OMG!!!! My battery justn now EXPLODED

[Ryedan]

I ran some numbers comparing AA NiMH cells at 2500 mAh and 16850 Li-ion at 2500 mAh. What I'm seeing is that three NiMH cells either in parallel or series give very similar power, duration and amp draw per cell as the Li-ion. Makes sense because of the voltage difference of the cells.

The same holds for eGo class batteries. It takes three AAA NiHM cells at 1000 mAh to perform as well as one Li-ion at 1000 mAh.

Does this make sense?

 

[MorpheusPA]

"2,000 mAh lithium battery contains right around 7.4 watt-hours."

A 2,000 mAh pack of 4AA batteries contains about 9.6 watt-hours. With the higher voltage, you would want a higher resistance atty to get the same thrill as when vaping at lower voltage with Li-ion.

Since the voltage of 4 series NiMH batteries will be 4.8 V nominal, yes--the voltage of 1 LiMn battery is 3.7. You'd need a higher resistance atty to preserve a delicate liquid's flavor. Like I said above, my sweet spot is actually low at 3.6, so I'd do better with 3 in series for a total of 7.2 watt-hours with the attys I currently use.

Since I don't want to rebuild 72 of the durned things, nor switch to 34 gauge Kanthal, my only other option would be a series resistor in a mech mod. Fortunately, VV or VW mods would handle this for me.

Which is another argument. I'm not sure if 4.8 V would be in-spec for a computer-driven mod. In some cases, it's certain to be in the gap between the high point of a single battery and the low point of a series stack of lithium batteries. At full charge, NiMH will show just under 1.5 V, for 6 V total, and almost assured to be detected as a pair of drained lithium batteries at 3 V each.

10 mL per day seems like a heck of a lot.

My clearos chew liquid and I vape a lot.

 

[MorpheusPA]

"100 mAh per hour vaping"

Undoubtedly that estimate is based on 3.6 or 3.7 volts from Li-ion. When ecig batteries are mentioned, Li-ion are assumed. NiMH are assumed to be non-existent.

You'd still be using about 100 mAh, assuming you held resistance the same and drew from 3 stacked NiMH AAA batteries. Change the voltage, change the mAh per hour average, of course.

 

[Ryedan]

I don't regret this thread. There has been some really great information shared here. The safety awareness being the most important imo. But any info that can be used from this thread is valuable and is beneficial to the forum.
One of the things that has impressed me about this thread is that so far there have been zero posts deleted.

I could not agree more Fisheeboy . It's good to talk things over, learn something and hopefully help someone down the road too.

All good stuff

 

[MorpheusPA]

I ran some numbers comparing AA NiMH cells at 2500 mAh and 16850 Li-ion at 2500 mAh. What I'm seeing is that three NiMH cells either in parallel or series give very similar power, duration and amp draw per cell as the Li-ion. Makes sense because of the voltage difference of the cells.

The same holds for eGo class batteries. It takes three AAA NiHM cells at 1000 mAh to perform as well as one Li-ion at 1000 mAh.

Does this make sense?

Exactly! Nominal voltage on an NiMH is almost exactly 1/3 the nominal voltage of a lithium.

For AAA batteries, I'd be surprised (shocked, even) if you could drain much harder than 2 A without a severe voltage drop, however. Internal impedance is much higher on average in NiMH cells.

Experimenting. I'll report back shortly...

 

[MorpheusPA]

I ran some numbers comparing AA NiMH cells at 2500 mAh and 16850 Li-ion at 2500 mAh. What I'm seeing is that three NiMH cells either in parallel or series give very similar power, duration and amp draw per cell as the Li-ion. Makes sense because of the voltage difference of the cells.

The same holds for eGo class batteries. It takes three AAA NiHM cells at 1000 mAh to perform as well as one Li-ion at 1000 mAh.

Does this make sense?

Very fast experiment done.

Charged Cell, rested: 1.34 V
Same cell being drained at 350 mA: 1.28 V

I'm getting a 0.06 V drop at a piddling 0.35 A draw on a freshly-charged cell. It's a new AC Delco 2500 AA that performs very well, so quality isn't an issue--I'd call any test performed on my no-name 200 cells invalid.

As amperage drain increases, voltage sag will get worse as the chemical reactions in NiMH simply can't keep up.

Fortunately, with NiMH that isn't very dangerous, although internal resistance will cause battery heating if used hard. Lithium is simply better at producing larger amounts of power with minimal heat production and voltage drop.

In an electronic mod, you run the risk of low voltage detection while the batteries still have plenty of power. Additionally, running NiMH under 1 V per cell isn't recommended for best battery life (although I confess I do run some of mine down to 0.7 as that's a transistor's limit of activation through the base--I tend to restrict that to the cheapo cells, though).

The more I think about NiMH, the more I think you need a specific build to successfully use the battery and maintain decent battery life.

 

[Ryedan]

Very fast experiment done.

Charged Cell, rested: 1.34 V
Same cell being drained at 350 mA: 1.28 V

I'm getting a 0.06 V drop at a piddling 0.35 A draw on a freshly-charged cell. It's a new AC Delco 2500 AA that performs very well, so quality isn't an issue--I'd call any test performed on my no-name 200 cells invalid.

As amperage drain increases, voltage sag will get worse as the chemical reactions in NiMH simply can't keep up.

Fortunately, with NiMH that isn't very dangerous, although internal resistance will cause battery heating if used hard. Lithium is simply better at producing larger amounts of power with minimal heat production and voltage drop.

In an electronic mod, you run the risk of low voltage detection while the batteries still have plenty of power. Additionally, running NiMH under 1 V per cell isn't recommended for best battery life (although I confess I do run some of mine down to 0.7 as that's a transistor's limit of activation through the base--I tend to restrict that to the cheapo cells, though).

The more I think about NiMH, the more I think you need a specific build to successfully use the battery and maintain decent battery life.

Excellent stuff Morpheus, thank you sir . I've got to go out for a while but I will get back to this later.

 

[Vapor Vinny]

Hmm.. What to say about that;
... ah ok how about....

I think you mean the drawback for YOU is cosmetic because you don't care for VV, VW etc; YOU are happy with a plain mech.

Er...uh...what to say...yeah man, you can easily use the same batts for a variable voltage, variable wattage, etc...I've built mods with both those specs...hell, even build a flashlight into your mod as I have seen...And really, cosmetically, you can pretty much build it to look any way you want, considering there are cylindrical battery holders for AAAs and AAs...and did I mention it is far safer, even if all we're talking about is how much damage one can do if it explodes?

 

[Vapor Vinny]

Very fast experiment done.

Charged Cell, rested: 1.34 V
Same cell being drained at 350 mA: 1.28 V

I'm getting a 0.06 V drop at a piddling 0.35 A draw on a freshly-charged cell. It's a new AC Delco 2500 AA that performs very well, so quality isn't an issue--I'd call any test performed on my no-name 200 cells invalid.

As amperage drain increases, voltage sag will get worse as the chemical reactions in NiMH simply can't keep up.

Fortunately, with NiMH that isn't very dangerous, although internal resistance will cause battery heating if used hard. Lithium is simply better at producing larger amounts of power with minimal heat production and voltage drop.

In an electronic mod, you run the risk of low voltage detection while the batteries still have plenty of power. Additionally, running NiMH under 1 V per cell isn't recommended for best battery life (although I confess I do run some of mine down to 0.7 as that's a transistor's limit of activation through the base--I tend to restrict that to the cheapo cells, though).

The more I think about NiMH, the more I think you need a specific build to successfully use the battery and maintain decent battery life.

Nice work...but I raised the issue of Nimh only to point out that they're much less dangerous should things go awry...And to educate some newer vapors who have no idea that they can serve as an alternative power source...and that they function quite well.

 

[edyle]

Er...uh...what to say...yeah man, you can easily use the same batts for a variable voltage, variable wattage, etc...I've built mods with both those specs...hell, even build a flashlight into your mod as I have seen...And really, cosmetically, you can pretty much build it to look any way you want, considering there are cylindrical battery holders for AAAs and AAs...and did I mention it is far safer, even if all we're talking about is how much damage one can do if it explodes?

What you said was The drawback with using AAA batteries is you are limited in what you can build in terms of cosmetics.

Quote Originally Posted by Vapor Vinny View Post
I don't think we're taking about the same thing. My mod uses 4 rechargeable AAA batteries you can find at Walmart and requires no special charger. The mod is smaller than most other box mods. The batteries last a good long time. It's certainly cheaper than LIPO batteries in my experience. The drawback with using AAA batteries is you are limited in what you can build in terms of cosmetics.

For me, the drawback with using AAA batteries is I cant fit them in my mods.

How am I going to get VV or VW?

The drawback isn't simply cosmetic - but true, it might be for you; but for most of us vapers out here who WOULD LIKE TO USE THE OPTION of NiMH batteries, we cannot just buy it and use it; if the drawback was just cosmetic, half of us would have been using them already.


Anyway: note to self; this is now off topic, and I don't want to contribute to keeping this headline on the board.


Started a new thread here:
http://www.e-cigarette-forum.com/forum/battery-issues/530278-nimh-batteries-vaping.html

 

[Ryedan]

So NiMH batteries are more tolerant of overcharging than Li-ion and less likely to burn. Compered to IMR or hybrid Li-ion, safety when hard shorted or partially shorted is about the same. The newer Li-ion hybrid technology is so safe, batteries can be hard shorted for a good while (one hour in this video) and the battery not only does not vent, it is still able to be recharged and used.

NiMH batteries are not capable of the high amp discharge that Li-ion are.

ICR Li-ion is a volatile technology and should not be used for vaping even with protection circuits added. I believe eGo batteries are ICR, someone correct me if that's wrong please.

Using the wrong charger on either NiMH or Li-ion batteries is dangerous.

There are no big NiMH cells being made (or they are expensive). Generally three AA or AAA cells are required to provide performance equivalent to one Li-ion cell.

I've probably missed a few points and differences, but these are what stand out for me.

So are NiMH batteries the way to go for vaping? I don't think so. I suspect if the industry switched we would see failure modes with NiMH batteries that we never thought of and that don't happen with Li-ion.

I think that the eGo class batteries would benefit the most from safer technology, but more than 90% of the fires I hear about with these would be avoided if manufacturers simply designed in a feature that would not allow the wrong battery to be attached to a charger.

Any thoughts?

 

[MorpheusPA]

So NiMH batteries are more tolerant of overcharging than Li-ion and less likely to burn. Compered to IMR or hybrid Li-ion, safety when hard shorted or partially shorted is about the same. The newer Li-ion hybrid technology is so safe, batteries can be hard shorted for a good while (one hour in this video) and the battery not only does not vent, it is still able to be recharged and used.

Within limits. NiMH certainly can do nasty stuff, but are unlikely to do so. Li-ion Hybrid pretty much classes the same.

NiMH batteries are not capable of the high amp discharge that Li-ion are.

For the most part.

ICR Li-ion is a volatile technology and should not be used for vaping even with protection circuits added. I believe eGo batteries are ICR, someone correct me if that's wrong please.

ICR with protective circuitry is actually pretty stable. As evidenced by the fact that there are millions in use in many technologies and venting is rare.

That having been said, please give me IMR technology instead as I feel better. When hybrid becomes common, I'll shift to that.

Using the wrong charger on either NiMH or Li-ion batteries is dangerous.

Correct, to a point. NiMH is very tolerant of terrible charging techniques like solar charging at very high temperatures--as long as the charge rate is under 0.1C. NiMH is also very tolerant of voltage variations in charging at low C. Really, my solar chargers are 20-50 ma, and I grab a 3 V cell without bothering to worry about it. The battery doesn't care. Even after it passes the diode (to avoid discharging the battery into the solar cell under dark conditions), applied voltage to a single cell is 2.5 V.

Under moderate to fast charging conditions, NiMH is more tolerant of error than any current lithium--but you still can't push it too far.

There are no big NiMH cells being made (or they are expensive). Generally three AA or AAA cells are required to provide performance equivalent to one Li-ion cell.

Correct, although larger NiMH cells are available (or at least NiCd, which is a valid substitute). I don't wish to carry a lantern battery to vape, however.

I've probably missed a few points and differences, but these are what stand out for me.

NiMH can't be charged as quickly as lithium.

NiMH suffers self-discharge unless you've purchased a ... (Low Self-Discharge) cell and can lose 20% of their capacity in the first 24 hours (although that's the high side). NiCd, a similar but older technology, is similar. Lithium has extremely low self-discharge.

You can't effectively store an NiMH cell for moderate to long periods without recharging. However, self discharge does not harm the cell and NiMH are tolerant of storage in any charge condition except < 1.0 V per cell.

... cells are a bit more expensive and generally feature modestly reduced capacity.

So are NiMH batteries the way to go for vaping? I don't think so. I suspect if the industry switched we would see failure modes with NiMH batteries that we never thought of and that don't happen with Li-ion.

I suspect, but would have to prove by experiment, that the high discharge demands of vaping would kill an NiMH battery fairly quickly--far faster than specification at modest draw.

I think that the eGo class batteries would benefit the most from safer technology, but more than 90% of the fires I hear about with these would be avoided if manufacturers simply designed in a feature that would not allow the wrong battery to be attached to a charger.

Any thoughts?

Pretty much that covers it.

 

[MorpheusPA]

That ... is Low Self Dicharge. Apparently one is not allowed to use the acronym...I can see why.

 

[Burnie]

So NiMH batteries are more tolerant of overcharging than Li-ion and less likely to burn. Compered to IMR or hybrid Li-ion, safety when hard shorted or partially shorted is about the same. The newer Li-ion hybrid technology is so safe, batteries can be hard shorted for a good while (one hour in this video) and the battery not only does not vent, it is still able to be recharged and used.

NiMH batteries are not capable of the high amp discharge that Li-ion are.

ICR Li-ion is a volatile technology and should not be used for vaping even with protection circuits added. I believe eGo batteries are ICR, someone correct me if that's wrong please.

Using the wrong charger on either NiMH or Li-ion batteries is dangerous.

There are no big NiMH cells being made (or they are expensive). Generally three AA or AAA cells are required to provide performance equivalent to one Li-ion cell.

I've probably missed a few points and differences, but these are what stand out for me.

So are NiMH batteries the way to go for vaping? I don't think so. I suspect if the industry switched we would see failure modes with NiMH batteries that we never thought of and that don't happen with Li-ion.

I think that the eGo class batteries would benefit the most from safer technology, but more than 90% of the fires I hear about with these would be avoided if manufacturers simply designed in a feature that would not allow the wrong battery to be attached to a charger.

Any thoughts?

Just wondering about these ? On sale for $2.95 each (+ shipping i'm sure).
4.8V NiMH Battery 600 mAh
Was thinking in a device like the iTaste SVD, which can handle stacked 18350's (which I would not do).
Just a question, sorry it's off topic with the OP.
Thanks for the thread and glad you are OK.

Vape On
Burnie

 

[Ryedan]

Just wondering about these ? On sale for $2.95 each (+ shipping i'm sure).
4.8V NiMH Battery 600 mAh
Was thinking in a device like the iTaste SVD, which can handle stacked 18350's (which I would not do).

Each NiMH cell outputs 1.2V when charged, so this must be a stack of 4 small cells in series. Probably why the mAh is so low.

You are of course correct on this being OT in this thread. I just noticed a little while ago that edyle had started a new thread about NiMH batteries for vaping here

 

[MorpheusPA]

Just wondering about these ? On sale for $2.95 each (+ shipping i'm sure).
4.8V NiMH Battery 600 mAh
Was thinking in a device like the iTaste SVD, which can handle stacked 18350's (which I would not do).
Just a question, sorry it's off topic with the OP.
Thanks for the thread and glad you are OK.

I think they'd work, but for how long is questionable. At 600 mAh, capacity is pretty low and there's no data on the cell's manufacturer or specs. Not to put too fine a point on it, there are a lot more bad NiMH cells out there than good ones.

Plus you need a special charger for the battery; that's one very valid argument for using standard AA or AAA batteries as I already have the chargers kicking around my office.

 

[fogging_katrider]

I'm having some butter pecan ice cream, anybody want some while I'm up?
seems like a good time for some.

oh dang robino, now i have to change out of my soft pants and drive over to krogers... i love butter pecan ice cream

 

[Robino1]

oh dang robino, now i have to change out of my soft pants and drive over to krogers... i love butter pecan ice cream

Ya wanna pick me up some.......I ate all mine.

 

[Racehorse]

I'm a bit creeped out to charge my batteries on my laptop again.

It is really not recommended to charge your batts on laptop using the computer's usb port directly. Almost every computer geek on here will tell you this.

Most everyone uses a wall-powered usb hub with multiple ports. That would be safe. Less than $10 most places. I would get one that can handle a 500 mA load on every port.

I have never charged any device (esp. not an ecig), directly on my laptop or computer usb port. It's like asking for trouble. A usb hub is very inexpensive, and you are not going thru your computer to use it.

 

[rurwin]

I wouldn't worry about using a PC USB port for charging. Any USB device with a USB plug should cope with the full USB spec, and that includes being limited to 100 or 500mA on a computer port. If they can't cope with that then they can always detect that a computer port is connected* and refuse to do anything. Even if they can't work properly, the chances of a catastrophic failure are low. I certainly charge my eGo batteries on a PC.

---
* USB power supplies have their data lines shorted together. USB devices can detect this and know that they are allowed to draw over 500mA.