Opened up a bunch of never used laptop batteries! Every battery had 1.5v! Help!

Batteries and Chargers Rechargeable Batteries
1

First post, long time lurker, etc… Have a large collection of flashlights already including single 14500, dual 18650, single 18650, HID, etc…

So we recently refreshed all of our laptops at the company I work for and we decided to go with a different make with the new ones. The bonus for me is, we have a stack of shiny new dell batteries that we keep on hand for people that have old batteries or have batteries go bad. So once we got done rolling out all the new laptops, I took all the never opened dell batteries home to rip open and check out the 18650’s inside them.

Now I have taken these exact same batteries apart before and used the 18650’s out of them and never experienced any weirdness. However I have only opened previously used batteries before. In other words batteries that have been charge at least once previously with a laptop.

These batteries are still sealed from dell and have never been in a laptop since we received them. They are all probably 3 years old.

So once I ripped apart one of them I measured the batteries with a good multimeter and got 1.5v on all of them. Now the prevailing opinion on the forums seems to be that you should never try using these unless they initiallly measure at 2 volts or better, with some saying 2.5 or better.

Knowing this I figured I just opened a bad battery and thought wow glad we didn’t give that out to someone ever. Then I opened another one. Same exact thing all batteries measured 1.5v. The next 3 batteries that I opened were identical. So I then took one of these batteries and put it in an old laptop and after charging for a few hours seems to be a great condition new battery. I then open this battery up and measure the 18650’s I take out and get 4.1 volts…

So now I wonder could the very low voltage on all of these batteries be just because they have never been charged and sat in our data center for a year or two? Once in a laptop they seem to work perfectly and perform like a new battery.

Can I attempt to charge these with my v2 intelligent charger or should I charge them all in a laptop first and then open them up? Or do you guys think they are indeed bad?

2

Charge them in the laptop first. The laptop is much more sophisticated and if there is a problem will shutdown. The other problem is the I4 may think they are Nimh because of the low voltage.

3

I would to charge them in laptop first! But after 2 years of waiting and not being used it is possible that their capacity is reduced (significantly).
I would go through the process of charging and discharging in laptop at least 2 times…

4

Welcome to the BLF Sylk

I hope you have as much fun here as I do ;-)

Good point about the Nimh in the I4 charger Scaru. And I totally concur on all points of your post.

@ OP:

The ones you have already opened will have to be either discarded or charged in a Li-ion only charger.

It is of course up to you to decide if you want to do this or not since it sounds like you have a whole lot of batteries on your hands even without the ones you already opened :-) What a sweet score. Congratulations on that.

5

I am NO battery expert. Were all the batts a uniform 1.5 volts? I seem to remember that they are now in sleep mode at that point. Of course now I can’t find a single mention of it online. Uggfhhhh.

They may be too low for some chargers to recharge, BUT they MAY be still fine. They also may be worthless — or dangerous.

If you charge them in a li-ion only charger for like 2 minutes or so, in my experience (which isn’t necessarily everyone’s experience and also may NOT be safe), they should pop up to a better voltage, maybe 3 volts if you are lucky. Just a couple minutes “wakes” them up. I don’t know how this “sleep” level works, only that it does appear to work in SOME lowish batteries I have tried. I then continue to charge normally, observing all the usual cautions. If they don’t pop back to 3 volts or so, I toss ’em.

But then this guy says NEVER to recharge batts at that 1.5 volt level if they have been there for a week:

“Do not recharge lithium-ion if a cell has stayed at or below 1.5V for more than a week. Copper shunts may have formed inside the cells that can lead to a partial or total electrical short. If recharged, the cells might become unstable, causing excessive heat or showing other anomalies. Li-ion packs that have been under stress are more sensitive to mechanical abuse, such as vibration, dropping and exposure to heat.”

So he’s saying — even if they appear to charge fine — they could short internally at some time and do the dreaded “vent with flame” deal with NO user intervention , i.e., the li-ion battery just vents by itself sitting on a shelf. And since we can’t see inside to see these shunts, we don’t really know if the cells are no good. There is always the chance of an internal short and an explosion. A small chance, but it’s there. There was a NASA report about this. Hmmm. Where is it? Here:

As I remember, NASA seems to say something slightly different: They seem to imply that single over-discharged cells won’t get the wonkiness, but cells will get wonky in some cells over-discharged in a series array, like a laptop pack. And NASA blew up plenty of 18650s in their research.

I think laptop pulls are the way to go. I use them extensively. But once again, please be careful. You can short cells in a pack just ripping the pack apart. While you’re trying to get the batts out, a couple could be overheating from a hard short and ready to blow. There often isn’t anything more than a piece of flimsy nonstick masking tape protecting the plus terminals in those packs. It’s really easy to shift wires; snap a PCB or move the tape and now you have a completed circuit. Cells are in a hard short, and it’s just a matter of time before stuff overheats and kablooey.

I think there is a primer on disassembling packs either here, on CPF or maybe just on the web.

Please double-check anything I am saying. Read about li-ion safety and then read some more. There is a lot of conflicting info, so it’s difficult to know exactly what’s the gospel or what is baloney.

6

Yes every battery I’ve pulled so far was at 1.5 which is another reason I’m a little suspicious that they are all not bad. Usually when I have pulled bad batteries I get varying voltages. Though those are usually well used bad batteries…

Anyway I’m going to charge the rest of them up in laptops and then take them apart.

Then ones that I have already removed I am going to try charging in on my workbench with me watching the voltage to see how it goes.

Thanks for the replies!

7

Ubehehe, what you are thinking of is that the protection tripped, that will give a voltage of 0. However that is not the case as these are unprotected. What happened is the Cells were discharged by the protection circuit in the battery pack and all were discharged evenly. Since you have so many batteries I would just toss those ones.

8

A few years ago I bought a neat little Li ion powered cordless drill. It’s 10.8 Volts and really small, lightweight and powerful. Except now some of the cells have died, but I digress.

The instructions for first charging the battery packs were something along these lines:

1. That the packs are only partially charged from the factory with a storage charge and not suitable to be used until fully charged on the supplied charger.

2. The packs were capable of being stored indefinitely with the factory storage charge.

3. Once charged the packs would gradually lose charge after several months and therefore must be monitored to maintain the correct voltage and topped up regularly.

4. Once charged the pack is no longer capable of indefinite storage as the internal circuit switches from storage to usage mode and this cannot be reversed.

Perhaps the laptop packs you have are similar? I can’t say for sure that is the case, but it sounds plausible. However, please be careful, much better safe than sorry.

9

You're going to love it here, Sylk!