BLF Community Battery Pulls Overview Thread (Laptop packs and Tool Packs)

i think that is good .

I think you are probably wasting cells if you pitch everything below 2.5V. I use 2v as my cutoff.

You should figure out the nominal capacity of the cell © with a little research and pick a charging current that is 0.2-0.5C. For example, for a 2,600 mAh cell, set the charger to between ~500mA and 1.3A. If you can’t find this info to a reasonable amount of confidence then maybe find another hobby, like origami (careful of papercuts though) because between the markings on the pack, the count and arrangement of the cells, should be enough to estimate the capacity, and the cell markings, Google, and this forum should help with verification.

I don’t know where you come up with 3.9v as the cut-off for resting voltage after a charge. 4.1-4.15v is probably more like it. Anything that has dropped to 3.9V is in really bad shape.

Internal resistance measurements from most chargers aren’t very precise/repeatable, and certainly aren’t easily compared to values using other test equipment and techniques. Once you get something that can give you a reading, you should keep track of the results you get and compare it to other results you get, like discharge testing to get a sense of good and bad. Also, for most lithium ion cells the internal resistance is supposed to be pretty consistent over the useful life of the cell, so its not a great fine-grained indicator of cell health.

As for discharge testing results, thats sort of up to you. A cell with less than 70% original rated capacity may not have much useful life left in it, but it may be fine for your purposes. I’ve put a few of them in cheap USB power bank cases and use them to power little USB LED lights.

One thing that I’ve found useful is to use an Arduino + the PackProbe sketch I wrote to dump the data out of laptop packs before I decide tear into them. Once you have it set up, it takes less than 5 minutes to use PackProbe to get manufacture date and cycle count, and often, the voltage of each bank of cells, which can be useful information before deciding to rip apart a pack and subject the cells to more extensive testing. It also adds context to the results of more time-intensive testing.

Are there any known tool packs to source 4.35v cells?

edit: or laptop packs

I don’t recall seeing any, but someone else may chime in.

High voltage cells tend to be focused on capacity, while tool packs tend to use cells optimized for discharge rate. For a given chemistry, cell designers trade discharge rate for capacity by changing the ratio between electrode material, and electrolyte. Moreover, different chemistries lend themselves to one application or another, and the cells used in tool packs tend to use a different chemistry than high capacity cells. I’m not sure, but the specific chemistry may also influence whether high-voltage is a viable technique for increasing capacity, but even if it is, it comes at the expense of durability.

Panasonic and now LG have lithium nickel cobalt aluminum oxide cells that deliver high capacity and moderate discharge rates (~10A) but I think they all have 4.2v charge termination.

-- PANASONIC TOUGHBOOK battery model # cf-vzsu46 10.65V 8.55ah > yields grey panasonic 2900 NCR18650

............................................................................................................

Hoover Linx Platinum 18 Volt Lithium Ion Battery; Fits Hoover Linx Platinum BH50000 BH50015 BH50010 >> yields 5 sanyo LMR UR-18650W2 1600mah pink around the top LMR

http://www.sears.com/hoover-linx-platinum-18-volt-lithium-ion-battery/p-SPM6085479708?hlSellerId=19994&sid=IDx20110310x00001i&kpid=SPM6085479708&kispla=SPM6085479708&mktRedirect=y

Thanks Boaz,
Update OP

Just did my first laptop pull yesterday. Yielded 6x 18650’s.

Manufacturer: Dell
Battery Part #: C1295
Battery Pack mAh: 11.1V 4700mAh / 53Wh
Cell Name: LG ICR18650-DA2E (cells say LGDA2E18650) (Grey wrapper)
Cell mAh: 2400mAh

I scored at the Best Buy today…16 different battery packs, including a few non-laptop packs, which have non-tamper screws on them. What type of tool do y’all use to remove them??? I’ll update this post as I tear them apart. Here is what I have:

1 x Roomba 14.4V Ni-MH
1 x Apple 10.8V Li-ion Polymer Mac Book Pro M/N A1281
1 x Duracell 6V Ni-MH DR10 camera battery
2 x Sony 7.2V Li-ion L Series Infolithium NP-F550 for Mavica HandyCam
2 x Ryobi 18V LI-ION drill battery P103
1 x Ryobi 18V LI-ION drill battery P107
1 x Craftsman 18V Ni-Cad drill battery 130260001(This one will probably go back in the bin)
1 x Toshiba 10.8V Li-ion battery pack PA3780U-1BRS
1 x Toshiba 10.8V Li-ion battery pack PA3534U-1BRS
1 x HP 10.8V Li-ion battery pack MU06 (593554-001 replacement no.)
1 x HP 10.8V Li-ion battery pack EV06 (474170-001 replacement no.)
1 x Dell 11.1V Li-ion battery pack Type J1KND
1 x Dell 11.1V Li-ion battery pack Type U4873
1 x Lenovo 10.8V Li-ion FRU P/N 45N1175 ASM P/N 45N1026

Are they brand new but unsold packs?

No…all used…just some put back in packaging.

eas - Thanks for your input and tips.

Samsung NC10 6cell (5200mAh) laptop battery (AA-PB8NC6B).

I expected something along the lines of Samsung 26F or so.
But inside were Sanyo UR18650FM N30B, stating so, embossed and as always barely readable, on the translucent red wrapper.

We always knew from the charts of lygte-info and dampfakkus that the Sanyo FM had some advantage over the Samsung 26F, but that Samsung would use them in their own netbooks…

Never saw this translucent wrapper on a Sanyo cell before, but the ring on the plus side is light blue as usual. In addition I’m pretty sure the battery I opened is genuine Samsung. I have 2 NC10 which I had bought new at the time and their batteries are identical to this one, which I had sourced from eBay. Opening was difficult, to say the least. I had to crack the casing but the real pain was the glue-tape inside, which was sticking terribly to everything it was attached. I had to rewrap the cells as some of the wrapping did not survive the disassembly.

The cells were down to 2.4V - 2.6V. I carefully charged them, temperature was not rising. As they held 4.2V pretty good for a day, I made several cycles with low charge and discharge current. They sat for a week and went from 4.21V to 4.18V. That convinced me to use them.

Capacity is between 2200 and 2300 mAh. That’s pretty cool for cells this age (N30B means 2009, week 30). But that’s only for lower current. At 3A voltage sag seems to be higher than it usually already is with these LiCo cells.

anyone have info on lgep218650 cells? think they were in a toshiba laptop. purple wrapper.

LGEP218650
5363100376
DL15404P2

that is what is printed on wrapper on one cell. not sure if the second and 3rd set of numbers are same on all 6 cells or not.

get us a photo of the battery and it would help us out more.

i will see what i can do. i dont have a very good camera

I found this battery pack in the recycle bin yesterday. It seems to be for some sort of portable Hoover vacuum. It was strange to see the old-fashioned Hoover logo on a modern battery pack. It had to be modern, it says Lithiium Life”.

Checking the back of the pack, it claims “20.0V MAX and 72Wh”
The 20V max probably means that it contains 5 cells in series. Most tool packs would call this an 18V pack, although some companies would call it a 20V pack, for example DeWalt.

But a rating of 72Wh means that this pack is rated at 4Ah and multiplying that by the “standard” rating of 18V for this type of pack would give the 72Wh rating. Can’t wait to see what’s inside!

There is a sophisticated BMS board with controller chip and 2 FET’s. I presume 1 FET acts as a switch to shut the pack down when any cell reaches 4.2V during charging, and the other FET acts to switch the pack down when any cell discharges to less than around 2.75V.
Now to see what the cells are!

There they are, this pack contains 10 - Samsung 20Q (20R), 2Ah cells (2000 mAh)! All cells were sitting at around 2.4V when I measured them. First thing I did was trickle charge them all up to 3.0V, It only took a about 10 seconds (a good sign). Now I am in the process of individually charging them up with my OPUS. Each cell-pair (5S2P configuration) so far has soaked up 4000mAh of charge (another good sign). I will report the final results later

I think this pack was a VERY good find, as it likely will yield 10 good Samsung 2000mAh IMR’s

EDIT: May 7, 2015

Turns out this IS a very good find. All 10 cells discharge to over 2100mAh. Most likely the reason this pack was tossed in the first place was because the included BMS board was bad. Even though the cells are good, the pack could not output through the board.
Samsung IMR 20Q’s are rated at 2000mAh, all of these cells test out at slightly over that. So all 10 cells are in “like new” condition.

Pulled these out from a SONY PSVITA 5,000mAh portable charger.

Anyone know what cells are these? they have no marking at all.

Those very much look like Sanyo UR18650ZT's

Hi I extracted some cells from a Dell battery. Pleaseehelp me identify them.

Also from another battery got Samsung 18650 - 26d Sdi cell is it 4.2 or 4.3 volts cell?

Imgur

So is there a trick to getting to rummage around in a recycling bin for these batteries? I have been nearly run out of two Home Depots and Best Buy looked at me like I had a second head growing out of my neck… They even had a “why would you want to drink the toilet water?” look about them when I asked at that Best Buy to look through the recycle container for the batteries. I have been polite and extremely neutral when they say it is “for my safety” that they cannot let me do this, but what kind of techniques have worked for others here?