*Dusting off the 1000lb of laptop batteries

[999zip999]

Organization. Plus get rid of dead cells and with low voltage 2.8~3.0. Recycle. Get rid of them that way you will be able to concentrate on cells good enough for an ebike. Your right on a 15amp or so controller for them to last with larger parallel strings.

 

[dequinox]

Tonight I finally got around to opening and dumping out the first box of these. I've got the contents sorted and tallied in a google spreadsheet which I have shared for viewing, here.

Pictures to follow.

 

[DrkAngel]

For maximum usability-saleability ...
I would recommend resorting boxes.
Organize in lots of same brand and model of packs.

 

[dogman dan]

I was considering a buy, but I'd HAVE to get all the same brand and model cells in the box. Or at the very least, same brand computer labeled.

Some kind of sorted to closer to the same cells.

 

[dequinox]

For maximum usability-saleability ...
I would recommend resorting boxes.
Organize in lots of same brand and model of packs.

After seeing the contents of the first box, and seeing the higher % of generics... I am seriously considering it. My prices will have to go up from $0.50 / lb though to cover my time sorting them. I will have to do sample cell recoveries on each brand too... for now I'm going to stick with a "if you want a sorted box of cells, you'll need to contact me directly and we'll work out a price for them" policy.

I was considering a buy, but I'd HAVE to get all the same brand and model cells in the box. Or at the very least, same brand computer labeled.

Some kind of sorted to closer to the same cells.

See above, and when did you change your username??

Also remember this box would have been $25 + shipping from 97402 to your location. It gets spendy in NY, but aren't you in the southwest somewhere?

 

[dequinox]

Ok photos and comments:

The first box I'm attacking is a 50 LB box, the packs are loose inside with the terminals covered in packing tape.

View attachment 1
The packs at the start of sorting, and finished w/ labels. The 3 that are unlabeled are in a catagory I'm calling Other Namebrand (in this case a samsung, a sony, and an IBM pack).

 

[dequinox]

Here we've got photos of the individual groups:

 

[DrkAngel]

For maximum usability-saleability ...
I would recommend resorting boxes.
Organize in lots of same brand and model of packs.

After seeing the contents of the first box, and seeing the higher % of generics... I am seriously considering it. My prices will have to go up from $0.50 / lb though to cover my time sorting them. I will have to do sample cell recoveries on each brand too... for now I'm going to stick with a "if you want a sorted box of cells, you'll need to contact me directly and we'll work out a price for them" policy.

I was considering a buy, but I'd HAVE to get all the same brand and model cells in the box. Or at the very least, same brand computer labeled.

Some kind of sorted to closer to the same cells.

See above, and when did you change your username??

Also remember this box would have been $25 + shipping from 97402 to your location. It gets spendy in NY, but aren't you in the southwest somewhere?

I am pretty sure ...
Anyone interested in recycling Lithium cells would appreciate and gladly pay more for matched battery packs!

For potential customers:
With most laptop battery packs, there is no feasible way to measure cell or even pack voltages.
Busting them open to measure voltage is considerable effort and liable to endanger shipping safety!

As an alternative - I have carefully 1/8" drilled the ends of a pack, carefully turned in sheet metal screws till contact, attached charger leads and run a metered charge-discharge cycle.
Also possible to carefully drill between center cells for balance charge-discharge - (to evaluate packs for my computer shop inventory).
Cut stir stick-straw etc. as depth gauge-stop over bit.

 

[dequinox]

Second box stats are posted here.

I actually found one apple pack with 18650's in it... most have been prismatic cells so far. I'm curious to see who the manufacturer is...

Photo to follow. I'm just going to post the wide shot of the arranged cells for the next few unboxings, and then I'll show how I'm storing the sorted cells. Yes, i decided to start sorting these by brand. See the spreadsheet above for the breakdown so far.

 

[dequinox]

Box 2:



The one in the middle is the Apple pack, and the 4 in the lower middle are what I've designated as Japanese Cell Mix... a blend of cells the packs say are produced in Japan.

 

[dequinox]

For those of you waiting on word on the recovery rates for these cells I apologize. Again, this is a lengthy process for me as I've got a lot of other things to take care of on a daily basis.

Right now I'm in the midst of trying my hand at a tool-pack 18650 recovery. I had acquired several makita and milwaukie tool packs, and I am now in the process of tearing them apart and checking voltages to see what's viable. Some were completely dead, but I got more than a few with 75% or better potentially (3v or better) recoverable cells.

More updates when I get my setup running and processing cells.

 

[dequinox]

I added a 3rd box to the spreadsheet here.

Also I was wondering if anyone could direct me to a decent time-delay relay. The requirement is that it will handle 15A 120V AC and be adjustable down to 0.1 of a second... a range of .05 to 2 seconds or something similar would be nice. I am hunting for it as I wait for an answer from anyone interested too... but I haven't come to a conclusion yet as I don't know relays all that well. I'm using it for a battery-tab welder build... cobbled together from a microwave transformer. Expect more on this later.

 

[markz]

Yes I want to build a transformer welder too, microwaves are free junk in alleys. I wonder if it will do a decent weld.

 

[John in CR]

+1 regarding DrkAngel's earlier suggestion of keeping the factory tab welds intact, because removing them increases your work by at least 5X. I've only recycled powertool packs but the concept is the same and with powertool packs removing the factory tabs increases your work by over 10X, and when you've processed thousands of used 18650's you learn the easy way.

Removing the existing tabs not only greatly increases the work, but it also loses good information, and with laptop cells I'd keep the separate strings of each pack together to retain the most info possible. That info is that the cells in a pack are the same type, age, and have the same number of cycles, so cells still in balance are well matched. Bad or weak cells in a pack are easy to identify. Also, the cells and the factory tab welds of well balanced cells are already proven to be good by withstanding the tests of time and use, which (other than capacity) makes used cells better than a pack of brand new cells.

 

[dequinox]

Yes I want to build a transformer welder too, microwaves are free junk in alleys. I wonder if it will do a decent weld.

I will surely let you know if it pans out.

 

[dequinox]

Boxes 4 through 7 are now posted on the spreadsheet.

Also, this is how I'm storing them until I start ripping the packs apart:

 

[dequinox]

Ok so I built a little charging manifold over the weekend, and here are the results:

The initial benchtop shot... what a mess I had to cleanup to get it this nice :lol:


This is the bottom of the battery holders I'm using. They have little tabs that I had to bend outward to solder to without having to use a bread board. I didn't want to spend $$ on a board as long as I was going to need...



...so I put them on a board. Made from pallet wood...and I attached them with hot glue.



I then flipped it over and started soldering them to positive and negative rails.




I didn't want the wires flopping everywhere so I secured them like this:


Once everything was all professionally secured , I went ahead and hooked it up to the Accucell8 for a charge. I guessed at 1 amp per cell for the charge rate, after looking these cells up I determined their factory capacity at 2.2Ah, and set the charge at about .5C per cell. This was just an initial test, I don't necessarily intend to make this my final procedure. These cells did ok...the one on the end got hot toward the middle-end of the charge, which tells me it's probably diminished in its capacity from the other 3. Any comments are welcome... and yes I intend to get another read-through of DrkAngel's guide before I move ahead.


Also, noticing the massive difference in readout from the Accucel to the Harbor Fake multimeter (0.17V)...it's clear to me I need to invest in a decent multimeter for this sort of work. Even if it's just to check my other voltage monitoring devices (see the discharge setup post that should be coming soon).

Bonus points for those who ID something to indicate how I intend to put my packs together in the first photo... should be pretty obvious.

 

[amberwolf]

Also, noticing the massive difference in readout from the Accucel to the Harbor Fake multimeter (0.17V)...it's clear to me I need to invest in a decent multimeter for this sort of work.

Or just change the 9V battery in the HF meter--it's probably not very good when it's made, and by the time you get it it's probably aged/drained a fair bit.

 

[markz]

Yes HF probably buys the cheapest batteries they can, like any other electronics device. I always see no name brands that I have never heard or seen before. Just hit up any store and buy brand name battery. Those Crap-O-Rama batteries are bad!

 

[Doctorbass]

Ok so I built a little charging manifold over the weekend, and here are the results:

The initial benchtop shot... what a mess I had to cleanup to get it this nice :lol:
View attachment 9

This is the bottom of the battery holders I'm using. They have little tabs that I had to bend outward to solder to without having to use a bread board. I didn't want to spend $$ on a board as long as I was going to need...
View attachment 8
View attachment 7

...so I put them on a board. Made from pallet wood...and I attached them with hot glue.
View attachment 6
View attachment 5

I then flipped it over and started soldering them to positive and negative rails.
View attachment 4
View attachment 3
View attachment 2

I didn't want the wires flopping everywhere so I secured them like this:
View attachment 1

Once everything was all professionally secured , I went ahead and hooked it up to the Accucell8 for a charge. I guessed at 1 amp per cell for the charge rate, after looking these cells up I determined their factory capacity at 2.2Ah, and set the charge at about .5C per cell. This was just an initial test, I don't necessarily intend to make this my final procedure. These cells did ok...the one on the end got hot toward the middle-end of the charge, which tells me it's probably diminished in its capacity from the other 3. Any comments are welcome... and yes I intend to get another read-through of DrkAngel's guide before I move ahead.


Also, noticing the massive difference in readout from the Accucel to the Harbor Fake multimeter (0.17V)...it's clear to me I need to invest in a decent multimeter for this sort of work. Even if it's just to check my other voltage monitoring devices (see the discharge setup post that should be coming soon).

Bonus points for those who ID something to indicate how I intend to put my packs together in the first photo... should be pretty obvious.

If you parallel various cells from various state for testing or assembling , make sure these dont have more than about +/-200mV diff from the highest voltage cell to the lowest.. this will avoid overcurrent charging the lowest with the highest at too high rate :wink:

It all depend on the Ri of the cells to take high charge current...

Doc

 

[Hillhater]

I also have to say , that i think it would be a good idea to keep the cells tabbed together in pairs as they were in the packs and just treat them each as one larger cell.
They have been cycled that way many times, so will be well matched and if nothing else it will save you a ton of time de-tabbing and testing , but also makes assembling into bigger packs a simple, no risk, "soldering to the tab" task.
Also, not a priority but.. i would suggest you do a few tests on some of those low voltage cells ( <2.5v) which some have said to throw.
If they are a brand name cell, i have had much success recharging them, even after many months (years ?) of "resting"
It can be tricky persuading a LiPo charger to start them off with, but my RC charger on NiMHi setting gives them a pulsed current cycle no matter what voltage they are. It only takes a few mins to revive the base voltage to a level (3+v) so a LiPo charger will work normally.
obviously do the usual capacity,IR, and drain tests to verify cell useability, ..but just a suggestion

 

[dequinox]

That's interesting about the nimh charger jump staying recovery of the sub 3v cells... I hadn't heard about that before.

I also have to say , that i think it would be a good idea to keep the cells tabbed together in pairs as they were in the packs and just treat them each as one larger cell.
They have been cycled that way many times, so will be well matched and if nothing else it will save you a ton of time de-tabbing and testing , but also makes assembling into bigger packs a simple, no risk, "soldering to the tab" task.
Also, not a priority but.. i would suggest you do a few tests on some of those low voltage cells ( <2.5v) which some have said to throw.
If they are a brand name cell, i have had much success recharging them, even after many months (years ?) of "resting"
It can be tricky persuading a LiPo charger to start them off with, but my RC charger on NiMHi setting gives them a pulsed current cycle no matter what voltage they are. It only takes a few mins to revive the base voltage to a level (3+v) so a LiPo charger will work normally.
obviously do the usual capacity,IR, and drain tests to verify cell useability, ..but just a suggestion

 

[Hillhater]

Yes, it's just a cheap Turnigy "Accucell" charger.

 

[DrkAngel]

Mutimeter reading lower than charger is normal. (at battery)
Line (voltage) drop from charger >> through regulation circuit >> through wire leads is very noticeable, especially at higher current-charge rates.
(Check multimeter battery voltage though!)

A laptop cell getting warm at .5C charge rate could indicate severely reduced capacity.
More often, this indicates the cell self-discharging = internal short!
Must be removed from parallel charging circuit or alternate cells will never reach desired voltage.
Must not be built into battery or pack will be continually unbalanced.

A BMS can allow reasonably safe use of slightly self-discharging cells ...
but will function by continually discharging all "good" banks, ... that don't contain self-discharging cells! (Idiotic! ... IMO)

 

[dequinox]

I had considered maybe using one of the 3 BMS I have on hand (of which I've yet to determine the maker), but I'm not sure these were setup for the li-ion voltage. I believe these were meant for LiFePO4 cells. The BMS may be able to deal with the higher voltage, but I'm not sure about that. I think I may just end up relying on an RC charger to do the dirty balancing work, and keep a CellLog on the pack (or something similar) when in use to watch balance.

Mutimeter reading lower than charger is normal. (at battery)
Line (voltage) drop from charger >> through regulation circuit >> through wire leads is very noticeable, especially at higher current-charge rates.
(Check multimeter battery voltage though!)

A laptop cell getting warm at .5C charge rate could indicate severely reduced capacity.
More often, this indicates the cell self-discharging = internal short!
Must be removed from parallel charging circuit or alternate cells will never reach desired voltage.
Must not be built into battery or pack will be continually unbalanced.

A BMS can allow reasonably safe use of slightly self-discharging cells ...
but will function by continually discharging all "good" banks, ... that don't contain self-discharging cells! (Idiotic! ... IMO)

Thank you for letting me know about the warming during charging. If I'm charging I should pull the ones that are heating up ... got it. I'll keep the charge rates at .5C or less too, just to be on the safe side. My charger says it's 7 amps rated, but I've never seen it pull that. The most I get is abour 4-5A. If I have 15 parallel cells at a (theoretical) capacity of 1.5AH, my charge rate should be 11.25A or less... do I have that right?