are revived batteries "safe"?

[Vesh]

Hi there, about 10 of my vtc5a's have drained to like 0.3 to 0.8 volts over the last few weeks, sitting inside my smok and sigelei mods.. I already knew about this in my yihis and leave those 2 empty now. Because of this, i checked everything else today, and they are all at the exact level i left them (dna's/joyetechs/others).

So obviously besides yihi, smok and sigelei drain the batteries and don't stop, even when mods are completely shut off).

The batteries have taken hours to charge but all revived in my xtar and opus chargers. The xtar confused a couple of them as ni-mh and stopped at like 1.6 volts, but removing them and putting them back in fixed this.

What i want to know is if batteries that have been drained so low and revived, are safe to use at their normal rated CDR. That's it, basically!

I am taking more care in the future and will be storing all batteries externally in cases at 3.8 volts except for say 4 mods i am using in rotation where i will keep them in, and so on.

I very much appreciate your help as always..

regards
V

 

[Heartsdelight]

Following

 

[Mooch]

Safe? No.
Inherently dangerous? We don't know.

At below 2.0V or so the copper electrode inside some li-ion batteries literally starts to dissolve. When the battery is recharged this free copper starts to plate itself onto places in the battery that should not become conductive. There is a possibility of a short-circuit.

There's no way to reliably predict what will happen and when but the longer they are at a low voltage the worse the situation becomes. While they might be just a bit damaged I always recommend replacing batteries that have dropped that low. It's just not worth the risk.

 

[Vesh]

an expensive lesson learned.. thank you Mooch.. that's $150 worth of batteries for the bin. Oh well.

 

[Barkuti]

It depends on the amount of time the batteries have gone through over-discharged (below ≈2V as Mooch pinpointed), in your case means get them to a recycling depot.
I once had a couple in series cells go down to 1.5 and 1.8V during a 2S torch driver test which obviously didn't have any kind of low voltage warning or protection. I immediately recharged them, no problems arose but of course there was nearly no time for any under-voltage degradation to occur in a handful of minutes.
An NCR18650B blew up on the charger of a fellow who dared to relive and recharge a cell who had dwelled on a drawer at 0V for an undetermined amount of time. Boldness and ignorance makes no good recipe.
When in doubt, toss them away (at a recycling depot of course).

On the positive side, you can now grab a multi-pack and save on cost per cell, and/or try other cells also.

Cheers

 

[Vesh]

Thanks also Barkuti.

i really extra screwed up.. I also, at the same time, took batteries out of the mods that i noticed were draining.. for example a couple weeks ago i had 4 charged batteries in my snowwolf 365 (my fave four battery mod by the way, the only thing of sigelei's i really like) and i noticed they were low on the sigelei meter (but device still turned on and functioned).. hence.. they were draining while device was off but not at an unsafe low voltage yet...

I had my 3 chargers going at the same time, and i have confused which vtc5'as were in that snowwolf for example to the ones that had drained completely to 0.3 volts in my smok G320...

There is obviously nothing wrong with the ones from the snowwolf and they were new batts.. All i have to do is charge them and put them away..

well guess what, i can't tell the difference now, so i'll have to also throw out perfectly good batteries.

Is there ANY sort of test out there that I can do to see which are which? Note to self.. label batteries from now on.. reason i never had labelled is because i always kept them inside mods and just charged as needed for mod.
#idiot (bangs head against wall)

VTC5a's are $13 EACH here, yes, for one battery. I have 9 good batteries from various mods, that were draining but no where near under 3 volts yet and I don't know which ones they were, vs the ones that were totally dead. 9 batteries is over $100 wastage. But of GOOD batteries. This totally sucks.

I can only blame myself, but i had to just say what a dick move that was on my part!

If anyone is not frightened and wants all the batteries, eve the ones that had almost dropped to zero all activated and charged fine, if you are in oz you are welcome to all of them free, just drop me a PM. There's like 17 batteries all up or something. Most 5a's, a couple 4s, and aspire 1800's.

Mooch has made me too paranoid to keep. Probably my OCD doesn't help either (clinical, real ocd unfortunately.).

 

[Vesh]

It depends on the amount of time the batteries have gone through over-discharged (below ≈2V as Mooch pinpointed), in your case means get them to a recycling depot.
I once had a couple in series cells go down to 1.5 and 1.8V during a 2S torch driver test which obviously didn't have any kind of low voltage warning or protection. I immediately recharged them, no problems arose but of course there was nearly no time for any under-voltage degradation to occur in a handful of minutes.
An NCR18650B blew up on the charger of a fellow who dared to relive and recharge a cell who had dwelled on a drawer at 0V for an undetermined amount of time. Boldness and ignorance makes no good recipe.
When in doubt, toss them away (at a recycling depot of course).

On the positive side, you can now grab a multi-pack and save on cost per cell, and/or try other cells also.

Cheers

it's only ever happened once to any of the batteries it has happened to, but it could have been weeks that they've been sitting in the mod discharged.. you see i have tended to use 2 specific mods the last few weeks and didn't think to check others.. I only thought of doing it for some reason yesterday.

What gets me is my stupidity in not separating to a different charger, or marking, the batteries that were not under voltage but just needed a charge cause the mod was draining them anyway. I still can't believe how stupid that was of me.

NO batteries had an issue charging and activating - the three chargers uses were a Luc6, an opus 3100 2.2 and an Xtar Dragon VP4.. does the fact none brought up an error message mean anything?

Also, on a few of them, they jumped from say 0.8 volts, to 3.0 volts within about 2 minutes, if that means anything.

 

[Barkuti]

Bummer it really is to discover how a piss poor device can ruin your cells because of parasitic drain. Is your Smok G320 damaged? Any other documented user complains with such mod? Certainly disturbing.
I am afraid there's no reasonable way to discern the over-discharged cells from the "good" ones, they may have lost some capacity and discharge performance but, since you have no track of the prior to mishap health condition of the cells…
If the cells really dwelled over-discharged for a long period, they may show a noticeable reduction in capacity, but there's no guarantee. Quite recently The Miller @ BLF reported a similar problem, pretty hopeless.

AliExpress has a good deal of nice sellers with quite good prices for cells. You may want to check it out and see if some cheap shipping option to where you live arises. Take a look at the product feedback and pretty much that's about it. The good thing with AliExpress versus eBay is the sellers don't see a dime until buyers confirm the product receipt, which along its pretty good dispute system makes it work really good and safe. Also, there's the 11-11 sale soon. The bad? Slow boat shipping.

Cheers

 

[Vesh]

pretty much no one OS ships lion batteries to oz anymore, seriously. Australia post are making it hard to even ship within australia.
If the G320 was damaged, then so would be my alien, my H priv, my snowwolf 365 (which i caught in time), my fuchai duo, my yihi Q, my yihi G, my minikin 2, my ocular touch and my g priv LOL. i highly doubt it, since all checked out as authentic..
those are the affected devices.

I have been researching and apparently the resistance changes... i noticed that on the 2 sets of sony vtc5A where i don't know which were the good or bad, that one set of them reads a higher resistance than the others, by about 20%, so i am *guessing* that they are the bad ones.. still, there is no way to be sure.

What can actually happen here.. explosions?

Do you know that to dispose of them properly, i have to take them to a battery store that does it, there is also nothing close by.. so i am not going to throw them in the bin, will just keep them here for now unless somebody wants them as said.
I called the closest battery world and it's a 40 minute drive! um. No. And i am not allowed to throw in recycle bin. Sigh.

 

[Vesh]

Ok I have been doing more research.. Mooch is my battery God and a fantastic person to boot, and also thank you Barkuti, but i just wanted to confirm elsewhere.. and the general consensus is not to use these to vape.

I will toss the good ones as well, not to take a risk. However, I will do a capacity test in the dragon, and if there is a stark difference in capacity, then I will be at least pretty sure which are the good vs bad.

It will take some time but I will start today, at 500ma charge/discharge setting.
I'd like to at least be able to tell the good triple vtc5A's from the bad set of three, i also did the same thing with a set of 2.. so 5x vtc5a's overall are definitely fine and i confused them when i charged and tested them all.

My face (and anyone's) is much more important than money, so I will also retract the offer to give them away, as i feel that i could therefore contribute to something dangerous for someone else, which i would never ever be a part of. Please understand it's my conscience here and your well being.

Anyway, i will report back on my capacity tests.. I am hoping the bad 3 come out at say 2200 mah and the good ones come out at say 2550 which is what I usually get on my vtc5a tests.. this will be enough for me to feel confident to keep the good ones. I will test a couple i KNOW are bad first ( i put them in a silicone case so i know which ones), they were drained to like 0.3, the lowest of all, and if they bring up a normal capacity, then I will know not to bother testing all the others. If they come up low, then i know it will be worth testing them all to determine good from bad! Cheers!

 

[Barkuti]

Wow!
If you're confident your internal resistance measurements are right and they entail the exact same number of affected cells, you have probably sorted it out.
My town has advertising stands with integrated battery bins, its less than a one minute walk for me.

Some sellers still ship to Australia:

• US18650 VTC5A 2600mah - Shop Cheap US18650 VTC5A 2600mah from China US18650 VTC5A 2600mah Suppliers at Turmera Battery&Charger Store on Aliexpress.com Price here isn't that good as it is but, next Saturday…
  
• 2pcs/lot New Genuine US18650VTC5A 18650 3.7V 2600mah VTC5A Rechargeable Battery Li ion Batteries For Sony Free Shipping-in Rechargeable Batteries from Consumer Electronics on Aliexpress.com | Alibaba Group

Cheers

 

[Vesh]

capacity tests showed nothing so far.. 30Q's affected came up as 3032 mah, and 2520 to 2550 for the vtc5A. I will still test the other set of VTC5A to compare.

The aspire 1800's did show a drop though to 1680 from 1811 ish. If anyone is interested.

 

[Barkuti]

Good, I'll probably have to end up biting the bullet with regards to the negligible effect of short-term overdischarge in battery capacity reduction.
However, go for internal resistance testing, Vesh. To discard the effect of contact resistance variation, please do a sufficiently large set of measurements for each cell, to finally obtain each average value. This may show a different perspective.

Cheers

 

[Vesh]

internal resistances are all the same as they were before.. sorry i thought i said that.. i did the inaccurate test in the opus cause it's so easy to do.. but *relatively* it still counts that the figures are identical to when i did them say in May (i jotted them all down and posted them here also to Mooch to ask if was normal).

However, then using my vp dragon and it's probes, i got normal low resistances expected for those batteries ie all under 20, except for the 30Q's which were like 30

I am currently doing a mah test on the triple vtc5a's i was sure were the "good ones" that i mixed up with the others, and if they are higher than the ones already tested i will take the risk to keep those three.

 

[Mooch]

pretty much no one OS ships lion batteries to oz anymore, seriously. Australia post are making it hard to even ship within australia.
If the G320 was damaged, then so would be my alien, my H priv, my snowwolf 365 (which i caught in time), my fuchai duo, my yihi Q, my yihi G, my minikin 2, my ocular touch and my g priv LOL. i highly doubt it, since all checked out as authentic..
those are the affected devices.

I have been researching and apparently the resistance changes... i noticed that on the 2 sets of sony vtc5A where i don't know which were the good or bad, that one set of them reads a higher resistance than the others, by about 20%, so i am *guessing* that they are the bad ones.. still, there is no way to be sure.

What can actually happen here.. explosions?

Do you know that to dispose of them properly, i have to take them to a battery store that does it, there is also nothing close by.. so i am not going to throw them in the bin, will just keep them here for now unless somebody wants them as said.
I called the closest battery world and it's a 40 minute drive! um. No. And i am not allowed to throw in recycle bin. Sigh.

Capacity loss is usually the first sign of aging or a damaged battery. Internal resistance (IR) increases usually follow a bit later. An IR increase can lead to more heating but it's not the equivalent of pulling the pin on a grenade. No matter what, the battery still needs to rise to the venting or thermal runaway threshold temperatures for anything to happen.

 

[Vesh]

That's cool! Thanks. I guess will keep them after all and use them a few times, i am generally a vaper under 50 watts!
Thanks again Mooch.

FWIW, i did resistance tests on the "bad" vtc5a's with the VP4 dragon resistance probes, it is 12um.
That's good, yes?

 

[Vesh]

ok something's up.. the second batch of 3x vtc5a i am testing, has now been in the opus for just under 4 hrs .. they were already at 4.19 volt, so when i started the capacity test, it quickly charged them to 4.21v and then immediately started discharging them..in fact the discharging cycle started within 5 minutes.. it has now been 3 hrs 50 minutes, so 3 hrs and 45 minutes of discharging, at 500ma rate, and the discharge is still only at 3.5 volts. wow. These must be the bad ones and why the others are giving me such good figures. That's basically impossible, it should have already been back on the charge cycle by now for sure. Anyway, will let it run it's course now, and we'll see. Will report back the exact figures, capacities, and then will do the proper resistance test using the xtar probes, when all is done.

I am running the first set of 3xvtc5as in the vp4 and doing it's test cycle, at 1amp this time.. i'll be curious to compare the results to the opus.
As usual, will let y'all know!

The interesting part is that all of these batteries must have been under 2.5 volts for ages.. because most were under 1 volt, many under half a volt.. yet *most* at least seem to be running as normal. Maybe it says something for the quality of sony and samsung chemistry?

 

[Mooch]

That's cool! Thanks. I guess will keep them after all and use them a few times, i am generally a vaper under 50 watts!
Thanks again Mooch.

FWIW, i did resistance tests on the "bad" vtc5a's with the VP4 dragon resistance probes, it is 12um.
That's good, yes?

"12um"?

Charge at whatever will be your "standard" rate for all testing and let sit for one hour to come to room temperature. This is critical.

Take three measurements, removing and reconnecting the probes each time. If the readings are consistent then you're good.

The DC IR for charged healthy VTC5A's at room temp should be about 18mOhms. The AC IR (1kHz) is about 10-12mOhms IIRC.

 

[Vesh]

ok these were not charged, they were at 3.6 volts.. yes 12 milliohms.. the letter the dragon uses to display it is not available on KB.. i presume 12 milliohms is ok then. Don't know what you mean by ac ir.

yes the readings were consistent

next batch of batteries are testing lower.. 2480 mah.. i guess these must be the bad after all but it doesn't make sense cause i was sure they were the good ones that hadn't drained.. i was 98% sure...it's like the bad ones that drained are testing better than the good.. resistance the same, 12.

edit, ok, i presume by ac or dc you mean source of power. the probes on the vp dragon plus plug into a usb port on the back of the device, and the usb port is marked "5v DC".. i don't know if that means anything.
The power adapter for the unit is 12v both AC/DC.

 

[Vesh]

Interesting.. the second set of 3x VTC5A's has settled on 2497, 2525 and 2535 mah.
So, overall the same as the first set. Resistance is also 12. Therefore impossible to ascertain which is good or bad set. The only thing i know for sure, is that i took one set from a mod that i noticed had lowered them, but they were still around 3.5 volts, so had never been under volted, ever. Therefore, i am shocked i am not getting the 2600 mah out of any of them, and this has led to the confusion of which set was good or bad. So what i am going to do is simply keep them all, in specially coloured cases, and just use them till whenever, in a year toss them and go back to my others which i will keep put away at nominal volts in good cases. That'll do. I guess that's it..

Oh i have to ask, what should the resistance be on 30Q's? Mah was great as i said, 3032, no capacity loss there.. so just really need to know what resistance is ok, if it tests ok, i will keep those too. The aspires i am tossing, well, giving to recycling. Too risky, they are the less safe chemistry and have dropped 100 mah so they have definitely been affected.