18650 Battery Safety

KeroZen

Chronic vapaholic
So the 8x LiFe cells arrived from China (and it was indeed the slow boat) They are A123 APR18650M1A and appear on the exterior at least to be genuine. Here's the datasheet:

https://www.batteryspace.com/prod-specs/6612.pdf

...but Fasstech also says that they are salvaged from unsold inventory of power tool packs etc and that some might be desoldered. I don't see any weld marks on mine though, they look like new. They might surely be old-stock, I don't think they are still in production.

I just charged one, it took around 850mAh in until the charger cut. Then the resting voltage slowly dropped down from 3.6V to 3.34V where it seems to have stabilized now.

Anyway, from the graphs above it looks like my 0.5ohm load (high power Nomad heater module) will make the cell sag somewhere around 3V for a good deal of the run. I like how flat the discharge curves look. Even more interesting is the 20A graph where the voltage dips then goes up again as charge drops.

The 30A CDR is very nice. Ability to fast charge up to 4A is also a very good selling point. And yes the incredible cycle life and slow degradation. And did I mention how dirt cheap they were?!

They shouldn't be discharged past 2V, as I read they get damaged like other Li-Ions, so a low-voltage protection of some kind is still recommended.

I'll test it in the Nomad soon but I'm afraid it will feel a bit anemic by producing only around 20W. That being said 30W is ample enough for on demand convection already so... we'll see!
 

looney2nz

Research Geek, Mad Scientist
So the 8x LiFe cells arrived from China (and it was indeed the slow boat) They are A123 APR18650M1A and appear on the exterior at least to be genuine. Here's the datasheet:

https://www.batteryspace.com/prod-specs/6612.pdf

...but Fasstech also says that they are salvaged from unsold inventory of power tool packs etc and that some might be desoldered. I don't see any weld marks on mine though, they look like new. They might surely be old-stock, I don't think they are still in production.

I just charged one, it took around 850mAh in until the charger cut. Then the resting voltage slowly dropped down from 3.6V to 3.34V where it seems to have stabilized now.

Anyway, from the graphs above it looks like my 0.5ohm load (high power Nomad heater module) will make the cell sag somewhere around 3V for a good deal of the run. I like how flat the discharge curves look. Even more interesting is the 20A graph where the voltage dips then goes up again as charge drops.

The 30A CDR is very nice. Ability to fast charge up to 4A is also a very good selling point. And yes the incredible cycle life and slow degradation. And did I mention how dirt cheap they were?!

They shouldn't be discharged past 2V, as I read they get damaged like other Li-Ions, so a low-voltage protection of some kind is still recommended.

I'll test it in the Nomad soon but I'm afraid it will feel a bit anemic by producing only around 20W. That being said 30W is ample enough for on demand convection already so... we'll see!
I wonder how two of 'em would do in an Invoke 220?
 
looney2nz,
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KeroZen

Chronic vapaholic
Capacity is super low though. I tried 4A charging as in the datasheet but it took longer than the 15 minutes listed and the charging curve was quite unusual... Will need to do more tests.
 
KeroZen,

showman

Well-Known Member
i thought i had a datasheet for the 18650, but i guess i didn't save it, but i would swear that the characteristics were identical to the 26650, except less capacity of course. i.e. 70A discharge rate and voltage has an extremely sharp knee at the end of the discharge - plus the 1000x recharges before losing 20% capacity.

i got some 18650 from China several years ago, but i decided they weren't genuine - can't remember why i decided that. i think i posted that in a thread somewhere.
Here are the specs of the 18650 LifePo4:
https://www.batteryspace.com/prod-specs/6612.pdf
 

djurodjakovic

Well-Known Member
first time hear of these. thanks.
can I use these in focus vape? anything to be careful about (mAh,...)?

edit
I checked on the web. it seems the dimension is d=21mm and l=70mm and the 18650 is d=18mm, l=65mm so I don't think this will fit :-(.
 
Last edited:
djurodjakovic,

looney2nz

Research Geek, Mad Scientist
Capacity is super low though. I tried 4A charging as in the datasheet but it took longer than the 15 minutes listed and the charging curve was quite unusual... Will need to do more tests.
I wonder who's making cells like these now and if they would tailor some in a 21700 package for higher voltages and mah? 2 in an invoke with a QQ on it, that would be a ballsy test. So much cooler for a safer package and an interesting trade of factors in their old packaging.
 
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KeroZen

Chronic vapaholic
Well the fate of A123 systems is a bit unclear... They were basically dead but now are Chinese owned and expected to make a come back at some point.

https://en.wikipedia.org/wiki/A123_Systems

In the mean-time it appears all cells still available are old-stock (but since LiFePO4 has an excellent shelf life they should still be pretty good)

Tested mine in the Nomad and it was better than expected... but only for a very short while! I get like 1.5 sessions per charge max, but that session is quite good and the heater still performs well (I feared it would be anemic but nope) Keep in mind my sessions are longer than the average user and harder on the cell (I get somewhere like 30 hits with the same quantity than other users, where they get like 6-10 hits)

If I had a very compact and portable 4A charger maybe that could work... but otherwise capacity is really on the low side and it shows. Would need to carry a lot of cells with me for it to be a viable option.

That being said, I have plenty of other applications in mind, as their voltage is perfect for 3.3V electronics without needing any kind of voltage regulation, just a low-voltage protection would be required.
 

bossman

Gentleman Of Leisure
I posted this question in a Splinter or Tubo thread: what 18650 should I buy to complement my six 30Qs?

I use them for a Lil Bud, Tubo X, Splinter, and Splinter Z via three TC mods and a bronze wismec dna250 that doesn't fit the three 30Q cells properly.

Sony VTC5A or what? The only use I anticipate is on demand convection devices, mostly regulated plus the LB.
 
bossman,

macbill

Gregarious Misanthrope
Staff member
Fort Worth man dies after vape pen explodes in his face, report says

A 24-year-old Fort Worth man died last month after his vape pen exploded in his face, according to the Tarrant County medical examiner’s office.

William Brown was at a vaporizer store in Keller when it happened. His grandmother, Alice Brown, said he had just purchased the device and was using it for the first time in her car.
 
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invertedisdead

Defenders Of Glass
Fort Worth man dies after vape pen explodes in his face, report says

A 24-year-old Fort Worth man died last month after his vape pen exploded in his face, according to the Tarrant County medical examiner’s office.

William Brown was at a vaporizer store in Keller when it happened. His grandmother, Alice Brown, said he had just purchased the device and was using it for the first time in her car.
Wonder if this was another unregulated mechanical mod related incident like most of these stories are?
 
invertedisdead,
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macbill

Gregarious Misanthrope
Staff member
Wonder if this was another unregulated mechanical mod related incident like most of these stories are?
The article said he had just purchased it, and was using it for the first time. , A commenter in another forum posits it may have been a cheap knock-off without any safeguards
 

cybrguy

Wear a Mask, Damnit
Why would the article not mention the make and model of the exploding ecig? Shouldn't there be a reasonable effort to inform? Come on...

From another article: "Smoke and Vape DZ told CBS 11 Brown didn’t buy anything, but wanted help using a Mechanical Mod style vape pen. The manager said they don’t sell the brand because it’s been known to have issues."
 

invertedisdead

Defenders Of Glass
I assume by "Mechanical Mod" they mean something unregulated?
That's pretty much how all of these cases seem to happen, incorrect understanding of Ohms Law + 18650 battery + unregulated mod = hand grenade

I'd be curious in hearing of these cases happening with regulated mods? I feel like these manufacturers honestly don't want their mods exploding cause that's just not good for business PR. These injuries seem to largely be a mech mod thing.
 

looney2nz

Research Geek, Mad Scientist
That's pretty much how all of these cases seem to happen, incorrect understanding of Ohms Law + 18650 battery + unregulated mod = hand grenade

I'd be curious in hearing of these cases happening with regulated mods? I feel like these manufacturers honestly don't want their mods exploding cause that's just not good for business PR. These injuries seem to largely be a mech mod thing.
and are these more common to nicotine focused vapes?
 
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