# Are these 18650 cells protected?



## GilmoreD (Jan 19, 2008)

I have old cells out of laptop batter packs. One is a blue cased Sony, number US18650S. This has the feel of a metal strip on the side, and I'm wondering if it has a protection circuit in it. 

The next is a green cased Sony, number US18650GR. It feels like it has a metal strip as well. 

Are either / both of these protected? 
I have a WF139 charger and a charger that only charges to 4.2V, so it's great for unprotected cells. 

Thanks in advance for your help.
Dave


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## 65535 (Jan 19, 2008)

Pics.


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## LuxLuthor (Jan 19, 2008)

I'm guessing that is a label overlap you are feeling. They usually put the protection/balancing circuit in the pack, rather than like AW & Pila do in each cell...but yeah pix would help from different angles. Look at my thread where I took apart protected batteries to see what that looks like.


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## DUQ (Jan 19, 2008)

I have the exact same cells and they are *NOT* protected cells. I use them in all of my LED lights but not in my incans. The balance/protection circuit is built into the pack. You would have seen it when you broke the pack apart.


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## HunkaBurninLove (Feb 6, 2008)

Sorry to threadjack, GilmoreD, but I didn't want to start a new thread because I have a similar question. I also just found 8 similar batteries in an old Mac Powerbook G4 laptop batterypack: green labeling, Sony/Fukushima name on the side:

















I'm new to the rechargeable game but I don't think these are protected cells because it looked like the safety circuit was in the plastic housing that I destroyed 

Luckily, they read 3.43-3.58V so I wonder if it's OK to use a WF-139 charger to see if they can be brought back to life? 

I know to remove the batteries when the charger light turns green, but is there any harm to use these unprotected cells in my flashlights?

I searched and found  this thread and think it's OK to use but I just want to make sure


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## LuxLuthor (Feb 6, 2008)

These look like the Sony/Konion cells I described here. What is the part number on your cells? Don't assume anything until you identify that cell number. They are likely Lithium Cobalt cells.


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## mdocod (Feb 6, 2008)

Hello Hunkaburninglove,

The voltage on those cells indicates that they were probably stored away in a near-dead state. They are, in my opinion, safe to charge up and see if they work, but they will probably not work great anymore. If they have been sitting at ~3.5V for awhile, then they may be shot. Check the voltage after pulling them from the charger, then check again after like 20 minutes of resting or so, if they will hold above 4.0V then you should be able to get some safe use out of them, if they drop to ~4.0V or below within a few minutes of charging you may want to discard them.


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## HunkaBurninLove (Feb 6, 2008)

LuxLuthor: the part number was like GilmoreD (Sony Fukushima STG, US18650GR, with a "G5" beneath that striped line).

mdocod: Yesterday I charged one of them and it was 4.13V off the WF-139. Today the voltage is 4.10V so it looks like it held its charge. I'm charging another pair and will use your pass/fail guidelines.

Any other things I should look out for?


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## mdocod (Feb 6, 2008)

heat, if they are getting really warm while charging or taking a really long time to terminate the charge (long than they should). Slightly warm seems to be normal on chargers like the WF-139. Sounds like they are going to work ok to me... You might do a runtime test on a few in a controlled situation (constant current or close to it if you can). Making sure they are delivering something in the ballpark of label capacity, if they even have a label capacity.


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## Probedude (Feb 6, 2008)

I've found the same cells in a Dell laptop battery pack that's many years old. Going to charge one up this weekend and take some measurements.


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## HunkaBurninLove (Feb 7, 2008)

Heat seems to be OK while charging (warm, not hot). I'm making sure to be around when charging these cells.

Took about 5 hours to charge this last pair (4.12 and 4.11V off the charger, and the same reading about 35 minutes later).

I'm expecting a Dereelight in the next several days to do some runtime tests.


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## LEDite (Feb 7, 2008)

Dave;

The Sony cells have a PTC and a pressure disconnect for high current.

They are not "protected" against high voltage.

By the way, those are 2200mah cells and their age is 1.5-2 years.

Larry


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## warx23 (Mar 8, 2008)

I ran across this thread while trying to gather info about these cells (sony us18650gr). Not trying to thread jack but I think my question might be relevant. 

I have a bunch of dell battery packs laying around to use as donors. I will disassemble them and see if they will hold a charge or are dead.
I'm new to this scene and am gathering parts to build a ROP (lithium edition - 2c mag donor with 2x18650's) like this one http://lights.lightrefineries.org/?page_id=35

Can I use these sony cells and this charger? http://www.dealextreme.com/details.dx/sku.6105
Thanks!


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