Look what I found in the recycle bin

OK, OK. Members solder blobs all over the place here and I get all the preaching? These 13Q can deliver 15A continuous and 30A bursts. The pack has 5P. That’s 150A to get the starter moving. Once moving, the current is much less. The weak point was the 12ga leads. The cells had no prob starting the car. Especially being at 18.4v. They didn’t even get warm. By the way. 5P means a cell can fail and there are still 4 cells to take up the slack. So bigger margin of failure. See the balancing jack? That’s so I can monitor the pack real time. I agree the masses need to be warned, but I know what I am doing.

I’m now reminded of the famous last words of a red neck. Hey you all, watch this.

Did you use it to jump start the car or start the car on it’s own?
Jump starting is a piece of cake for that pack.

Someone once pointed out to me that “only fanatics get anything done worthwhile” :slight_smile:

Yea, lets get down to the cold cranking amps. Lets see that pack start the car with no other battery attached. Then turn it off right away. Not sure how the alternator is going to feel about a bunch of li-ions connected to it….

I don’t know where gauss163 got jump starting from. I used the pack as the car battery to see what level the car would take it too in the absence of a lead-acid battery. The car (a 1995 Corsica with 3.1L V6) took it down to 14.6 volts. I wanted to know this as I am currently building a LiFePo4/Super Capacitor automotive battery.

Most cars are fine with 18v. Some people convert their cars to 16v batteries and those cars can go as high as 18-19 volts when running. Most report their cars start and run much better at the higher voltage.

The other day I found another very nice pack. This time a 5Ah DeWalt pack, and it looked brand new.

Look at the specs on this thing, 100Wh!!!

It has a state of charge meter on it but it didn’t light up, maybe the reason it was tossed. So I took it apart to see what was up. All cells were sitting at 2.67V, maybe just low enough that the charger wouldn’t recognize it. This pack contains 10 Samsung 25R’s.
So I charged this pack up manually, making sure all cells charged equally. I let it rest a day and then discharged it through a 3 ohm power resistor to measure the capacity.
Here are my data points, voltage measured across the 3 ohm resistor versus time in minutes.

This DeWalt pack has no Low Voltage Protection in the pack, it must be that DeWalt includes that in their tools. Because of that I had to monitor each cell as it was being discharged to make sure they all tracked the same so as not to over discharge any one. I shut the pack down at 14V as at that point each cell was at just about 2.80V while under load.

My capacity estimation for this pack is: (17.8V/3 ohms) * 50 minutes * (1 Hr/60 minutes)= 4.944Ah
This post explains why I use those numbers in my calculation.
I had to estimate the capacity of an 18V drill pack, here is how I did it.

it is not good to throw the half full battery away.

I found this huge Li-Ion battery pack in the recycle bin. What first caught my eye was the 3 brass “terminals” on the top and the digital readout. At the time I thought I found a portable power supply with binding post outputs and a readout. Turns out it was a battery pack for some sort of camera. This pack costs BIG MONEY when new.
Not much to say, here are the pics of the tear down of this pack.
Turns out the “Binding Posts” were just guides to slide this pack into the camera. :blush:


The digital readout, LCD?




13.6Ah and 204Wh pack!

At this point I thought I had 8 sub packs of 3 18650’s each. I took measurements across each subpack and it appeared as though 4 were dead. It turns out I was wrong.


This is what I think is the balancing board for charging and discharging this pack. I bought one that looks much like this to charge 4 cells in series off of eBay.

Now here is where I was mistaken about these sub packs. What I thought were 3P 18650’s are actually something entirely different. When I took voltage readings I measured some cells in the wrong places and got 0.0V for 4 of these 8. Turns out these are 1 cell each, and when I measured them using the correct lugs, each cell reads 3.60V :confounded:
This could have been a like new condition pack and I decided to ruin it taking it apart because I thought half the cells were bad.



I am on the road so I can’t test these cells for capacity, but because all cells were sitting at 3.60V and the pack looked to be VERY lightly used, or new, I may have destroyed a perfectly good pack out of curiosity.
I will post the results of the cell tests in a few days.
If they perform like new, at least I have the cells.

Those look like some big prismatic cells, at least compared to the ones I have.

Yeah, about the same size as 3 - 18650’s
I charged one up today to 4.20V and it held at 4.18v, Then discharged it in my OPUS B-3100
6868mAh capacity. From the description of this battery pack, they sound like they could be IMR type cells


The 2 readings on the right are a run test of a couple of 1500mAh Sanyo’s that I recovered from a new, but damaged drill pack from the bin

Wow, what a find dchomak. Congrats. You seem to feel the tear down was a waste, but look at all we learned from your teardown. Now to figure out where professional photographers dump there batteries.

I found another power pack in the recycle bin. In case no one has noticed, I have been posting the strange, rare finds to this thread. I would welcome anyone else also posting their unusual finds also.
Anyway, once again this pack looks brand new. However I suspect that it was to be installed inside of some piece of equipment. If that was the case, it could have been heavily used, but show no physical signs of wear and tear.
There it is. “36V/4.4Ah/158Wh

There are warnings right on the label, first warning is “do not disassemble or open”

Warnings aside, I did press on, very carefully. This is dangerous stuff, should not be done by anyone not knowing what they are doing. (I don’t either. But I am really, really careful :slight_smile: )
So I took the first 2 layers of shrink wrap tubing off. The tubing was at right angles to each other. At this point I can see that this pack contains 20 - 18650 cells in a 10S2P configuration. Also at this point I am guessing that these cells will turn out to be of ICR type and not IMR. Two 18650’s in parallel would give the 4.4Ah capacity stated on the label if each cell was rated at 2200mAh. Already this pack is a little less interesting to me.

There is only a 2 wire socket that plugs this pack into the unit. All charging and discharging is done through those 2 wires. After removing the shrink wrap, a circuit board is now partially exposed. Also I can see that the cells are purple. I like the color!
There were 2 layers of paper tape also wrapped around the pack, each once again at right angles to each other. Here it is with 1 of the layers of paper tape removed.

Now we can fully see the heatsink for any power FET’s that may be in the circuit. Also we can now see the sense wires going to each of the cells.
Here it is after taking the second layer of paper tape off. After noticing the wimpy weld joints on the tabs, I am now pretty confident that this is not a high amp pack.


As I mentioned, the weld joints are pretty wimpy. Here are the welds of this pack on the right and the weld joints of a drill pack on the left. A drill pack, with type IMR cells, are built for much higher current loads.

Recently there was a group buy on the forum here for some Samsung 30Q’s As IMR’s are manufactured for high current loads, the come with flat tops on the postive side. The intention being that they will be welded into a pack. Some of the members here opted to have a third party install button tops. I hope those button tops were welded with the same kind of weld as a drill pack. Worse yet, I hope the button tops were not merely placed on top and held in place with another layer of shrink wrap.
I have seen that done with some rewraps of cheap UltraFires where the original cell was a flat top.

Anyway, I didn’t even think to measure the voltage of the pack. Voltage across all 10S2P is 36.0V!
To me that is a VERY, VERY good number! It is possible that this is a brand new pack, having never been used. 36.0V is just what I would expect to see if it was. Had it been any other number, it would have meant that this pack was used. And if it was used, it’s condition could range from very good to very bad. Before I tear this pack down any further I want to test the cells to see what condition they are in. I also want to see if this pack will balance charge with just an input charging voltage. Most drill pack chargers that I see connect to a drill pack battery with 3 or 4 or more connections. Even when the BMS circuit is in the pack.


36.0V divided by 10 cells in series equals 3.60V per cell, and that’s what each pair are!

Does anybody recognize what these cells are? I am thinking they are 2200mAh, ICR’s
EDIT: According to the label outside the pack these individual cells shoule be 2200mAh each, however dividing 7.2Wh by 3.6V as per the cell wrapper, we get 2000mAh cells.

^

Thank you for another informative tear down dchomak. I don't recognize those purple ICR's.The SZNS makes them appear to be Chinese made, but that is a wild guess.

Pulled this one from an HD bin yesterday. Weird how it says 40V Max, but the cells should charge to 42 volts. Pack feels light for it's size because it has some empty space inside. No indicator lights came on. Opened it up. Build quality seems good. Had 10S1P Sanyo UR18650RX cells. Date codes were "T28", July 2015. So, pretty young. These cells are supposed to be good for 22amps continuous and have 2,000mAh capacity. Haven't tested any yet. They were at 3.26v - 3.27v. PDF

You and I have come across that “G Max” pack before. Me personally and you vicariously, thru me. :stuck_out_tongue:

Check out post 79 of this thread. (link only works with default BLF posts per page of 30)

Be careful with that one, a very wise person warned me :smiley:

Damn, dcho. You brave (or maybe a bit crazy). This thing looks like a short challenge with an attitude
.
.

Have fun, that pack yielded great cells for me.
a\also, save the connectors on the BMS board from that G Max pack. They mate with the connectors on the 18V Ridgid battery packs. Could come in handy if you want to use an 18V Ridgid to power some future project.
(Like maybe a combo Lantern - USB charger - MP3 player - Bluetooth Speaker - coffee maker) :partying_face:

that 36v is probably for a hoverboard.

specs
high drain type.score!

Ha! Now I know why I had a moment of Déjà vu when I first saw the pack. Glad mine only had 10 cells because that 20 cell pack you got looks intimidating to me.

Good sleuthing!

All I could initially find was some info on the cells. Pretty much all I could find was, as ImA4 guessed, they were Chinese.
But your info invigorated me, and I thought to scan the QR code on the battery pack with my cell phone app.

And you were right, this pack is a high amp pack that came from a hoverboard!

A…much…more…interesting…pack. :slight_smile:
Now I WILL test the condition and report back.

Here is the site the QR code scan led me to.

looks like it was designed to be safe.and not go nuclear if some kid gets it into a stall condition.
if those cells actually have the i.r shown they will be good for more demanding lights and tools.

Yes, apart from the welds it looks like it is well built. That BMS board has 4 power FETs. It’s not made super cheaply.

I am in the process of charging it up and I will discharge it through 6 ohms of power resistors. I shall report how it does.
In the mean time, I have another pack that looked interesting. I don’t have great hopes on the cells inside, I’m just curious to know.

This one is from a Defibrillator! This one must have some really high quality, reliable cells.
Whatever they are.

The top was glued on and came right off, revealing a circuit board,

The circuit board resisted a little, but finally gave in to my persuasion.
WAIT, what the?

.
.

Sorry, couldn’t help myself. I thought of this the second I pulled this pack out of the bin and saw it went to a Defibrillator :smiley:
What it really contained was this,

Boring, and they were dead.

Priceless my friend, priceless………… :smiley: …. . :+1: