18650 from laptop battery

[smopoim86]

I have a battery from a gateway that was bad brand new. Instead of swapping it, they just sent an extra. There were 9 CGR 18650 E cells (should be Panasonic 2600mah).

After breaking the pack apart, 6 of the cells read 3.9v and 3 read less than 1v. They were in a 3s3p configuration. I'm pretty sure the control board had a problem that killed the pack.

The 3 batteries reading .98 volts are trash, correct? The voltage is low enough that they are permanently damaged.

Is there any charger that I can trust to charge these batteries without constantly monitoring them? or do I need to just buy a li-ion charger chip and build my own. Both chargers I have overcharge (hit the battery protection circuit) one is the Ultrafire 139.


I'm pretty sure i'm right on the low voltage cells being trash, and my best bet on a charger is going to be either a hobby charger or building my own.

Daniel

 

[csshih]

trash the 1v cells.

you should be able to charge the batteries in the 139.... that's what I do.

 

[kramer5150]

yes the 1V cells are toast, toss em' in the recycle bin. the other cells should work just fine. Although depending on the resistance of each cell, you will have varying degrees of success delivering power with currents over ~1.5A.

 

[smopoim86]

yes the 1V cells are toast, toss em' in the recycle bin. the other cells should work just fine. Although depending on the resistance of each cell, you will have varying degrees of success delivering power with currents over ~1.5A.

Are the panasonic cells not good at carrying much of a load? I figured they would be fine up to 1C.

 

[lolzertank]

Are the panasonic cells not good at carrying much of a load? I figured they would be fine up to 1C.

IMO, the 6 good cells are probably fine at 1C loads. Since 3 cells were destroyed, it sounds like one balancing channel in the control circuits somehow malfunctioned.

 

[Mjolnir]

I have over a dozen salvaged laptop cells that I charge with my PILA IBC, and it always terminates the charge at the same voltage, unlike another cheaper charger I have (the DSD). If you get the PILA, you should be relatively safe.

 

[lolzertank]

I have sku.6105 from DX. It works perfectly, following the CCCV charge algorithm well. One channel has a open circuit voltage of 4.2V and the other is 4.21V. Not a big deal, only 10mV. A lot cheaper than the PILA too. Just get a DMM and your finger thermometer and be sure to check it every few minutes.

 

[Moddoo]

My panasonic CGR cells are the best out of a few different brand salvaged cells I have.

They are the only ones that will deliver 2.5A+

Take care of them and enjoy the free lumens!

 

[tedshred]

My work tosses laptop packs into the recycle bin every month or so, and I pull them out. Usually, the pack is tossed because one or more cells have gone bad for a variety of reasons and the pack no longer takes a charge. I carefully disassemble the pack, check each cell, charge the ones above 2.5v, and recheck them 20 minutes after rest, 24 hours after rest. If they hold better than 85% I keep em and recycle the duds.

Sometimes the tossed laptop battery packs at work have prismatic LI-ion cells which also work well but pack a slightly weaker punch and runtime.

Always monitor the charging of these unknown source/history batteries for the first few charge cycles so you know the batteries characteristics. Also, some of the batteries become unprotected once they are removed from the pack circuitry.

 

[vali]

Also, some of the batteries become unprotected once they are removed from the pack circuitry.

You mean the rest of them are protected? I allways thought the protection circuit was allways in the battery case, not in every cell.

 

[csshih]

The protection circuit is in the battery case. you can see a long PCB off to one side.

 

[RGB_LED]

You mean like these? :naughty:

I picked up a few of these cells for $0.50 at a local electronics surplus store in '08; a couple of them were DOA but these 5 have served me quite well for the last year. I've even powered a P7 drop-in in my SF 6P with these cells... I just measured it with my DDM and it's pulling about 1.6A.

Recently, one of the CGR18650HGL (purple) cells no longer held a charge so I recycled that one. But they charge fine with my WF139 but... I do tend to watch it like a hawk since I don't want it to go .

If you want to be absolutely sure that you will not overcharge them, then - as suggested - the Pila IBC is the way to go.

 

[Moddoo]

You mean like these? :naughty:

I picked up a few of these cells for $0.50 at a local electronics surplus store in '08; a couple of them were DOA but these 5 have served me quite well for the last year. I've even powered a P7 drop-in in my SF 6P with these cells... I just measured it with my DDM and it's pulling about 1.6A.

Recently, one of the CGR18650HGL (purple) cells no longer held a charge so I recycled that one. But they charge fine with my WF139 but... I do tend to watch it like a hawk since I don't want it to go .

If you want to be absolutely sure that you will not overcharge them, then - as suggested - the Pila IBC is the way to go.

Nice deal on those!

Mine are the blue "C" model. Each one has been through about a dozen cycles, and seem to be holding up well.

of course, they take a little extra care, but great cells IMO.

On one of my triples w/2.8A driver

 

[Search]

So I could break open the battery pack of an old laptop and salvage 1 or 2 18650 batteries :O

Well, the ones that have those in them.

This is great, now I need a battery tester, a charger, and some balls.

 

[Moddoo]

I have to add a disclaimer in case anyone that sees this is unaware.

LITHIUM CELLS CAN EXPLODE, POISON/KILL YOU, AND BURN DOWN YOUR HOUSE IF MISTREATED

please do your research completely before messing with any lithium cells.

A short circuit can easily happen while disassembling a laptop pack.

be careful

 

[Mjolnir]

I had 2 packs full of the GCR cells, but unfortunately none of them were in good enough condition to use (one pack didn't read a voltage at all...). They were probably too old.

 

[RGB_LED]

I have to add a disclaimer in case anyone that sees this is unaware.
LITHIUM CELLS CAN EXPLODE, POISON/KILL YOU, AND BURN DOWN YOUR HOUSE IF MISTREATED

Moddoo, thanks for the added warning... you are right, we all need to be constantly reminded of this. Luckily, I purchased my Li-ion's individually and not as part of a laptop battery setup. Still, I have realized that they can be deadly so I constantly remind myself to be extra vigilant and I am also in the process of looking into purchasing an IBC charger to add an extra layer of safety.

 

[tedshred]

Yes, use extreme caution when prying open those laptop battery packs. They use a lot of glue to hold the shell together, and if you are not careful, your screwdriver can cause real damage to the cells and danger to you. I like to place the pack in a table vice and slowly squeeze the case at one end until I can get just the tip of my screwdriver in. Then I use another screwdriver to work my way around until I can get a firm grip on the case parts and with both hands and slowly pry the case open. Be sure to watch what your doing and not tear at it like a gorilla. If you see the PCB board, move to the other side where the PCB is not. Do not tear the plastic shrink wrap of the cells.

 

[bshanahan14rulz]

also, do not deform the arrangement of cells. You are more likely to cause unnoticed shorts if you have a big web of cells. Sure would suck if one battery vented, popped, and set off some sorta chain reaction

 

[csshih]

So I could break open the battery pack of an old laptop and salvage 1 or 2 18650 batteries :O

Well, the ones that have those in them.

This is great, now I need a battery tester, a charger, and some balls.

they have around 6-8, I'd say.

hey!
I have some of those labeled panasonics! they're yellow!