Tutorial: Laptop Battery Pack 18650 Extraction

[Kilted]

I bought the Pila charger and have had no issues at all so far. I use it for both the salvaged unprotected 18650s and for the protected 14500s I use in my Quark and LF5XT.

I'm still a bit paranoid, though. When I charge my cells, I put the charger in an open ammo can that sits on top of a granite counter near the back door. If something goes wrong, I can grab the can and throw it out the door.

Also, I only use my cells in lights that have over discharge protection (L-mini and PLI) and even then, I never run my cells below 3.7v.

--flatline

Flatline,

I have the older Pila BC2 charger. It's output is listed as 4.6v DC. From everything I read this would overcharge an unprotected cell.

I suspect this charger depended on the protection circuit to end the charge.

Any thoughts?

Thank you =D~~ Kilted

 

[alfreddajero]

The Maha C777 doesnt charge lithiums only nimh and nicads.

 

[Kilted]

The Maha C777 doesnt charge lithiums only nimh and nicads.

Funny you should say that, then how come;

http://www.mahaenergy.com/store/viewItem.asp?idProduct=185&cur=specs#mid

Chemistry Supported:
Lithium Ion, Nickel Metal Hydride, Nickel Cadmium

spec sheet says it does and there is a nickel/lithium switch on my unit.

=D~~ Kilted

 

[rufusbduck]

I just pulled a bunch of these, but scuffed the wrapper of a few. The shrink wrap is incredibly thin and delicate. Can anyone think of a way to repair the wrapper?

You can buy heat shrink tubing from dx, kd, or local electronics store. Cut pieces ~ 1/4" longer than the cells and carefully heat with small torch, match, etc. It's actually a good way to make up multicell packs after you have soldered the taps.

 

[alfreddajero]

Well if you had told us which version you had then maybe just maybe i would have done a proper search.....lol. Give us the right info so we can get it straight.

 

[flatline]

Flatline,

I have the older Pila BC2 charger. It's output is listed as 4.6v DC. From everything I read this would overcharge an unprotected cell.

I suspect this charger depended on the protection circuit to end the charge.

Any thoughts?

Thank you =D~~ Kilted

It's my understanding that the earlier Pila chargers (don't know the models, but perhaps your's is one) depended on the protection circuitry of the battery to cut off properly. If you suspect you might have one of those chargers, don't use it with unprotected cells.

Actually, I'd recommend you don't use it at all just in case you have a cell with faulty protection.

--flatline

 

[Kilted]

It's my understanding that the earlier Pila chargers (don't know the models, but perhaps your's is one) depended on the protection circuitry of the battery to cut off properly. If you suspect you might have one of those chargers, don't use it with unprotected cells.

Actually, I'd recommend you don't use it at all just in case you have a cell with faulty protection.

--flatline

Flatline,

Thank you thats what I wanted to know.

 

[Kilted]

It's my understanding that the earlier Pila chargers (don't know the models, but perhaps your's is one) depended on the protection circuitry of the battery to cut off properly. If you suspect you might have one of those chargers, don't use it with unprotected cells.

Actually, I'd recommend you don't use it at all just in case you have a cell with faulty protection.

--flatline

Flatline,

I am putting Fenix TA21 kit for my brother. I brought a new Pila IBC charger for him. So I tried it, I like it and will order one for me.

Thanks for the suggestion. I did not know the Pila charger could charge unprotected 18650's.

=D~~ Kilted

 

[l_____l]

I happened to see a post on Craigslist in the FREE section for computer parts and printers on the curb...come get what ya want, and found a dozen laptop batteries! I've opened up 3 packs so far...1st one, all cells 0.00V! 2nd, found 2 18650's at 3.60V, the 3rd pack was for a Dell, 14.8V at 4460mAh of which ALL 8 cells were between 3.58V and 3.69V!! These are the Sony Fukushima US18650GR (G5 version).

When tearing down Li-Ion packs, keep them in parallel pairs at first. Test the pairs for voltage, then separate one end and test again to see if they are exactly the same voltage! Mark them as P1 (for pair one as an example). That way you know you have a "pair" that is good to use in other applications, such as bike lights, and that pair is still "matched". If you find a "pair" that one is 3.59V and the 2nd in the "pair" is 2.49V, you know to properly dispose of the 2.49V cell!

As for chargers, I have a TrustFire TR-001 that works well for me. I also have a Tenergy Smart Charger http://www.tenergybattery.com/index...facturer_id=0&option=com_virtuemart&Itemid=27

This has a switch for 3.7v,7.4v,11.1v and 14.8v. Like the TR-001, it has a 500mA output. I am kicking myself for selling my MAHA 777Plus, as that was the best charger I ever had, and...now discontinued!

I'm now looking at the Tenergy Micro-Controlled Li-Po/Li-ion Balance Charger w/ LCD Display (Item Number: 01200) See: http://www.tenergybattery.com/index...facturer_id=0&option=com_virtuemart&Itemid=27

But, for most, this may be overkill!

I enjoyed the thread,

-Pace

 

[csshih]

stay safe and have fun!

 

[rockz4532]

Thanks a ton for the tutorial. I found a "bad" dell pack to take apart. It took me around an hour to extract the cells. I didn't want to risk anything happening, so the hour was long and I was when something slipped. Luckily, nothing bad happened. Now i have pink samsung cells, marked ICR-18650-26A with SD1 and 654 below it. I measured all 6 cells, they were all at a healthy 4.15v, so much for "bad".
Can someone experianced with batteries verify if these cells are good? I hooked up the 18650s to a 1 amp load and all of the cells dropped from 4.15 to around 3.9-3.95. Is that good?

Currently I'm letting the cells sit for a week to see if theres some un-normal voltage drop.

One last thing, does anyone know how to get rid of the 4 sharp prongs on the terminals without a dremel? I don't have one and it seems pretty risky with a dremel...

 

[l_____l]

Thanks a ton for the tutorial. I found a "bad" dell pack to take apart. It took me around an hour to extract the cells. I didn't want to risk anything happening, so the hour was long and I was when something slipped. Luckily, nothing bad happened. Now i have pink samsung cells, marked ICR-18650-26A with SD1 and 654 below it. I measured all 6 cells, they were all at a healthy 4.15v, so much for "bad".
Can someone experianced with batteries verify if these cells are good? I hooked up the 18650s to a 1 amp load and all of the cells dropped from 4.15 to around 3.9-3.95. Is that good?

Currently I'm letting the cells sit for a week to see if theres some un-normal voltage drop.

One last thing, does anyone know how to get rid of the 4 sharp prongs on the terminals without a dremel? I don't have one and it seems pretty risky with a dremel...

Geezzeee....First time rippin Li-Ion packs apart? ??

18650 cells are the rule in "most" laptop battery packs. Often times, it's one cell that fails, or the circuit board that has failed.

In any event, the "pack" is void. (Singel cell separation) !

Li-Ion battery "packs" are created to provide up to 14.8V for portable devices. A single cell is rated at 4.2V, and "dead" at 3.5V.

So, what happened? Are you trying to power an automobile? Probably not, nonetheless, "most" defective laptop battery packs are due to users who have no clue as to recharging Lithium Ion batteries.

Be safe, for LiFEp04 is not yet being used in cell phones!

Use "google.com" to learn!

 

[rockz4532]

I know about 18650s. I want to know what kind of voltages under load are acceptable.

Also, if anyone knows, how should I discharge test the cells to see how well they match up to the 2600 mAh capacity? My charger has a discharge function that goes from .1-1.0 Amps and has a programmable voltage cutoff.

 

[Egsise]

Nice pictures!

I use WF-139 to charge my unprotected Li-ions.
The problem is, there are very few 18650 lights that have built in overdischarge and reverse polarity protection.
MG PLI MC-E warm white has one, it doesn't cut off at 2,8V but it starts to flash.
The new MG flashlights has this feature too because the circuit is the same.

 

[etc]

I do the same thing. I use single 18650 in a FiveMega body with Malkoff M60L and it works nicely. With unprotected cells, you can really tell when they dip below 3.7V, visually.

 

[xamindar]

Has anyone come across 3.6v cells? When I initially tried charging one 18650 cell from a laptop battery pack it got very hot when the voltage got above 4.10v on the charger. I then switched the charger from the 3.7v li-ion to the 3.6v li-ion setting and the batteries all charged to the end without getting warm. Is it just possible these batteries are bad? Or is it possible some made were of the 3.6v kind instead of 3.7?

The charger reported very close to 1300mah when it finished each one. I have not tried to cycle them yet.

 

[koala]

Before you go salvage your cells, ripping the welded tabs off can cause micro-puncture on Sony cells. I don't know what is the result of using a punctured cell and I don't know how other cells are made. I punctured a cell when pulling the tabs many years ago. So inspect the surface of the negative contact before use.

 

[LuxLuthor]

I know about 18650s. I want to know what kind of voltages under load are acceptable.

Also, if anyone knows, how should I discharge test the cells to see how well they match up to the 2600 mAh capacity? My charger has a discharge function that goes from .1-1.0 Amps and has a programmable voltage cutoff.

Before you go salvage your cells, ripping the welded tabs off can cause micro-puncture on Sony cells. I don't know what is the result of using a punctured cell and I don't know how other cells are made. I punctured a cell when pulling the tabs many years ago. So inspect the surface of the negative contact before use.

So have I, but didn't realize it until sanding off the weld burrs with my Dremel sander. That was the only close call I have had, but I'm hyper-safety conscious doing things like this, checking voltages out the wazoo, and always doing most work with Lithium cells either outside, or in the garage so if there is a venting, I drop on concrete, or metal pail of sand, push the garage opener button to vent as I'm running inside.

 

[flatline]

I've never bothered to remove the welded on tabs when I salvage cells. I just trim the tabs down with a diagonal cutter and smooth the edges so that I don't cut myself on them later.

Besides aesthetics, is there a reason to actually remove the tin(?) tabs welded to the cells in a laptop pack?

--flatline

 

[lemlux]

After I twist off the main part of the negative end tab with needle nose pliers I deal with the the four sharp tig-weld prongs by gently tapping the battery on a tempered glass surface. The result is an uneven but not sharp surface.

As for the tabs on top, I usually leave enough material so that I can double, triple or quadruple fold the tab remnant to make a quasi button. I then tap this end on tempered glass as well until the surface is smooth to the touch. Accordingly, on most lights except those with the smallest diameter recesses for anode contact I can avoid having to use a small magnet to make contact.