Recovering Over-Discharged Batteries

[Kemosabe]

man i am having bad luck with batteries lately. well, bad luck is still in question for the MNKEs (backstory here: http://www.e-cigarette-forum.com/forum/apv-discussion/504556-mnke-batteries.html ) but for the sony, its bad luck (or is it me not being careful enough?). i swear i locked my mod. i always lock it. i wonder if there was any other way my batt could have gotten discharged down as low as it did (1.4v). is there any other way?

 

[DrBeaker]

I define "performance" as both; being able to handle amp discharge and battery life.


I know no one likes to waste batteries, but they can be replaced relatively inexpensively when compared to the damage a bad one can make should it go into thermal runaway. It's impossible to know if a battery has internal damage. Having experienced a protected Li-ion battery vent flames in a mechanical mod before, I believe its better to be safe and not sorry.

View attachment 292962

That is exactly what I'm talking about. The metal cans the batterys are made with are designed to vent not explode. My rc motors can draw 20c 30c and even 40c for around 8 to 12 minutes. Thats way more current draw than any mod I know of draws. Its not like your going to get an m80 exploding in your face. I never place my mod down anywhere that I wouldn't put a lit candle.
Charge on a plate tile ect...

 

[Baditude]

That is exactly what I'm talking about. The metal cans the batterys are made with are designed to vent not explode. My rc motors can draw 20c 30c and even 40c for around 8 to 12 minutes. Thats way more current draw than any mod I know of draws. Its not like your going to get an m80 exploding in your face. I never place my mod down anywhere that I wouldn't put a lit candle.
Charge on a plate tile ect...

A battery venting hot gas and flames is bad enough, but if it is venting in an mechanical mod without vent holes then that metal tube mod literally becomes a pipe bomb.



Pic of an AW 18490 IMR battery which vented in a book bag. The accordian-like structure coming out of the battery casing is the internal parts of the battery. Imagine this happening in your mod.

 

[generic mutant]

man i am having bad luck with batteries lately. well, bad luck is still in question for the MNKEs (backstory here: http://www.e-cigarette-forum.com/forum/apv-discussion/504556-mnke-batteries.html ) but for the sony, its bad luck (or is it me not being careful enough?). i swear i locked my mod. i always lock it. i wonder if there was any other way my batt could have gotten discharged down as low as it did (1.4v). is there any other way?

I'm no battery expert, but I believe it's possible for them to develop internal shorts (copper shunts), which would presumably cause them to self discharge.

I wouldn't trust it, personally (I've had a battery that I left for far too long in an unused mod, and it discharged to ~1.5 volts. I chucked it, though it was practically new)

 

[Ryedan]

i have an hcigar nemesis clone scheduled to arrive tomorrow.

Well, FWIW, I have a FT Nemesis clone. With a freshly cleaned Nemesis and one of my Sony 30A 1600mAh batteries at 4.19V, a 0.5 ohm atty I got 3.86V for a second or two, then 3.85 for a few more seconds, then 3.84V. I stopped at about 8 seconds. That battery has had I estimate 60 - 80 charge cycles on it. This voltage drop was the same when it was new. I've also got a couple of other attys set up with different resistances that I could try. I think I've got around 0.6-0.7 and another at around 0.9.

If you change the coil resistance the voltage drop will change significantly and you can't compare that data. However the majority of the voltage drop is from battery sag due to discharge, so even if your mod has slightly different resistance than mine it will likely IMO still be a rough indication of weather your battery has suffered increased internal resistance.

So, do with that what you will and what you're comfortable with. My thought is that if the internal resistance has not changed the battery is good. However that's just my opinion and I'm in no way sure it's the safest way to go.

 

[Ryedan]

I'm no battery expert, but I believe it's possible for them to develop internal shorts (copper shunts), which would presumably cause them to self discharge.

I believe this is true too. Something else that can be used to gauge battery health.

 

[generic mutant]

I believe this is true too. Something else that can be used to gauge battery health.

I meant as a possible initial cause. Problem is I don't know if once they've developed, they'll still self-discharge. Maybe they simply won't retain charge in the first place? So effectively you've reduced the capacity in mAh, though presumably the rest of the battery will still function as normal, so it'll still charge to the same voltage.

I've read once it's happened, they'll heat up more when they're charged / discharged, making them unstable (I think it was somewhere on Battery University).

 

[Ryedan]

I meant as a possible initial cause. Problem is I don't know if once they've developed, they'll still self-discharge. Maybe they simply won't retain charge in the first place? So effectively you've reduced the capacity in mAh, though presumably the rest of the battery will still function as normal, so it'll still charge to the same voltage.

I've read once it's happened, they'll heat up more when they're charged / discharged, making them unstable (I think it was somewhere on Battery University).

Now I understand what you meant. The copper shunts are exactly what happens when you leave them over discharged like they were for days. I believe the Sony was run too long because the lock was left off and it fired by itself.

Kemosabe, correct me if I got that wrong.

 

[zoiDman]

I accidentally allowed my Sony 30A to get discharged to 1.4v. I guess I forgot to lock my chi you, which is uncharacteristic of me.

My xtar vp1 user manual says it can recover most over discharged batts. So I've got it charging now and it has slowly started to recover it. It's up to 3v and counting.

My question is: is it safe to use this batt? Further, is it safe to use this batt up to its original specs? I typically don't go over 10A, sometimes a touch more. Do you think I'll be safe or should I err on the side of caution?

Thanks in advance for any help. Cheers.

Just Curious: How much does a New Battery like the one you Over Drained Cost? 2 Packs/Days worth of Smokes?

I'm not a Battery Expert. So I tend to put things like an Over Drained Battery in the Emergency Back-Up Drawer and buy a New One.

 

[Ryedan]

Just Curious: How much does a New Battery like the one you Over Drained Cost? 2 Packs/Days worth of Smokes?

I'm not a Battery Expert. So I tend to put things like an Over Drained Battery in the Emergency Back-Up Drawer and buy a New One.

Why do you put it in the backup drawer?

 

[zoiDman]

Why do you put it in the backup drawer?

Because it gives me an Excuse to buy a New Replacement.

If I didn't put it away for a Backup, then I would have to Use It. But if I used it, It would mean that it is OK. And if it is OK, then I really Don't Need to Buy a New One. And If I Don't buy a New One, I won't get Vape Mail.

It's kinda a Cascading Logic. But it helps me Sleep Better at Night. At Least until my CC Bill Comes. Then I tell myself that I have to Quit buying things.... Unless something Breaks.

And then it is OK.

 

[Ryedan]

Because it gives me an Excuse to buy a New Replacement.

If I didn't put it away for a Backup, then I would have to Use It. But if I used it, It would mean that it is OK. And if it is OK, then I really Don't Need to Buy a New One. And If I Don't buy a New One, I won't get Vape Mail.

It's kinda a Cascading Logic. But it helps me Sleep Better at Night. At Least until my CC Bill Comes. Then I tell myself that I have to Quit buying things.... Unless something Breaks.

And then it is OK.

LOL, OK, that works for me

 

[DrBeaker]

A battery venting hot gas and flames is bad enough, but if it is venting in an mechanical mod without vent holes then that metal tube mod literally becomes a pipe bomb.

View attachment 293022

Pic of an AW 18490 IMR battery which vented in a book bag. The accordian-like structure coming out of the battery casing is the internal parts of the battery. Imagine this happening in your mod.

Humm very good point... nice picture thank you for the graphic.