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

Some light entertainment during the time of Covid-19 social isolation,
get around to opening a few laptop batteries I had salvaged.
Anyone else with unfinished salvage ?

I'm new to LiIon harvesting & only have experience harvesting two, old, used laptop packs. Those went OK, with one pack of 18650's testing @ just under 1,000mAh, the other set all testing ~2,500 mAh. I'll use the <1,000 set until discharges & discard them.

I was recently given a NOS HP laptop battery pack still in the HP box that is probably 10 - 15 yrs. old, at least. While disassembling, I noticed some corrosion where the wrap was deteriorated, exposing the can on two cells. There's also some minor blistering under the wraps of other cells (not pictured) that leads me to believe corrosion is growing under the wraps on those cells. In addition, I notice a sickly-sweet odor emanating from the pack. I don't trust these cells & the whole pack is residing outside until I visit a HD or other place that accepts cells for recycle.

Cells are marked LG CHEM.

The nick in the wrap above the code on the upper cell is my sloppy doing on disassembly.

Could someone please school me on the corrosion issue and perhaps the odor?

Thanks.

slmjim

Sounds like something leaked. Any time you have leakage, there’s corrosion too, so I’d be careful pulling that pack apart. The outside of the battery under the wrap is the negative contact, so be super careful with cells with damaged wraps because you can short them.

Well Since C-19 and getting batteries sent to Alaska. I have started relying on battery pulls for my 18650s. I need to find a source for 26650s.

I will post up a photo of what I have so far when I get home.

Hello all, I’m new to the Li-ion battery scene, and I have a question. I have a usb battery bank with 5 dead ICR18650-26A. And I want to replace those dead batteries with some ICR18650-26D I pulled from a laptop battery pack.
But I see that the max charging voltage for the ICR18650-26D is 0.1 lower than the ICR18650-26A so I’m wondering should I not attempt to use the ICR18650-26D charged to 4.3v which is 0.1v higher than their max which is 4.2v?
Thanks everyone :slight_smile:

Don’t charge 4.2V cells to 4.3V.

It’s fine to charge 4.3V cells to “only” 4.2V.

Ok thats what I thought, thank you!

Dunno any chargers that charge 4.3V cells (not that I particularly cared, as I don’t have any 4.3V cells). And if so, they’d better default to 4.2V unless manually and explicitly set to 4.3V. Ie, no slide-switch you could forget about and slow-cook your generic 4.2V cells.

Even my LK chargers will default to 4.2V Li-ion when I plop in a 3.2V LFP cell, which is a Bad Thing. And there’s been at least one time I almost forgot to switch it to LFP.

Years ago I bought an XTAR SP1. This is a 1-bay charger strictly for lithium cells.
It has a switch for LFP, 4.2V and 4.35V (though it says: 3…2V, 3.6V and 3.8V)
HKJ has tested it HERE.

Bought it because I got some Samsung ICR18650-28A for a mod with a high forward Voltage UV-led.

Especially in this time and age, my laptop isn’t a mobile PC anymore.
For me it’s just another desktop, always connected to a wall outlet.
And even if I had other plans, the age of it prevents prolonged stand-alone usage.

So I decided to break open the battery box and see whats inside it.
To tell you the truth: it wasn’t all that disappointing at all.

My Compaq Presario M2020EA had a battery pack with a sticker that says: TL 2004-11-09.
Containing 6 Samsung ICR18650-22B with capacities (Vapcell S4+) ranging from 1,818 –1,885 mAh.

.

You guys should check out batteryhookup.com
I’ve gotten tons of 18650 salvaged batteries from them.
Most recent was the 10lbs of tool batteries for $20, I got about 10 good Samsung 20Q INRs, 5 good random 1500mah IMRs (tested around 1100-1200mah) and like another 10 LG INR/IMR ones that test around 1800mah. Actually about a little more than half were good cells, the others either had internal shorts or were leaky and 0 volts (100% of the small 2AH ryobi tool packs were bad, the 4AH ryobi packs had the 20Qs). One of the packs was a Ridgid 3AH pack, and since I have some Ridgid tools, I just kept that pack untouched and currently use it since I previously had only one Ridgid battery pack for my 3 Ridgid power tools. One was a crappy 18v NICD pack so I immediately threw it away lol.
So I got about 25 decent high discharge 18650s (35 if you count the Ridgid pack) for $20 plus shipping, not bad!
Also their modem batteries are a pretty good deal too! I have about 40 of those and they were all 50 cents per cell and ALL tested 95% + capacity.
so I have acquired 65 18650 batteries (75 if you count the Ridgid pack) for about $70 including tax and shipping on 3 separate orders! (I should have made one large order lol, but they didn’t have the tool packs when I placed my first order…)
The only annoying thing I don’t like about salvaged batteries is the tiny spot welds are really difficult to make flat on the ends… but for this cheap, I don’t care!

I would not encourage anyone to buy batteries that are in a condition where people discard of them. Forget about the obvious monetary loss, it’s just plain dangerous.

A new battery is $5. That’s less than a pizza and a soda.

For the average newbie I completely agree with you.
You have to know what you are doing.

For people like me and others in this thread that salvage batteries, I completely disagree with you. The tool batteries are obviously used yes, but the 40 modem batteries are very lightly used if at all, as modem batteries are ONLY cycled if the modem has experienced a power outage. If anything they are “proven” to work.

I have tested each and every one of my batteries and know for a fact that the ones I have kept are GOOD batteries (no self discharge after 30 days, IR is within normal range, capacity is within 85%).

I have 65+ batteries, and no way in freaking heck would I spend $5 for each cell.

I got into 18650 flashlights BECAUSE of salvaged laptop batteries.

I have bought a 2 pack of BRAND NEW Samsung 40Ts and one of them had a somewhat slow internal short/really high self discharge, that would be completely unsafe to use for the average user as it would discharge itself to under 2.5 volts within 2 weeks, let alone a month or two.
Most of us here know that lithium battery cells should never be discharge or charged from that low of a voltage (less than 2.5v) and can be a fire hazard if they do.

The only lithium batteries I have bought new are 4 26650s and 4 21700s (2 40Ts and 2 P42As, btw P42As are much better…)

Sometimes logic can keep us safe, but if you are experienced and know what you’re doing, then logic is like a tutor, providing direction and guidance. I’ve salvaged dozens of laptop pulls and random other pulls, and out of those maybe 3 or 4% were unsalvagable and get recycled (never in the trash!). The rest are just fine for parallel applications behind a BMS or power bank, or other low-impact applications like testing leds or drivers or low drain devices. I do not recommend salvaging li-ion cells if you dont know what you’re doing and do not have the proper tools like special chargers, etc. Plus, it can be fun and rewarding. If you can get 4 good 2 Ah 18650 oit of a 6 cell laptop pack, that’s saved you what, $20 right there. I buy from thrift stores so if i get a 12 cell pack for $2 and it has 10 good 2 Ah cells in it, bam, just saved a bunch.

Is that table still being updated somewhere?

How do people deal with the welded tabs on the top of the batteries?

I use a small pair of cut off pliers and carefully cut between the cells — I then use a twisting (unscrewing) motion to break the welds — You can pry up slightly on the positive side —you don’t want to pry up on the negative side (it pulls the metal from the cell ) the positive side is thicker —- be careful prying around on the positive side ( the top edge is negative right up under the wrapper —- Do This Outside In Case You Short Out A Cell —— I’ve taken apart 1000s of cells —- I shorted one out on number 2500 in my office — I’m very lucky I was able to grab the pack and get it outside

you can find these anywhere

I pulled them off with pliers and then filed down the leftover nubs.

Thanks chops728, i did one battery a long while back and pried upwards as you say to avoid, albeit it with a rolling motion but it didn’t go well. And even though i knew not to short the positive terminal to the casing i managed it anyway.

It put me off trying again but i have 3 battery packs from my now defunct laptops that are calling louder and louder… :smiley:
I shall try the unscrewing method.

Thanks :slight_smile: