Always On Battery Power For IOT

by Guido Bonelli February 23, 2019

IOT is awesome, but powering it... Ugh...

Sure, there are lots of options for powering your IOT project. Like this 3.7v Lithium Ion battery from Adafruit.

But there are just sooooo many weird things that you have to account for especially when it comes to charging them.

For example, battery conditioning.

Don't charge them too fast, don't over charge them...

Oh and especially don't mess with their delicate casing.

If you do any of these things slightly wrong, you'll end up with a really great house burning, skin melting explosive device.

Remember Samsung's Note 7 debacle?

You know, the one with the exploding batteries...

Long story short, they put in a large battery into a Samsung Note 7 and during the manufacturing process, the battery was pinched every so slightly (among other manufacturing issues).

Which in some units pierced the battery, making it a very nice, literal ticking time bomb.

Yeah, that kinds spooks me, especially because one of my latest projects is wooden and requires battery power (more on that later).

You could of course buy a separate battery management board like this from adafruit.

It uses a MCP73833 which is from microchip a great little battery management chip.

This little guy will handle all the scary battery stuff I mentioned however, for me it doesn't work.

That's because (as I mentioned earlier), I want to use this in wooden projects.

Specifically, these tend to get a bit warm or hot depending on how discharged your battery is.

Which for me can be mathematically expressed like this:

Heat + Dry Wood = A flamey, heart palpitating ball of worry

Honestly, it's probably a non issue, but I'd rather a better solution that will prevent the remaining luscious locks on the top of my follically challenged head from falling out.

So...what if you don't want to mess with any of that?

What if you just want something which is already made, takes care of all the safety stuff which lithium batteries require.

Something which has standard inputs/outputs and charges fast and SAFE!

Well, cell phone battery banks fit the bill perfectly for this application.

Well... Kinda...

Gotta rewind for a sec...

A while back I was looking for a way to power a neopixel based project for a lamp I wanted to build.

I didn't want to plug it in as the location I wanted to put her, didn't have a wall outlet near it.

Check out the video below, I call her Teresa.

I just didn't feel like designing my own rechargeable battery pack for the reasons I described above.

I just so happened to have a battery bank for my cell phone and thought

"AHAAA, that's it, this is perfect."

It's rechargeable, robust, self contained in a nice plastic case.

So I started building my project. Only to find out that if my neopixels weren't drawing enough power, the battery would turn off!

Which by the way, took me way to long to figure out why that was happening... Duh...

Makes sense when you think about it, for a cell phone, that's the perfect operation.

But, what engineer uses stuff the way it's supposed to! Pffffffft... lol.

So I search for solutions on how to keep it on during low power situations.

First, I searched for power banks which you could keep on, only to find out at that, that was kinda a weird thing.

The only ones I could find at the time (about 3 years go from the time of this writing), were so expensive it just wasn't worth it.

I could rig up a transistor and just dump some power across a resistor periodically, but I didn't love that idea.

So I kinda just resolved to not really allowing my neopixels to turn off fully when I was using my lamp.

Kinda silly, in my opinion but it worked.

Ok, flash forward just a wee bit

About a year ago, I started getting really interested in "turning wood", more specifically, combining it with acrylic and electronics.

For me, melding electronics with the classic look of wood is the bees knees and I wanted to add some electronics to this master piece you see in the video.

Wait.. what does this have to do with IOT?

Hold on to you soldering irons folks, this is going to be interesting.

After watching Guindillions (that's a 1 with a gabillion, billion 0's after it) of videos on people making all sorts of cool acrylic wooden things, I just couldn't help myself anymore.

I jumped in and started to come up with a concept where I could embed some intelligence into these cool wooden/acrylic masterpieces which again brought up the battery problem.

Here's why...

My current thought for this project is to use an ESP8266 IOT device like this one from Hiletgo.

If you haven't messed with these before, these bad little mama jama's pack a powerful punch and a ton of features.

It has bluetooth and wifi connectivity which makes it great for IOT and are supported by the Arduino IDE!

(Side note.. did you ever wonder where the name Bluetooth came from? Wonder no more, it came from a viking king name Harald Bluetooth. How's that for weird...)

Any who... I want to connect this to my wifi and make it into a type of weather station/lamp.

Something which I can put anywhere but with a long battery life.

So i began to look for a cell phone battery bank for this project and to my delight, I found one which is actually meant for this type of application!

It is a cell phone battery bank but it also doubles as a power bank for your IOT projects as it has an always on feature!

You can get it from amazon here

Awesome right????????? I thought so too so wanted to share with you.

Right now, I've actually built a demo version of just the wood and acrylic meshed together which I turned already. Here is what it currently looks like.

This is the blank I made

And this is after I turned it

Well, that's it, I hope you enjoyed that post!