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

2 cells tested.
2696 and 2698@1a
nearly new.

another doa mu06 replacement “5200mah”
6 red yle(yiklik) 2200.
all over 2300 and 60mohm.
still a lie but not as big a lie as others.
and these cells perform well at 3a in a s2+
seems to be a high % of doa with these packs.
but free cells!
i have yet to have a seller pay postage for return of the duds.
they know these packs have a high doa and its not worth the postage to get them back nor the time to test before shipping.

Nearly a year ago I got a replacement laptop battery pack for my old HP Probook, which must be maybe 8-10 years old. The old battery pack was lasting 20 minutes at best. The new pack died recently and was replaced under warranty with a very good one so I thought I don’t need the old original pack as a backup any more, time to strip it. I thought if I am lucky only 1 or 2 cells will be dead, and maybe I will get 2-4 viable 18650’s for use in low powered lights.

I was amazed when I pulled out 6 grey LG cells and tested them on my Lii500, all were within about 5% of 2000mAh, and all were sitting at about 4.05V after at least 6 months unused. They all have no problem running a Convoy s2+ 8x7135 on high, It must have been the circuitry that was faulty.

I will test them all individually for runtime, but such positive results make me want to hunt down more old laptops and then I will need more devices to put them in, and more chargers, and cases, and then I may need to save up for a divorce……

You guys know how it goes.

yes you are already too far down the rabbit hole to turn back.
and it is surprising how many useful cells lurk in “bad” laptop packs.
enough that folks build powerwalls with them.

Just a quick question - I have salvaged 18 ncr18650’s from a bosch drill pack (less than a year old), I noticed 1 cell with brown leaking down the side so I disposed of that one and I’m hoping someone binned a perfectly good pack because of 1 bad cell…
So I have kinda cut/snapped off all the little welded tags, but the cells are a bit rough/spikey sharp on the ends now where the contact welds were and some still have bits of bent tag, what do you guys do to remedy this? flatten them off I mean, a dremel maybe?
Thanks in advance :wink:

I just grab them with pliers and twist them off. Works pretty good.

Pulled some US18650GR (Sony) from a laptop battery pack. 8 cells, 6 were dead (0V), the other 2 were ~2.0V :open_mouth:

But I put those 2 in my Xtar VC2 and they charged (~2500mAh).

I’m back from a little hiatus…. My laptop pulls have been working great! My 91 cell ebike battery has held up quite well and right now it just sitting on my desk in our apartment office….little risky but shouldn’t be…lol I think my bms limits the current draw to 30amps on my ebike because even if I jam the throttle down itll only pull around 1300-1500w which is about 30amps. I took a nasty and very stupid fall on my bike one morning and that made me put the bike away till next year. Lol anyway

I’m back at it! Just ordered 2 more laptop batteries. Apparently theyre genuine laptop batteries but I’m a tad skeptical for good reasons. I think they’re either 9 or 12 cell batteries. I’m planning on making a 7S 19.5v laptop power supply for my Dell xps. I’ve confirmed my cc cv buck converter should handle the power load for the laptop so I’m quite excited about this project! Will keep you guys updated when I get the laptop batteries.

Cool. I was going to build a pack for my MacBook Pro, but then it died, and the replacement uses USB-C + USB PD for power, which on the one hand, opens up lots of options, but on the other hand, requires smarter circuitry.

YZX had some boards that provides USB PD from any DC input, but they are a bit spendy, so I just bought a 30W RavPower USB-PD power bank. I have a couple of 27W USB-PD car chargers. I originally planned to use the guts of one of them for a battery pack.

If you build a laptop pack, you might want to look into skipping the buck converter all together. A lot of laptops seem to support a range of input voltages. For example, big high-wattage chargers may be 19.5v, while a lower wattage, compact, portable charger might be 16 or 14v. Check the specs on the options for your Dell to get an idea of what is possible. It could be simpler, but also, potentially, more efficient. Once you have the pack built, it would be worth comparing runtime with and without the buck converter.

I’m curious. How are you interconnecting connecting the cells for your packs.

I need the buck converter because I need to ensure I’m running proper voltage and the laptop detects it as a genuine charger. I thought about doing a usb C but realized 60-100w on a USB c pin out is probably not the best idea. A standard charger cord is much safer. This should easily double or even triple my battery capacity compared to my stock laptop battery.

I also want to use 18650 holders in a case rather than solder everything together. That will allow me to use the cells for anything else if I want to

Oh…lol If I remember correctly on lower wattage power supplies it’ll keep the battery at the same level…so if it maintains the same level without charging great…but we shall see…

Cracked open the asus batteries. I couldn’t believe it. A 12 cell battery for $10 on ebay…that’s actually genuine… Authentic LGD 18650 S3 cells! 2200mAh, nothing to write home about but better than some Chinese knockoff cells…

They’re these cells: Test of LG 18650 S3 2200mAh (Blue)

Unfortunately the power delivery isn’t too high but should be high enough to supply my laptop. 7S2P

I ordered 18650 holders so I can remove each cell if need be. I’m going to beef up the springs and bus bars so resistance is kept to a minimum. Pretty amazed I got 24 cells for $20…lol. Every cell in the first pack is 3.60v even so pretty good. Should also make a nice addition to my Convoy C8!

Hmm… So maybe going this route isn’t the best idea. Maybe a more versatile use of these cells would be to get a 150w power inverter for ac power and use the standard dell charger? I could then go without a bms and use my cc cv buck converter for 12v output and then get an AC inverter… I could use my iMax b6 for charging and balance charging… That may work better…

For ~$25 it looks like you can get a 3rd party car charger for dell laptops.

Also, I’m not sure, but I think the 1-wire chip may be in the plug-end of the cable, rather than back in the charging brick. You might be able to to find a 3rd-party replacement cable with the proper coding, or, if not that, get a used, compatible dell brick (the PC recycler in my neck of the woods sells them for $5-10). Remove the stock cable to use with your battery pack, and then add binding posts or a new cable to the brick and use it to power other things.

Ok! THanks guys for the help! Change of direction! I just ordered a 150w power inverter, 4s bms and another 12cell battery. I’m going to make a portable powerwall basically. Essentially its going to be a big power bank but AC capable…and not just the puny power banks…this thing should be like 4S8P…. 32 cell power bank… Then I’ll easily be able to power my laptop and anything else. The only unfortunate consequence of this is it’ll be much larger than originally planned. But I’ll try to defeat that with an efficient heatsink which will allow for fanless operation.

Been testing a few of the LG 18650 S3 cells and they seem to hold around 2150mAh at 1A down to 2.8V. After that they rebound to like 3.35v and I can tap another 100ma out of them at.2A so that’s pretty good I think.

I should get my power inverter today and my last asus battery. I’m planning on building the entire power bank in a Plano storage box that has a hinged top so i can do any maintenance that’s needed to it. Its also clear which I plan to cover most of it in vinyl wrap so well see how that goes. Should be the perfect size case as it fits the 18650 stacked no problem! Should make a nice portable multi use charger for anything I need….laptop etc.

Edit: Got the 3rd laptop battery, power inverter and pieces of equipment that will make me famous some day…hehe jkjk but anyway… Testing out the inverter now. Running it on a 12V power supply rated for only 5A…so I’m running my laptop on it and charging my phone…not the safest thing in the world but yea, it works and doesn’t get hot too!

I should probably make a thread for this…which I will if I find time…doubtful but anyway. Wanted to update everyone on my progress. Finished my mobile power wall…(Need to come up with a better name for it)

Pulled 6 Sony US18650GR (I think G7 version 2400mAh) out of an Acer AS09A41 laptop battery.

Need some advice. First pull.

I pulled from a Dell that’s about 3 years old 6, ICR 18650-22H Samsung’s.

One was dead and the rest read 2-3.5v.

I put them to charge in my only two chargers one a Nitecore I2 charger and a EBL charger.

2 batteries charged up fine. 2 charged mostly then got quite hot(not untouchable), so I pulled those off to cool. The other wasn’t charging quite right.

Let them set for a couple of days, checked the voltage and they all came down about .30 volts over a couple of days.

I then put them on the Chargers a couple more time and they eventually dropped less and less.

Most recent charge, all 5 even the two that got warm are now charging, cool, show 4.20 volt and are holding that like a new battery would.

Is this normal? Do 18650 pulled batteries need to be conditioned? Charged, charged, charged again until they are back to life. I have searched but couldn’t find the answer I was looking for. Or trash the ones that got warm.

Thanks.

Couple weeks back j found the same exact pack. 2 cells were dead the other 4 still tested over 2400. It seems with laptop packs it’s hit and miss abd it’s always surprises me. I’ll find packs 5 6 years old in the recycle bins and test at or near full capacity. And others just a couple years old complelty trashed mah wise

If they got unreasonably hot during charging. More then your normal temp for your charger enough that you stopped the charge then Ya I would recycle them. And keep the others. No need to take risks the bins will have plenty of 18650s for years to come to scavenge through. I hit my local Lowe’s up once a week. I use to work there so they let me dig through it. Home Depot Bogart’s the bin like your trying to steal something. It’s gotten to the point I don’t even care. When they say something I just walk out with the packs. They can’t do anything. And only loss prevention has the ability to really do anything. And they are only focused on keeping the merchandise from being stolen not recycled materials.