Safe 18650 battery alternative?

[mwa102464]

Why would anyone continuously use a Batt that they have shorted ? Mine would be hitting the trash if I shorted it. Also dont you think Panasonic has put these through there paces in there testing room ? I do,,,, I've been running both of these Batts for a while now and both seem to be of a very high quality, maybe of the highest quality on the market.

The only good thing possibly, that I saw in the testing when comparing the AW is the AW seemed to push more current, this could be a good thing in a safe situation, but less safe in bad situation.

 

[Rocketman]

When you press the fire button and your atty doesn't heat, what happened?

 

[sailorman]

Why would anyone continuously use a Batt that they have shorted ? Mine would be hitting the trash if I shorted it. Also dont you think Panasonic has put these through there paces in there testing room ? I do,,,, I've been running both of these Batts for a while now and both seem to be of a very high quality, maybe of the highest quality on the market.

The only good thing possibly, that I saw in the testing when comparing the AW is the AW seemed to push more current, this could be a good thing in a safe situation, but less safe in bad situation.

See, that's the thing. The current wasn't being throttled by a PTC on the AW. Imagine how much current the Panny would be pushing if that PTC failed.

It's possible to have an intermittent short. You could be shorting it without even knowing it because nothing much happens except maybe a misfire. I don't know what the spec is for the rated cycles of that PTC. I don't know how much use it can take before it fails. One big short? A million intermittent shorts? Who knows? Callie recharged his after his test, but he didn't short it again and see how it acted. That would have been interesting. Or, if he had subjected it to a bunch of brief shorts, then a big long one. Would it still only have gotten to 135? Who knows.
Got some welders glove, a timer, an infrared thermometer and a pyrex baking dish? Oh, and a video camera?

I'd probably trust them over the **fires, especially if I needed that capacity. But chemistry never fails. I can live with the 185 degrees of the Panasonic near-IMRs.

 

[Creniker]

If you look at the Panasonic Data sheet on their Li-Ions, they have a PTC, (I forgot what the initials stand for) on the top where you would find the PCB of a **Fire protected battery. Somewhere, maybe the Lavatube forum, there is a link to some information explaining what it is. It's a type of current limiting switch. It limits the current dumped from the battery in the event of a short. It doesn't totally cut it off, like a PCB would, but it restricts it.

Now, I'm not 100% sure of this, but I believe that little PTC is not like a PCB in that it can be operated over and over again and perform exactly the same each time. So, if you short the battery out say, 5 or however many times, you won't get the same results each time. Maybe the 1st time the PTC will let the battery get to 135 degrees and the 4th time it will go to 180 and the 5th time it won't work at all. Maybe the first 5 times it will let the battery get to 135 and quit working at all the 6th time. Those results are speculation, but you get my point. That means that the PTC could conceivably have been switched on, even for a moment, without your knowledge. At any given moment, you wouldn't know how many activations it's been subject to. So, how would you know how safe it is to rely on? Maybe it fails entirely after 25 activations. Maybe it's already been subject to 24 brief shorts without you knowing. Remember, all this is hypothetical and based on the assumption that the PTC has a limited number of duty-cycles.

In contrast, safe chemistry batteries work once, every time. Their characteristics are universal. Assuming the same amount of a chemical, it's going to act the same way every single time. You won't have a brief short that doesn't do anything, but makes the consequences worse during the next short.

The point I was making was that batteries with a safe chemistry, like an IMR, act according to their chemistry and they will be consistent from one battery to the next, so it makes no sense to test 10 of them the same way, unless you're engaged in quality control testing.

Personally, I'd rather rely on a batterys chemistry than a device, unless the difference is super-critical. With PV's, I don't think the difference between a 135 degree short and a 185 degree short is critical. I wouldn't trust a PTC after the first short in anything I put near my face. I might re-use it in a flashlight though.

Thats basically what I thought you were getting at, that the IMRs are inherently safer. Thank you for the great explanation.

And mwa I agree about using a battery that has been shorted. Though sailor did bring up a good point that you might not know it shorted, as it could've been a very small short that lasted for perhaps a tenth of a sec.

 

[mwa102464]

All I can say is I've been using 2 of the 2250 IMR Callies ( Panasonic's ) and 2 of the Callies 3100's in 4 Mods daily for some time now, just testing them under vaping conditions and they are performing super, really super, the IMR seems to be holding higher voltages for longer times then my AW IMR's, the 3100 is also giving me long run times. I like them both very much and would recommend these Batts to be used in Mods. It can be a toss up at times which is safer having a protected Batt vs an IMR , protected still gives you protection, and Sailorman brings up a very good point about the protection used in these, I will have to do a bit more investigation on this protection, I myself would like to know more about it and if it trips what state the Batt is then in for use again,,,, I yield to the side of IMR right now over the protected because of the chemistry make up of the IMR itself.

 

[Strontium]

I agree with you. 185-240 degrees is way too hot. That is the reason why I purchased the Panasonic NCR18650A. Let me summarize the results of the videos I posted previously.


Panasonic CGR18650CH 2250mah (unprotected): http://www.e-cigarette-forum.com/fo...-18650-battery-alternative-3.html#post5527483
(video start at the beginning to about 1:49)

-After shorting for approximately 3 minutes, the temperature reached approx 185 degrees
-Battery was no longer usable.


AW IMR 1600mah (unprotected): http://www.e-cigarette-forum.com/fo...-18650-battery-alternative-3.html#post5527483
(video start at 1:50 to end )

-After shorting for approximately 1 minute 40 seconds, the temperature reached approx 235 degrees
-Battery was no longer usable.


Panasonic NCR18650A 3100mah (unprotected): http://www.e-cigarette-forum.com/fo...-18650-battery-alternative-2.html#post5527470

-After shorting for approximately 1 hour, the temperature reached approx 130-135 degrees
-Battery was able to be charged and remained usable.

Notes:
-The Unprotected Panasonic CGR18650CH and the AW IMR are rated at 10A
-The Unprotected Panasonic NCR18650A is rated at 8.5A

I am no electrical/electronic engineer but if all these batteries are considered to be “reasonably safe”, what is the need for 10A of current? An unprotected Panasonic NCR18650A is rated at 8.5A. Most PVs are limited to 2.5-3.5A right? Perhaps I should open another thread for this question.

If I had to draw a conclusion from the evidence of the videos linked above, I would have to say that the unprotected Panasonic NCR18650A is safer. It performed better when shorted, had a lower temperature when shorted and was still usable after the test. To reiterate, this is if I HAD to draw a conclusion from the videos.

You are maybe the closest to the final answer to this pretty confusing question: best balance between safety,energy,capacity.

Read this PDF doc (ncr18650a Panasonic), and pay attention on paragraph about HRL .

https://industrial.panasonic.com/www-data/pdf2/ACI4000/ACI4000CE25.pdf

And for all folks who maybe wondering how is it possible for ncr18650a to be in usable condition after short circuit occurs, the answer is PTC which is part of that Panasonic cell.

It heats up - stops the current. It cools down - current can flow again.

That is how PTC works.

 

[sailorman]

You are maybe the closest to the final answer to this pretty confusing question: best balance between safety,energy,capacity.

Read this PDF doc (ncr18650a Panasonic), and pay attention on paragraph about HRL .

https://industrial.panasonic.com/www-data/pdf2/ACI4000/ACI4000CE25.pdf

And for all folks who maybe wondering how is it possible for ncr18650a to be in usable condition after short circuit occurs, the answer is PTC which is part of that Panasonic cell.

It heats up - stops the current. It cools down - current can flow again.

That is how PTC works.

That's all true, but it still doesn't answer the question of whether or not the PTC has an unlimited number of duty-cycles. What is the substrate? Does it degrade after repeated heating and cooling? It's something "oxide" IIRC from the other data sheet. I'd ask the same thing about the "HRL". What is a "heat resistant layer"? Sounds good in marketing literature. Does it simply keep the casing of the battery cooler? What effect, if any, does it have on the internal temperature? Does that even matter? I don't know.

By Panasonics own chart on that same page, batteries with their "PSS" technology (cgr18650ch) are safer than the Li-Ion ncr18650a, albeit with lower capacity. So, it's a tradeoff. In the case of my only 18650 PV, a Lavatube, the 2250mah cgr has more than adequate capacity for me, especially given the price difference. I definitely would like to try these in my 4X18650 battery pack for my bike light. In that application, pretty safe is safe enough and I could definitely use the extra capacity.

 

[Strontium]

That's all true, but it still doesn't answer the question of whether or not the PTC has an unlimited number of duty-cycles. What is the substrate? Does it degrade after repeated heating and cooling? It's something "oxide" IIRC from the other data sheet. I'd ask the same thing about the "HRL". What is a "heat resistant layer"? Sounds good in marketing literature. Does it simply keep the casing of the battery cooler? What effect, if any, does it have on the internal temperature? Does that even matter? I don't know.

By Panasonics own chart on that same page, batteries with their "PSS" technology (cgr18650ch) are safer than the Li-Ion ncr18650a, albeit with lower capacity. So, it's a tradeoff. In the case of my only 18650 PV, a Lavatube, the 2250mah cgr has more than adequate capacity for me, especially given the price difference. I definitely would like to try these in my 4X18650 battery pack for my bike light. In that application, pretty safe is safe enough and I could definitely use the extra capacity.

Sailor,

One question before I provide some info on this topic.

If a circuit breaker breaks one el. circuit in your household multiple times, are you going to check el. circuit in your house, or you will continue with resetting that particular breaker?

I am using name circuit beaker, not a fuse with a good reason. Everybody should know what is difference between these two.

 

[Strontium]

Why would anyone continuously use a Batt that they have shorted ? Mine would be hitting the trash if I shorted it. Also dont you think Panasonic has put these through there paces in there testing room ? I do,,,, I've been running both of these Batts for a while now and both seem to be of a very high quality, maybe of the highest quality on the market.

The only good thing possibly, that I saw in the testing when comparing the AW is the AW seemed to push more current, this could be a good thing in a safe situation, but less safe in bad situation.

Thank you.

That is exactly what I am trying to say.

Pure IMR > safe chemistry - yes. Inside the cell.

But, what about when you get external short circuit from PV. IMR will push 40A - 50A out. 40A is not a joke, but serious safety issue.

How safe chemistry will be safe if everything outside that pure IMR cell is burning, and melting.

 

[That_Dude]

I know this is a 3 month old thread, but reading this has officially scared the crap out of me. I admit I can be a little paranoid but this has me really freaked out. I read the whole thread but I swear most of it was beyond my comprehension. I got 2 IMR 18650 3.7v 1600maH batteries with my vtube. Are these considered safe? I worry just as much about the craptastic charger that was included with the set. Someone please put my mind at ease and tell me what to buy lol. New charger, new batteries, whatever. I cant imagine quitting smoking getting healthy and blowing my face off. Over dramatic? Absolutely, but im non the less dead serious. Thanks.

 

[Rocketman]

$10 Digital Voltmeter