Here is a good used source for 18650 batteries

[eccerr0r]

Dammit. killed three pouch li-ion cells by overdischarging. Was always looking for a protection board but too late, overdischarged. At least I don't need to look for a protection board anymore...

Alas, now need to dispose of these cells.

[petehall347]

Originally Posted by sam_sam_sam

What are you wanting to do I might be able to help you with it

I know where you can find good quality used cell in the USA in the United Kingdom I can not tell you where you can find but if can find a company that recycling medical equipment batteries that would be your best bet or a company that recycles internet modems batteries is another good source for batteries

But you would need to have a battery spot welder to put on the tabbing you can solder them if cut the tabbing in such a way that you can still get the batteries out of the battery holder if they have them if they
not have holders it is easier to work with but you would need a dermal cutoff wheel 1” to 2” in diameter and carefully to not damage the battery cell it can be done because I have done it this from time to time

What I am doing with the ones that I am buying is making a cell phone and tablet battery packs that have a very long running time because the ones I can find use some very questionable quality batteries the USB charger/power supply boards for the most part are very good quality for the most part

was thinking of going into recycling . the way it is now it seems people just give them away at plenty of places . way i see it pretty soon they will become a huge problem and need dealing with . especially with them pushing battery cars on the populations these days . was thinking it might be a better prospect rather than salvaging to give more life .

[eccerr0r]

I don't see how recycling can be easily done.

Unlike lead acid batteries with huge plates that are not oh-so-thin you can grab all of the lead in one shot.

With lithium ion, you have to unroll the stack. Plus as you unroll it could go up in flames, so you have to do it in an oxygen free environment. And unrolling them, can a machine do it, undo the crimps, unknown what type of cell it is (manganese, cobalt, iron phosphate, ???) And what kind of electrolyte is it, if it doesn't all vaporize?

If all cells were standardized to 18650 and of the same mechanical construction, perhaps someone could design a machine to open and pull the pieces apart in an inert environment, but the capital investment to make such device would be quite high. Did I say it needed to be in a sealed, inert environment, in case something sparks it won't go up in flames? And it still could get mighty hot during disassembly if it shorts!

Then what about all these zillions of pouch cells out there with yet different mechanical design that won't go through a cylindrical 18650 process...

[diif]

They are currently recycled using mechanical and hydrometallurgical processes.
What's your background eccerr0r, what sort of engineer are you?

[eccerr0r]

Well, of course the "ideal" case is to use some sort "crush them all, god will sort them out later" type strategy (mix everything together, then use chemistry to extract ions) but this requires considerable chemical recycling to be environmentally feasible and cost effective. This "kill it all" type of deal actually could work with lead acid batteries because the salvage chemicals in the battery are all the same - the two lead plates can technically be treated the same, with the positive (PbO2) or discharged (PbSO4) plate metallurgically could still be treated like lead. And lead compounds of all types can be reduced to lead much like lead ore.

Much more difficult with li-ion cells. Lithium and the copper need to be separated from each other as though they are distinct metals. I suppose using water to separate copper and lithium is a first pass chemical separation since lithium is water soluble and copper is not, extracting lithium back from the solution is energy expensive, electrolysis is pretty much the only way. And still have to deal with the separator and remaining electrode.

Plus mining lithium at least right now is not all that expensive...yet.

(One other problem that was forgotten in the initial analysis is the separation of the cells from each other... with people making all sorts of cell configurations, this too would be difficult for a machine to separate to individual cells.)

What makes anyone think I'm an engineer?

[sam_sam_sam]

Well I bought 4 more of these battery packs and the results are lot better than what I expected but the sad part is the BMS balancing protection boards are bad on 3 of and the voltages very close to each other banks and seem to charge up with no real issues

The only one that the BMS balancing protection board seems to work but I have to change the power connector before I can test it correctly and see how well it works

So this lot of pad for it self

I going to load test some of them tomorrow and I will post the results

[sam_sam_sam]

Update on these battery packs —>

https://batteryhookup.com/products/2...cents-per-cell

<—

The results so far is over 9000 milliamperes hours and still at 11.54 ( 12.60 volt battery pack ) [ but only charged to 12.40 before load testing ] volts on the two battery packs under test right now very good results for something that is used and bought for salvage

I have not decided what I going to do with the ones that the BMS balancing protection board are bad because I do not know what voltage I going to need but I do need a 32 volt BMS balancing protection board for a solar LED lighting yard project that I want to do

I am having a hard time finding a 32 volt one I can find a 36 ones and if I go this route then I will have to use a PWM controller to reduce the voltage to limit the current to the LED lighting panel which I am not totally against but I would have rather just use a current limiting resistor for this project

I will post the results when the testing is done with the pictures of the battery pack and how I have it setup

I would have posted the link to them but they are not listed anymore so they are out of stock or they are getting any more of them ( the price was very reasonable for the name brand batteries ) so I might have bought what they had left

I also bought some 12.60 volt batteries packs that the results are decent for the way they are set up
These are nice they have a very simple protection board that seems to work I have not charged them all the way up yet ran out of time yesterday afternoon and did not want them to charge by them self until I have done this a few times to make sure that the protection board works correctly or not

I also bought some 16.80 volt batteries packs that the results are decent for the way they are set up
One battery pack was totally useless because 4 cells are leaking or showing signs of leaking and two more of that did not show signs of leaking but all are completely dead no resistance reading which means that the CDI has tripped two of that are left are at about 2.volt something but these are a non brand name batteries which I not going to trust for anything that has any real current draw on it
BMS balancing protection board on these are simple but I do not have the connector for them so I have to remove the BMS board and replace the connector to what I have and do some testing on these BMS

I will post some pictures of these battery packs later on today

[sam_sam_sam]

I have a correction to make I was not discharging the batteries I was charging them to 12.40

One note these batteries start a about 2.5 volts for each cell or maybe a little bit lower than that

When I first started charging them because the battery voltage was so low I only charging them at 80 milliamperes when they reached about 11 volts

( one battery pack at a time because of the software of this battery testing machine I can only see one screen on top I would have to click on to the other screen because I was doing other thing I only wanted to see real quickly where and what the results are at that given point in time and do a temperature check as well )

[ someone might think that I could open two screen on the computer and I could have done this but I was also using the IMAX b6 charger at the same exact time but this software for the battery testing machine has slight issues when you open two separate screens it does not always want to behave it self in this mode of operation I do not feel like dealing with it so I don’t ] plus it is more difficult to save the individual screen and bring them back up for use later is another reason I do use dual screen

I took off the charger and let them sit for a week to see how much they dropped off in voltage which was not much

Through out this hole process the battery have not heated up at all

I will load them at 1 amp and charger at 1 amp and see if the results are any different from the way I have been charging them to bring out of sleep

When I have finished this charging/discharging cycle then I will discharge at 2 amps and charge them at 2 amp which I will have watch closely for any issues that might arise

I have no plans to use any current higher than this for charging or for discharging them

On another note I only do battery testing on my days off when working on battery that I am not sure of what and how they will charge or discharge ( so I can sleep in peacefully with out worrying about what happens to them when I am sleeping )

Disclaimer

Your results might be different than mine if you were to buy these battery packs because I have bought some that all the battery cells have had issues so please be aware of this when thinking about buying some if you have a use for the battery holder and for the outside case then it worth the money as far I am concerned if the batteries are also good but the BMS balancing protection boards are bad you are still ahead and if everything works you get a real good deal for your money but you have to have time to test the batteries and the BMS balancing protection boards

and

I would highly recommend that you at least have IMAX b6 battery tester or something similar at a minimum and that you use the plotting software so you can see the testing results ( this battery tester is very basic and the software is also very basic )

When this comes handy is because I have tested a lot of batteries before and I know what the charge and discharge curves are suppose to be and look like I know right away if the battery that I am testing is going give a headache testing them meaning that I have to adjust the current so that the curve cycle looks correct so I do not have batteries that start heating up on me and I have keep very close eye on them if I have to turn the current way down so the curve looks correct for that type battery because the battery testing machine that I have does not have a temperature sensor ( this a pit fall of this machine )

If I known that the battery might have a temperature issue charging them I will use the IMAX b6 charger for those batteries in question

[sam_sam_sam]

Update for the two battery packs that I have been testing for several days now
22 amp hour @ one amp load and another 2 hour above 500 milliamperes load of useable power very good results for these batteries well worth the money ( $14.00 each plus shipping $16.99 for both battery packs ) I paid for them unfortunately the BMS balancing protection board was not working correctly so I will be parting it out

[sam_sam_sam]

Originally Posted by sam_sam_sam

Battery Hookup is running a sale on these battery packs

https://batteryhookup.com/products/h...lg-18650-cells

I bought some myself

Here is some information about these battery packs I bought four of them and two battery packs were bad I am getting replacement battery because when I took them apart the cell voltage was at zero volts and no resistance on the cells except for four batteries might have hope because they have some very low battery voltage but question is are they useable

I have not taken the other two battery packs apart yet but the voltage gauge shows 75% on one and fully charged on the battery pack

I also have found a way to take these parts and use the cell with out removing the tabbing from the battery cells and remove the battery holder from the battery to use in another project

[sam_sam_sam]

Here is a very very good deal I have yet to see a battery below 2.50 volts and few I have tested I got at 2200 milliamperes hours

I had ordered 30 of them

https://batteryhookup.com/products/3...cells-with-pcb

I just ordered 40 more

[sam_sam_sam]

What is going to happen with these batteries that I have mentioned above will be a USB C battery pack power bank of about 2200 milliamperes hours X 9 cells =19800 milliamperes hours times 3 banks that are separated from each other by a 2 or 3 switches I have not decided this part yet if I have an issue with the battery gauge on the USB C power bank board then I will have to go to this setup

[sam_sam_sam]

I found a solution to a problem with using these battery packs and being able to use the BMS balancing protection boards on these battery packs

I found a company that sells the female connectors to able charge and discharge them using this connector

https://batteryhookup.com/products/2...cents-per-cell

I will post where you can find the connector however I will not post until next week because I want buy some first because I do not know how many they have in stock

Here is a company that you can backorder them from

https://www.newark.com/positronic/pl...pt/dp/67AH5565

But I charged two of battery packs that the BMS balancing protection boards are still working correctly I have two more packs that I still need charge up to 75% until I decide what I am going to do with them but I have to buy the connectors so I can use them

One note about these BMS balancing protection boards they do not limit the charging current to the battery and BMS balancing protection board so you have to limit the current to no more than two amps because at 5 amps a few minutes later the BMS balancing protection boards stops functioning correctly and is unusable

[eccerr0r]

I need to get or design a battery analyzer or something to test cells...
Currently can only guess by seeing which cells give out first according to the BMS.

[sam_sam_sam]

You could use a IMAX b6 version 2 battery tester and download the software application

( one note you do need to use the software to be able to plot the results correctly )

[ because the results on battery tester screen is self is total amount of milliamperes hours at the useable rate and the non useable rate if you need me to explain this I would glad to ]

Once it reaches 3 volts [voltage screen] look at ( time ) [current screen ] reaches 500 milliamperes look at
( time note this time value ) look at time on milliamperes hours and use the time value from the other screen screen for results one note about this value it depends on how low you want your useable current value to be I use 500 milliamperes for my current value @ 3 volts


The software is very primitive but would work for you if you look at the voltage and what point it drops to 3 volt and then go to the current screen and and look at what point is at 500 milliamperes and then go to the milliamperes hour screen then you would have your results

One thing I do like about this battery tester is that it has a temperature sensor that does work correctly but you do have to set it up correctly because the default setting is useless this is very useful feature if you have a battery that you do not know its history and do not want to baby sit it when it is on charging mode

This does take a little bit of work but is doable

The starting price of a IMAX b6 battery tester starts at $40.00 for one that is not a clone

If you are willing to spend double this amount ( around $100.00 ) then you can buy the battery testing machine that I use and have posted results of batteries that have been tested and you just have to program the set point for what type of battery you are testing

( one note I do not use the setting that the battery tester machine has in it data base because I do not like it’s setting )

***[ if you want me to explain what I talking about I would be glad to explain it ] ****
to me a lot easier to use

One other note about these two battery testers is the following

The IMAX b6 battery tester the current valves varies from around 50 to 80 milliamperes while charging and discharging which helps batteries that have issues but it takes longer to charge a battery also the cutoff voltage is 4.1 volts not 4.2 volts

Manual Mode

The battery testing machine the current is continuously the same exact current when charging and discharging until it reaches the voltage cutoff setting is reached then the current rolls out this is a disadvantage if you have a battery that is a heater cell because this tester does not have a temperature sensor cutoff now

***if use the factory setting for different types of batteries it then behaves more like the IMAX b6 battery tester ***

I hope this helps you

[sam_sam_sam]

Originally Posted by eccerr0r

I need to get or design a battery analyzer or something to test cells...
Currently can only guess by seeing which cells give out first according to the BMS.

If you use a IMAX b6 version 2 you can look at the individual battery voltages however you can not use the BMS balancing protection board on the battery you have to hook up the IMAX battery tester BMS balancing protection from the battery tester please be aware of this

If you design one your self please post what you come up with I would be very interested in what you come up with

[sam_sam_sam]

Here is a project for what I did with one of these battery packs

https://batteryhookup.com/products/2...cents-per-cell

Right now it has the Boston Power batteries in but I am going redo it and use the 18650 batteries in it instead

And repurpose the Boston Power batteries for something else that requires more current and more running time with a better BMS balancing protection board

[sam_sam_sam]

I have tested some of the batteries I am going to use in this USB battery pack

The useable amp hours is from 2040 to 2080 which is not bad for used batteries
Load testing down to 2.5 volts and looking at what amp hours are at 3.0 volts

The roll off voltage is little bit lower than 3 volts but it not exactly the same for each battery but for the setup that I am using it not going to matter that much

Now if I was going to use a BMS balancing protection board for a lot of cells more than 2 cells then I would also look at the roll off voltage and match them as close as possible for the best results

Which is a lot more work time wise

[sam_sam_sam]

Update the battery pack that I had posted a link on it that has 27 battery plus the battery holder and the outside case they are completely sold out the listing has been removed

Did anyone take advantage of them

[eccerr0r]

Anyone seen how those large 3.2V LiFePO4 cells are made, like those huge prismatics? Are they built with a ton of small cylindrical cells in parallel or are they one big cell? (Usually these are used for fixed battery banks it seems.)

Curious how these should be recycled... fortunately their cycle life is very long and won't need to be recycled for a long while.