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

They all sound like Sanyos. I think the red wrap means 3.7v nominal, 4.2v charge termination.
Light blue is probably 2,600 mAh, green might be 2,400 mAh. I don’t know about the Blue, but given the rating from the pack, I’d guess 2,600 mAh too.

Is it just me or does it make sense to get a charger that can give you either iR (Internal resistance) or mR (mean resistance) reading right up front, so we can consider if we even want to put a specfic cell on a charge cycle?

I have had great luck with the LiitoKala Engineer Lii-260 and Lii-300.

for half of what a resistance tester costs I get a charger for free. and with no fan noise.

my $.02

Yeah, I’ve done that before. In fact, that’s what gave me the idea for using this wall-wart to do the same thing. My NimH charger didn’t have slots big enough to stick a 18650 into, so I had to cobble something together with wires and magnets to make it work. This, I just held in my hand, holding the bare leads to each end of the cell. If it hadn’t jumped up in voltage so quickly doing that, I wouldn’t have bothered with them any further. But, to go from 0.26v up to 2.5v in less than a minute made me think it might be worth trying to get a real charge into it, especially since they are supposed to be new, never used. I still have yet to get a full charge, though. I put them back into my charger last night for a few hours, but again had to pull them before finishing, because I’m not going to leave them charging overnight at this point. After last night’s charge, they measured around 4.0v each. I wish I had a hobby charger to test capacity and run-time.

All the 18650 cells I have are pulls from DEAD laptop batteries. The highest any of them tested when I pulled them was around 4.0v, IIRC. But, a lot of them tested below 3v, and some tested below one volt. I even had a really old pack in which none of the cells tested above 0.9v, and I was able to get a charge into most of them. Did I happen to mention I’m partially insane? When I was a kid, my favorite things to play with were the dangerous things. I liked fire, electricity, strong chemicals, and sharp knives. I’m only a little less crazy these days. J) But, let me reiterate that I thought these cells would be NEW and that’s the only reason I bought them. I can’t return them, because I tore the pack apart, so I’m trying to see if there is any hope for them.

I bought a ‘New’ generic laptop pack off eBay and it was completely dead. All 6 (unbranded) cells were reading 0.4v or less. Luckily the seller gave me a full refund without question. Just as well as I had already ripped the pack apart. :wink:
As I had nothing to lose I s l o w l y got them up to 3v using the NiMH setting on my hobby charger, then a normal LiPo charge at 0.5A. All 6 got to 4.2V without getting even warm and all have been working fine in low-amp lights ever since. Capacity is about 60-70% what it should be but as they were free and I have 6 to play with, I’m happy.

Do you know if there’s some place that I can check
to find out the actual Brand name and mah info of
any batteries based on the numbers & symbols that
are printed on them , when no Brand name is ?

Correct this if it is not right but in considering testing/charging laptop pulls in order to get an idea if they are safe or not it would be good to

1) Check if the battery has about 2.5V minimum first. If under 2.5V-toss into the recycle bin.

2) Attempt charging and check the temperature while charging so it does not get too hot. If too hot take off charge and toss into recycle bin (after it cools down).

3) Take out of the charger after at least three hours and measure voltage having let the battery sit about two hours to see if it has retained at least 4.1V. If the voltage has dropped under 3.9 V then toss into recycle bin.

This is considering one does not yet have a charger/tester that can measure internal resistance or capacity (mAh). Later when a charger/tester is obtained that can measure internal resistance and capacity how and where in this example would these fit in?

Also if the new capacity in mAh is not available what should be done?

Does this about sum it up safety-wise?

One other thing is that the flashlight to be used if the batteries turn out all right is a single 18650 light.

The charger will be some simple 18650 charger with one slot and not digital.

Thank you for any advice.

EDIT - Changed minimum voltage.

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.