiPo’s and are not recommended for use by beginner’s.
Lithium-Ion batteries are very common to see today as they’re generally used in mobile devices.
They’re small in size, relatively cheap, and provide a stable power source for low-energy devices.
These Li-Ion’s are what you will see being used to power IoT devices most of the time and should usually be your “go-to” battery of choice by default.
Lithium Titanium Oxide/Lithium-Titanate (LTO)
LTO batteries are not something that I commonly see used to power IoT devices in DIY home maker projects.
However, some members of the community have mentioned these batteries and so I will include them here.
An advantage of using LTO batteries over Lithium-Ion batteries is that LTO’s charge quicker.
However these faster charging times come at the cost of having less power than that of a standard Lithium-Ion battery.
5. Battery Charging Methods
Because batteries are the most common form of powering IoT devices we now need to think about how we are going to keep these batteries charged up.
Fortunately we have many options available to us.
Although I can not tell you which is the best option here as you will need to decide for yourself as everyone has different circumstances.
Solar power would not be recommended in low-light conditions for example.
It may be possible to DIRECTLY power IoT devices by using the methods below. That is, without the use of batteries.
However, because most of them don’t provide a stable and constant power source they are generally used to charge batteries which in-turn would power IoT devices.
- Peltier Elements
Did You Know:
Thermoelectric Peltier elements generate power by using a temperature difference between it’s two plates.
These can be seen in many different package types and plates are usually made from a ceramic material.
By providing a heat source to one of the plates, while providing a cooling source at the other end (such as ice) can generate electricity.
Here is a link to a popular peltier element on Amazon and the Youtube video below demonstrates the use of this amazing component to charge a mobile device:
6. Primary And Secondary Sources
Many IoT projects would benefit from having a backup power source if possible to implement in your project.
We could use mains electricity as our primary source for example and have a backup (secondary) power source in the form of batteries.
After all, power is the key to keeping electronics alive and working so having more than one means of supplying this power is usually a good idea.
Usually we would create projects that automatically switch over to the secondary source of power if/when the primary power fails.
However, by charging batteries from renewable resources such as wind, solar or hydro we wouldn’t usually need a secondary power supply.
7. Series And/Or Parallel?
Many of the components that I have mentioned so far in this post can be connected in either a series, parallel, or series/parallel circuit.
Let’s take the batteries as an example:
By connecting batteries in parallel we can add together the milliamp-Hour (mAh) rating which would make the batteries last longer.
If we connect batteries in a series circuit then we would add the voltages of the batteries together.
We can also combine the two methods and create series/parallel circuits which would give us more current and more voltage.
Other components such as solar panels, peltier elements and wind turbines work the same way too.
8. Community Recommended Methods of IoT Power Sources For Remote Projects
Now that I have covered the most common ways to power IoT devices let’s see what others think.
I decided to ask the question on a popular Arduino Facebook group:
“What’s your favorite way to power remote projects?”
And so here I have comprised some of the best responses from the community.
- Battery powered drills
- Battery power bank
- Portable car jump starter
- 18650 Li-Ion batteries
Some community members responded with the following replies:
An 18650 Li Ion battery with a small solar cell does the job for me.
Start with a fully charged battery and some simple deep sleep code and you can run an ESP8266 or ESP32 forever reporting every few minutes
Solar! With LTO batteries if you have time to DIY the charge control, otherwise regular Lithium [Ion]
Portable 20,000mAh Car Jump Starter Vehicle Battery Charger Power Bank
Hopefully by now you have a good understanding of how you can power your DIY IoT maker projects at home.
In most cases there isn’t a “one size fits all” answer to power and you as the maker will need to make a decision on how you will power your own devices.
If you have any alternative ideas other than what I have mentioned here in this post then why not leave a comment below?