Battery Safety Questions

[Continuity]

Oh My Gosh... there is no shortage of mods smoked while charging reports in the various model specific threads. I own an istick 50W, which was absolutely famous for that...

I agree with this - there have been many reports of mainly built-in battery mods going *poof* while charging, that as well as some mods just deciding to autofire to death for no apparent reason. It doesn't seem to happen to quite as many removable battery mods from what I can tell.

...The dose makes the poison here, and I would suggest this is not a consideration with a normal rotation of batteries...

Yeah - I agree with you there. There's no good reason with that charger, and any like it, to watch over it like a hawk and remove the cells as soon as they are charged, not from a POV of losing significant charge or from a safety POV either.

 

[Alien Traveler]

Oh My Gosh... there is no shortage of mods smoked while charging reports in the various model specific threads. I own an iStick 50W, which was absolutely famous for that, at least the earlier output. It's one reason I won't buy an internal battery mod, especially with deeming where this stuff may need to last a long time. This was not theoretical, it was a matter of if the concerns matched the statistical odds, but I'm not going into a long research project to support what I'm saying. And honestly I'm surprised you are not aware of this, being a long time member that has spent a lot of time here.

I remember iStick 50 had a lot of problems, including one case of overheating when charging. But it is (again, as Ego) mod with built-in battery. I may agree that built-in batteries are a bit more dangerous. But I really do not rmember a case of charging went bad for contemporary mod with replaceable battery.

 

[Cohumulone]

I actually appreciate the in depth discussion, regardless of my level of understanding. I do ok filtering the things out that I don't necessarily need. I'm picking up the gist of things.

 

[sonicbomb]

If charger makes batteries hot, then either charger or batteries should be discarded.
If batteries are not warm after charging - why to rest them? Show me any evidence that it can improve safety.

As already stated, with 18650s it's primarily about increasing their longevity.

 

[VNeil]

As already stated, with 18650s it's primarily about increasing their longevity.

If you go back to post #15 you'll see that there is no consensus on this, if that's what you were suggesting...

" Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.

 

[Alien Traveler]

As already stated, with 18650s it's primarily about increasing their longevity.

Even if battery is not warm you recommend to rest it? What are your sources? For how much longevity can be increased? 0.1%? 10%? Does it worth it?

 

[sonicbomb]

If you go back to post #15 you'll see that there is no consensus on this, if that's what you were suggesting...

" Rest batteries after charging
One commonly-reported factor in almost all the incidents we hear of where batteries failed violently while in use is that they were taken directly off the charger and then used immediately, at which point they failed.

Clearly there is no consensus as this thread demonstrates. No one here is an ultimate authority on batteries, certainly not me. I took some advice that makes sense to me from a source I trust and I passed it on. Like any advice it is just advice, you can take it or leave it that's the prerogative of the person receiving the advice..

Even if battery is not warm you recommend to rest it? What are your sources? For how much longevity can be increased? 0.1%? 10%? Does it worth it?

See above. My source is the article written by Rolygate. Does it worth it? That's up to you to decide, as far as I know there's no definitive data on this.

 

[Maiar]

Chiming in a little late. But personally, if the mod requires you to supply your own batteries I'd for sure use a dedicated charger unless it was an emergency and the only option available. However, I don't own any like that as mine all have built in batteries.
That said, you can use basically any USB charging cable if it fits as long as the wall adapter you're using has the same specs as the one that came with the unit. All of mine (iStick 50 x2, iStick 30w, Coolfire IV, Evic VTC) all use a 5V=1A charger and I've never even had a battery get slightly warm while charging. Just gotta make sure about that spec though, I could plug it in to my phone's adapater, but it's a 2A charger and I just assume it would blow up or melt or something.
I've also heard never to plug them into an actual USB port but I do this constantly as well and have never had a problem.

 

[Continuity]

...you can use basically any USB charging cable if it fits as long as the wall adapter you're using has the same specs as the one that came with the unit.

Yes - this is true.

All of mine (iStick 50 x2, iStick 30w, Coolfire IV, Evic VTC) all use a 5V=1A charger and I've never even had a battery get slightly warm while charging. Just gotta make sure about that spec though, I could plug it in to my phone's adapater, but it's a 2A charger and I just assume it would blow up or melt or something.

NO! This is a common misconception. A 2A power supply is *capable* of providing 2 Amps, but it will only put out what the device requires. It's perfectly safe to use - better, in fact, as it has more 'headroom' and you know it isn't being run at its redline.

I've also heard never to plug them into an actual USB port but I do this constantly as well and have never had a problem.

Standard USB 2 ports as still commonly found on a lot of laptops/PCs are capable of putting out 500mA, which isn't really capable of providing the 800mA-1A that a lot of mods use to charge. Not the best idea to use them as you can put stress on the computer's motherboard doing this and maybe blow the USB port.

Some modern computers have USB ports capable of providing more power, from 0.9-1.5A for USB3.

 

[VNeil]

Clearly there is no consensus as this thread demonstrates. No one here is an ultimate authority on batteries, certainly not me. I took some advice that makes sense to me from a source I trust and I passed it on. Like any advice it is just advice, you can take it or leave it that's the prerogative of the person receiving the advice..



See above. My source is the article written by Rolygate. Does it worth it? That's up to you to decide, as far as I know there's no definitive data on this.

Do authoritative sources such as battery university.com recommend resting for safety reasons? Do any charger instruction manuals recommend resting? Food for thought ...

 

[Baditude]

Do authoritative sources such as battery university.com recommend resting for safety reasons?

"Li-ion does not need to be fully charged...nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery. Choosing a lower voltage threshold or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Chargers for consumer products go for maximum capacity and cannot be adjusted; extended service life is perceived less important."

"Venting with flame is connected with elevated temperature. A fully charged battery has a lower thermal runaway temperature and will vent sooner than one that is partially charged. All lithium-based batteries are safer at a lower charge, and this is why authorities will mandate air shipment of Li-ion at 30 percent state-of-charge rather than at full charge. (See BU-704a: Shipping Lithium-based Batteries by Air.).

"Some low-cost consumer chargers may rely solely on the battery’s protection circuit to terminate the charge. Redundancy is paramount for safety, and unknowingly to the buyer, low-cost consumer chargers may be offered that do not have properly functioning charge algorithms. This could be a vehicular charger for a mobile phone or an e-cigarette."

"Besides selecting the best-suited voltage thresholds for a given application, a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. The Li-ion charger turns off the charge current and the battery voltage reverts to a more natural level. This is like relaxing the muscles after a strenuous exercise" (resting the battery - Baditude).

-- Charging Lithium-Ion Batteries, Battery University

One can interpret the above information as they wish. My interpretation says the authors state a battery is most excited physically and chemically when at full charge, and therefore a battery is in its most vulnerable state for a catastrophic failure when in this state. Although the authors do not come out and say so, "resting a battery" after a full charge makes sense from a safety perspective by allowing the battery to internally "settle down" to a more stable state.

Routinely charging a battery to full charge degrades the battery over time more quickly, than if one were to partially charge a battery over its lifetime.

I trust Rolygate as someone whose opinions I respect and trust. Rolygate's suggestion to rest batteries after a charge is just that -- a suggestion". He came to this conclusion after reading multiple incidences of batteries venting or exploding after they were removed from a charger and placed into a mod. Makes sense to me, and doesn't hurt anyone by adopting the practice. Do I practice this each and every time? No, but most of the time I do.

 

[VNeil]

"Li-ion does not need to be fully charged...nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery. Choosing a lower voltage threshold or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Chargers for consumer products go for maximum capacity and cannot be adjusted; extended service life is perceived less important."

"Venting with flame is connected with elevated temperature. A fully charged battery has a lower thermal runaway temperature and will vent sooner than one that is partially charged. All lithium-based batteries are safer at a lower charge, and this is why authorities will mandate air shipment of Li-ion at 30 percent state-of-charge rather than at full charge. (See BU-704a: Shipping Lithium-based Batteries by Air.).

"Some low-cost consumer chargers may rely solely on the battery’s protection circuit to terminate the charge. Redundancy is paramount for safety, and unknowingly to the buyer, low-cost consumer chargers may be offered that do not have properly functioning charge algorithms. This could be a vehicular charger for a mobile phone or an e-cigarette."

"Besides selecting the best-suited voltage thresholds for a given application, a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. The Li-ion charger turns off the charge current and the battery voltage reverts to a more natural level. This is like relaxing the muscles after a strenuous exercise" (resting the battery - Baditude).

-- Charging Lithium-Ion Batteries, Battery University

One can interpret the above information as they wish. My interpretation says a battery is most excited physically/chemically when at full charge, and therefore is at its most vulnerable state.

Routinely charging a battery to full charge degrades the battery over time more quickly, than if one were to partially charge a battery over its lifetime.

I'm sorry but none of that has anything to do with the idea of "resting" after charge. You are (way over) reaching here. That last bolded piece says nothing about time. They could easily mean 2 minutes.

 

[Baditude]

I'm sorry but none of that has anything to do with the idea of "resting" after charge. You are (way over) reaching here. That last bolded piece says nothing about time. They could easily mean 2 minutes.

As I said, one can interpret the information as they wish.

 

[Alien Traveler]

As I said, one can interpret the information as they wish.

And why do not interpret it as it was written?

 

[Baditude]

And why do not interpret it as it was written?

I believe that I did.

 

[VNeil]

As I said, one can interpret the information as they wish.

" a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time"

If you want to reach for an interpretation , the above quote is a good reason NOT to rest the battery, but to get it into service ASAP. It clearly implies that it is a ticking time bomb until you get some voltage shaved off by immediate use.

80-90% of what you quoted was, if anything, recommending pulling the batteries well before full charge. What could that possibly have to do with resting? Why did you even bother to quote all that irrelevant material? A fully charged battery is still fully charged an hour after it's pulled from the charger.

Some context, from your BatteryUniversity link:

Li-ion does not need to be fully charged as is the case with lead acid, nor is it desirable to do so. In fact, it is better not to fully charge because a high voltage stresses the battery. Choosing a lower voltage threshold or eliminating the saturation charge altogether, prolongs battery life but this reduces the runtime. Chargers for consumer products go for maximum capacity and cannot be adjusted; extended service life is perceived less important.

The above discussion is solely focused on maximizing battery life, not a peep about safety. Hey wait, you quoted that to support your position? I'm really confused because it helps make my point.

The below appears to be your smoking gun, the only quoted text that could possibly be divined to refer to battery safety at a full charge....

"Besides selecting the best-suited voltage thresholds for a given application, a regular Li-ion should not remain at the high-voltage ceiling of 4.20V/cell for an extended time. The Li-ion charger turns off the charge current and the battery voltage reverts to a more natural level. This is like relaxing the muscles after a strenuousexercise" (resting the battery - Baditude).

The above is NOT from the page you actually linked, it is from this page: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

The title of which is "How to Prolong Lithium-based Batteries". There is NOTHING on that page relating to safety. It simply discusses, as the title suggests, how to squeeze a few more charge cycles out of your batteries. Yet you quote it, completely out of context, to support your position?

Back to your quoted BU page, this you did not quote to support your position:

Simple Guidelines for Charging Lithium-based Batteries

• 
  
  
  • Turn off the device or disconnect the load on charge to allow the current to drop unhindered during saturation. A parasitic load confuses the charger.
  • Charge at a moderate temperature. Do not charge at freezing temperature. (See BU-410: Charging at High and Low Temperatures)
  • Lithium-ion does not need to be fully charged; a partial charge is better.
  • Not all chargers apply a full topping charge and the battery may not be fully charged when the “ready” signal appears; a 100 percent charge on a fuel gauge may be a lie.
  • Discontinue using charger and/or battery if the battery gets excessively warm.
  • Apply some charge to an empty battery before storing (40–50 percent SoC is ideal). (See BU-702: How to Store Batteries.)

Hmmm... nothing about resting batteries or anything close. Yes, you can interpret overreach for any conclusion you want, but it's not in that article in plain English.

Find me an authoritative article that clearly talks about resting batteries after a charge for safety reasons....

And also, now that you've quoted a bunch of stuff about prolonging battery life, but misinterpreted as dire safety warnings, if our Li batteries are so dangerous at full voltage, and so many of us use them, and so many of us keep them stored properly (in protective cases) at full charge, how many incidents have been reported here of fully charged Lithium batteries, properly stored, spontaneously blowing up? Zero?

 

[Maiar]

Yes - this is true.


NO! This is a common misconception. A 2A power supply is *capable* of providing 2 Amps, but it will only put out what the device requires. It's perfectly safe to use - better, in fact, as it has more 'headroom' and you know it isn't being run at its redline.


Standard USB 2 ports as still commonly found on a lot of laptops/PCs are capable of putting out 500mA, which isn't really capable of providing the 800mA-1A that a lot of mods use to charge. Not the best idea to use them as you can put stress on the computer's motherboard doing this and maybe blow the USB port.

Some modern computers have USB ports capable of providing more power, from 0.9-1.5A for USB3.

Interesting. Thanks for the clarification!