# 18650 and LiPo battery (from phones and laptops) Uses



## Topher_osAUrus (Feb 25, 2018)

I mentioned in the WTB thread I made recently, that they were for a project. I have had a few people message me with offers (thank you all), and a couple that were curious about my plans for them. So I figure I could post a wee bit about what (little bit) I know. As well as what I am going to be using them for, and a couple other things (such as how I charge them, and get the useful energy back out, and into what I want running).

First, I should probably say this-
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This post, and anything I say in any of my videos is provided "as is" given, without warranty of any kind, expressed or implied. Just because this is how it works for me, and I havent blown up or burned my house down yet, does not mean that you wont accidentally short something and end up killing your goldfish in a fire.... I, personally, nor is the forum responsible for your actions. Please do study before jumping in... electronics should be treated with as much respect as the chemicals in refining. If I am WAY off base, and you have CITED FACTS, please share! I LOVE to learn!
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*The theory*

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Lithium batteries are everywhere nowadays. They have slowly but surely taken over the rechargeable market, killing NiCad dead. There is an endless supply of them in old laptop batteries amongst many many other things. Like phones, tablets...well, anything that you plug in and charge, then take off the mains voltage and it still magically runs... (Please do add any sources that you have found!).

Generally, they are 3.6V-3.7V nominally(except for LiFe, which is 3.2V nominal), Lithium ion and/or LiPo (those 2 are synonymous, if you believe Dave from EEVBlog) get charged up to 4.2V (this number is quite important) 
What is more important, is their chemistry. For the most part, they are simply aluminum (aluminium) and copper electrodes with a graphite electrolyte, with very few lithium ions acting as the charge carrier. (Some lithium batteries actually DO have sheets of lithium as the electrode, as far as I know, NO 18650 cells or LiPo cells do
[this was learned on the interweb, to be taken with 1 grain of salt]

LiPo packs


LiPo packs (see attached) are generally found in the compact pocket size tech that we carry with us daily. Our phones tend to have a ruggedized pack, while tablet's are simply packed in their aluminized casing and sealed tight. This makes LiPo packs great for energy density vs. volume, but also leaves them quite vulnerable to puncture when being used in projects. So, obviously, great care must be taken when using LiPo batteries to power other stuff. (puncture it and you are going to have a bad, bad time)

18650 cells


18650 cells (there are other numerations, but these are most abundant), are basically identical to LiPo, except they are housed in a cylindrical shell, which makes them a bit more resilient and also a bit more abundant. These are what I will be focusing my main project on, while I will also be using Lithium Polymer packs for lighting.

HOW they are charged, is pretty critical (allegedly! **1)
I like to use my lab bench power supply to charge them, it has CC/CV as well a over current and over voltage protection, and it allows me to view what the current is dropping down to during the charge. 
If they drop below during storage or active discharge 2.5V, they should be charged with a LOW constant current, until they reach around 2.5-2.7V, then, they should be bumped up to 4.2V and charged with constant voltage, (I say allegedly, because the datasheet citation at the bottom of this post, shows some incredible info for what 18650's can withstand) Once the current starts falling to below 10-20 milliamp, I usually take the power off them. 

There are several kinds of protection circuit boards for lithium batteries, in fact, most LiPo batteries have them tied in before their power and ground leads. Some 18650's also have a protection circuit built on top the + terminal (which makes them hard to fit into "18650" slots). Should you have batteries that don't have a protection circuit, they are readily available online on eBay for pennies on the dollar, and they make life quite easy, by simply plugging in a usb 
("what!?! A USB is 5v" you say?, well, thats where the protection board comes in, which has a buck converter chip on board, to knock down the power to a constant voltage and varied current)

A couple charging boards I have


The charging boards are the small discreet pcb's bottom middle, the left side is a couple boost converters (for taking the 4.2v up to 35, or 120v in the case of the huge black one), the top middle is a boost/buck converter (for dropping power down to a stable voltage, say from 12.x volts from 3, 18650 in series, down to 5v for an Arduino microcontroller) and the two items on the right are two charge capacity checkers/tester units.

HOW they are discharged is not really as critical, so long as their voltage doesn't sink too far below 2.7V, if it does, some of the protection circuits used in charging them (with a usb cable) believe the battery has gone bad and wont charge it up. Depending on the application the battery is used in.
They can release a pretty impressive amount of energy at once, some can drop 4 amps or more for an extended time (until they run out of juice anyways)

POWER BANKS


Power Banks are probably the best way to use 18650 cells, they come in all shapes and sizes, but you can get "DIY" banks from China, for literally a dollar. They come with their own protection circuit in them, and allow you to power anything you want. Literally. The blue and pink one are just standard ones, blue has 2 cells in parallel (adds the amp hours, compared to "in series" which adds the voltage), the pink has 5 all in parallel.
The thin black one is LiPo driven, with a 2.1 and 1 amp output, nothing special..but... The BIG black one is pretty nifty, it is a "laptop charger" and has selectable voltage from 3.6, 5, 9, 12, 15, 19, and 21 and can output 75W at once! beastly... beastly enough to run a power wheel :twisted: 

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The Projects
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Firstly, is one that deals zero with refining. 
I was given the idea by Jimdoc to use lithium on my sons powerwheels.. Done! Well, not "done" but, I will be soon enough. 

I have been getting supplies over the winter (slowly but surely from China), that are going to allow me to run 18650 cells in his dumptruck and use a boost converter to make his truck have some more pep. Along with a pulse width modulation module in series, so I can easily tune it down without having to dig in the battery compartment. I am going to also be running headlights, blinkers, and a stereo in there for him as well. After that, if it goes well (read 'easy'), then his power wheel tractor is next.

After the boys are satisfied with their toys, then it will be time for me to finally making my new fume hood. Since my last one kind of killed itself when moving (it wanted to taste the highway at 65mph), I am going to build a new one. This one will be better, faster, stronger, and most importantly -part of the 21st century-

I want my fume hood to be intuitive, so I am using Arduino to help it, help me.
The first stage of which I will be simply using Arduino to run a relay that runs the fan. A ultrasonic distance sensor will be telling it to kick on or off, depending on if there is anything in the hood on the hotplate, or if there is a bucket in there, or whatever. Part one will also have lighting. I am going to have a PIR (passive infrared sensor) pick up when I am walking up to the hood, and turn on the LED lights. An LDR (light dependant resistor) will determine if it is 1, 2, 3,or 4 rows of LED's that kick on (depending on how much ambient daylight is in the lab)

Having a microcontroller on my hood gives endless possibilities. Stage 2 I will have the hot plate hooked up so it can be controlled from my phone. Stage 2 will have me adding local phone access, via RF communication and then eventually bluetooth. In the end, by projects end (maybe a year or 2 down the line) I will have the hood hooked up in the IoT (internet of things) world via the Wemos D1. When I have it on WiFi, I can then have a camera module on it, sending me pictures via text or email, showing me what the reaction looks like. If it needs some more nitric. I will hit a button on my webserver, which will activate a peristaltic pump and adds a small dose of nitric to the reaction vessel. 

There are many many more ideas that I have for making my hood and refining lab a more modern version, but I am only 1 man, and I am taking my time and learning to do things good and proper so I can say it was all done by me and me alone. I don't worry about the fumes getting to the controller, because I have waterproof project boxes that I am going to be using, so any stray fumes that make it out of the hood, will have no effect on it.

Anyways, that is my outline.. Learning Arduino programming has been the primary focus of my studying the past few months. By spring's end, I will have (at the very very least) stage 1 and probably 2 done. I was thinking of documenting it in depth on here, but I figure most probably don't care, and like the KISS methodology better. If that be the case, then this can die out here.
But, I will take at least a few videos and add links to them for anyone who does want to see them.


reference-
1)Samsung 18650 datasheet
http://www.meircell.co.il/files/Samsung%20ICR18650-22E.pdf

(Allegedly!, refers to link above... they test charging these these at 12v over 2a for 12 hours -no fire! nothin'! , in fact, its very interesting reading what torture they put these batteries through...)

2) segway lithium battery datasheet
http://www.segway.com/media/1595/li-ion_important_information.pdf

3)"How to identify 18650 cells"
https://xaeus.wordpress.com/2016/09/08/how-to-identify-18650-cell-capacity/

WAY too long; didnt read?
Want to watch? (if not, why click on the thread?!? :twisted: )

4) quick youtube video going over the typed out mess of words above
https://youtu.be/hBOlqrsdyIU

*okay, I guess I didn't cover as much as I was expecting to... but, honestly... how often do I not make stuff too long? What did you expect in this thread then?


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## jason_recliner (Feb 26, 2018)

Great post Topher!

The only thing I suggest is do consider discharge as well, rather than "it usually doesn't matter". Most Li batteries are rated up to about 2C, i.e. a 2000mA cell might deliver 4A. Now, you did say that as long as they don't drop below 2.7V, and I'm too lazy right now to go digging up internal impedance figures to see how low a charged cell will dip. So you might be right all along, but you should at least give it a thought. I don't like to take them below 3V o/c, which is commonly considered _dead_ flat.

Here's my contribution for suggested use:

I recently made good use of half a dozen or so dead laptop batteries I collected at work over a couple of years. My 25yo motorbike's has always been a predator to its lead acid battery. They're short lived and seem to quickly hit a high impedance. On the most recent one's utter last legs, (having roll started it), I measured 13.6V at idle and 15.7V at 5000rpm! No wonder the damn thing is killing my batteries!

So after a week or so on the lab supply / volt meter, separating about fifty 18650s into Good/Ok/Crap, I made a 24x brick of 4 cells high and 6 cells wide which gives me a 12.0 - 16.8V battery with maybe 6-10 Ah (about 200x my lead acid battery's). No control circuitry required, since it will never exceed 4.2V/cell.

Disclaimer: If you are reading this and want to try it, you need to be very sure you consider peak discharge current, which is ENORMOUS. I soldered the pack together simply, and used jumper leads for a first test. Those little metal tabs on the batteries are not enough to start a bike. It glowed like a toaster and I melted the insulation on the jumper lead that touched it. Back to the soldering iron for a heap of copper sheeting between every group of cells.

I'm four months in, and it's still starting every time.

I have several more good, ok and crap cells, so I'll be watching this thread for other potential uses.


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## Topher_osAUrus (Feb 26, 2018)

Yea indeed, the suggested low end potential rating for most lithium batteries is the 3V, with 2.7V being the lower end for what most charge protrction circuits will happily recover and refill without giving too much grief along the way.


There are several points that I missed in that pretty lengthy post, one of them (which is pretty important) IS the peak discharge rating, which the highest I have seen so far is the 2C rating you mentioned. Even at that high rate of discharge, lithium batteries hold up well, and can generally get 75%-85% of their useful charge put to work at that rate, and the higher temperature that goes along with it.

One little bit of food for thought, is those of us in colder climates may have issues with lithium batteries abd their efficiency when the temperature drops relatively low. I cannot recall exactly what temp/% numbers are, but, I believe anything below -20C and the batteries come close to 0% efficient. 

The implications of that can be pretty troublesome should one be using the cells in a motorbike on a cold winters day. Possibly a hand warmer in the cells mounting location 20 minutes before start could make sure they have their ESR at an acceptable level for usage. Or, a removable pack that can come inside when not in use is a solid idea. That is why I ordered a couple more of the "laptop charging power banks", so they are a 2.1mm jack away from hookup or disconnect.


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## jimdoc (Feb 28, 2018)

Teardown of a faulty Samsung lithium 18650 cell. (2200mAh)

(So you don't have to)


https://www.youtube.com/watch?v=gYFuVbZmu5M


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## Topher_osAUrus (Feb 28, 2018)

jimdoc said:


> Teardown of a faulty Samsung lithium 18650 cell. (2200mAh)
> 
> (So you don't have to)
> 
> ...



Haha!
I love big clives videos

A bit of a tangent, but, this is my favorite.
https://youtu.be/mcDgOGC5Lcc
By far


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## anachronism (Mar 1, 2018)

Yep that's funny. About as dry as dry gets...


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## Topher_osAUrus (Mar 4, 2018)

Got a small shipment of batteries in and got them tore apart. Thankfully they came apart easily, and with great luck, they all are holding a perfect charge.

Dell ones seem to screw you though, they had 4 open spots for batteries, but no batteries.... jerks.
Anyways, 15 red body green top, 6 green, 6 lime green. all 2200mAh batteries.

-For Desmond's dump truck, I tried hooking the laptop charger 18650 bank (6s, -2p2p2p- config, with up to 21V output), and it wouldnt stay on. Seems the "smart" charger only stays on if a direct load is attached to the output. Well, then I hooked up the boost/buck module I had and WOW, did it turn them wheels slower than ever.
My guess is not enough amperage is moving through the itty bitty wire and in that module. I think its only rated for 1 or 2 amps. And the 2.1mm barrel jack had angel hair thin wiring. 

Next, I am going to try the big dog boost converter that I just fixed up. Bought it for $6 on ebay, the hexfet that was a dead short ended up costing me $9.. So, all in all I spent $15 on a $130 boost converter. It will crank out up to 120V and its rated for several hundred watts. 

Hopefully that features more success than before, but if not. I have "proper" stuff on its way from over the sea's.
https://www.ebay.com/itm/12V-14-8V-4S-60A-BMS-PCB-PCM-for-LiFePO4-18650-26650-LIPO-Battery-with-BALANCE/272646857507?hash=item3f7b04e323:g:wmIAAOSwtZJZATYN
...which looks identical to the one that says its made specifically for iron chem lithium batteries.. That gamble (buying it overseas with limited information) may bite me in the rearend... I guess time will tell.

As far as hooking the batteries up to that, I bought some 4S parallel 18650 holders that look decent... hopefully decent enough to withstand the soldering iron for a minute while I tack on some sense wires and current carrying wires. I did buy extra though, so if one doesnt survive the solder, I will change my plan of attack and just crimp the things on. 

I've rambled on enough I suppose.
no I havent

Im ordering some of these too. Desmond's Tractor is going to be done in style. His dumptruck is the proof of concept
https://vruzend.com/product/vruzend_basic_kit/
---thanks to Jim for the link in the other 18650 thread
(which is really close to this ones theme...so much so in fact, that I probably should have just added on to it...sorry)


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## Shark (Mar 4, 2018)

anachronism said:


> Yep that's funny. About as dry as dry gets...



I don't know about dry, but the look on his face was hilarious!


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