Battery testing - choices for series circuits

[AriM]

I believe its unecessary. Yes, resistance fluctuates as the heating element heats up, but simulating atty loads does us little good anyway as most (14500 or larger) batteries have the amperage necessary to power our atomizers with minimal heat rise, so little useful data is gained other then to say, yes, it went X minutes at this load or achieved X mAh or X cycles.

Maxing out the batteries and testing their max C ratings will give us much more information about their capabilities, failure thresholds and max temperatures achieved.

Weird, because the question I get asked more than anything else is about run times. So it's relevant. We can agree to disagree though. The other tests are certainly important and valid, but do not simulate real world vaping...

The other issue is that while vaping....the atty is asking for different parameters as the battery flattens, so as the voltage goes down, the load remains the same....so therefore the current asked of the cell also goes down...I think it's important in testing to show that

 

[AriM]

AW LiFePO4 3.0/3.2V 16340 Results

AW's Listed C rating: 5C

I subjected them to max load ratings, way beyond what our ecigs draw. I tried to get 4 of them to fail by subjecting them to a 10amp continuous load (20+watts) and draining them down to zero volts. They reached 180F, but none of them failed or leaked.

If you have trouble viewing the graphs, they can be found here: Super T Manufacturing, Innovative manufacturer of electronic cigarette products.

5 Amp Continuous Load, Stacked Cells:

5 Amp Continuous load, Single Cell:

10 Amp Continuous load Single Cell (over twice their rated amps):

5 Amp Duty Cycle. 5 secs on, 20 secs off, Single Cell:

I see you are using the CBA 3?

 

[rolygate]

Please let's not argue about points that may not be important. We know we'll have to suggest some batteries that are safe at 4C or 5C (or whatever it is), but although it may be nice to have a safety factor of 2 and be able to go to 10C, it seems unnecessary in the circumstances. We just need to know what works well at 5C.

I am asking you to not get diverted into debates about the occasional thing someone may say without thinking. Let's keep our minds on the prize: batteries good for series use at 4C - 5C. We need to make progress, for the good of the community. It's not about us, it's about them.

Thanks.

 

[AriM]

Please let's not argue about points that may not be important. We know we'll have to suggest some batteries that are safe at 4C or 5C (or whatever it is), but although it may be nice to have a safety factor of 2 and be able to go to 10C, it seems unnecessary in the circumstances. We just need to know what works well at 5C.

I am asking you to not get diverted into debates about the occasional thing someone may say without thinking. Let's keep our minds on the prize: batteries good for series use at 4C - 5C. We need to make progress, for the good of the community. It's not about us, it's about them.

Thanks.

Roly,

I think it's pretty important. If someone is going to come in here and make claims that XYZ battery can take 10c, they should be willing to take some accountability for those claims. After all, that is what we are chasing right?

BTW I am still waiting on the outline for testing. I have a source for the Tenergy batteries. As soon as I know we are all on the same page, I will order them.

I fear it may be impossible to get to a result though. If Super-T is willing to make statements that a LiFEpo4 stack is "safe" at 10c. There is no way I can back that claim up. Even if the batteries did not fail....that is not safe.

So how do we reach a result? If one tester says one thing, and I say another? Which is valid? I suppose this is where ECF has to make a decision about which data to use. Again it really comes down to the testing methodology. This is why I suggested the "real world" vaping test. Using constant resistance, and the batteries housed in a tube mod during testing.


P.S. Another issue of concern are the stamped mah ratings on batteries. How do we verify what 5c really is, if the stamped rating is inaccurate. I suppose the best way is to peak the cell and track the mah that the cell took. In many cases we will have to ignore the mah rating on the tenergy LiFEpo4's...as it's not accurate

 

[forcedfuel50]

I was under the impression that the purpose of the thread here was to get legally binding endorsements about specific batteries. I can see we aren't ever going to get there. Pity....

In all due respect, yes, you were under the wrong impression, but if that was your personal goal, maybe it's time to move on?

As before, there is no liability for testers, as in the end the advice will come from ECF. We need safe choices above all else.

This thread and subsequent testing isn't about "gotcha's" and legal liability. You are not an attorney, so quit acting like you're the liability police. Keep it up, and no one will want to cooperate.

This thread is about coming together as a community in hopes of improving the safety for all involved. It is about testing batteries to see if they are "safe" and suitable for use in stacked situations so that ECF may make recommendations. I will reiterate as evidently you missed my previous statement:

"We don't manufacture the batteries, we just test them so all we can say is our testing of a particular batteries output will meet the demands of X device. If you want someone to make legally binding statments for a particular C rating, you'll have to bring the manufacturers in like Panasonic, Tenergy etc...."

I fear it may be impossible to get to a result though. If Super-T is willing to make statements that a LiFEpo4 stack is "safe" at 10c. There is no way I can back that claim up. Even if the batteries did not fail....that is not safe.

Also, just to clarify, i never said LiFePO4's are safe at 10C. I said that i could not induce a failure at 10C, a very big distinction.

 

[forcedfuel50]

Also AriM, though vape time testing via resistance is interesting, it won't help us to determine whether a particular battery is safe so it's probably better suited for a new thread. It will only tell us that brand X lasts this long and brand Y this long and even then it will still be subjective.

Everyone varies the length of their draws and rest time in between draws, thus you would have to average the draw and rest times. As we know, if you plug averages into the equation, then your results could vary widely depending on the user, negating the specificity you were seeking in the first place.

 

[AriM]

In all due respect, yes, you were under the wrong impression, but if that was your personal goal, maybe it's time to move on?



This thread and subsequent testing isn't about "gotcha's" and legal liability. You are not an attorney, so quit acting like you're the liability police. Keep it up, and no one will want to cooperate.

This thread is about coming together as a community in hopes of improving the safety for all involved. It is about testing batteries to see if they are "safe" and suitable for use in stacked situations so that ECF may make recommendations. I will reiterate as evidently you missed my previous statement:

"We don't manufacture the batteries, we just test them so all we can say is our testing of a particular batteries output will meet the demands of X device. If you want someone to make legally binding statments for a particular C rating, you'll have to bring the manufacturers in like Panasonic, Tenergy etc...."



Also, just to clarify, i never said LiFePO4's are safe at 10C. I said that i could not induce a failure at 10C, a very big distinction.

Sorry, I didn't realize that you were the one organizing the test and running the thread. Also, if no one wants to take legal acountability, then they shouldn't be involved, because if someone gets hurt....who do you think it's going to come back on? Probably ECF and the testers involved. I think Roly pretty clearly outlined his concerns in an earlier post (post #27 in this thread). If there is legal accountability, it's far more likely that the vaping community will benefit ten fold. That way when something bad finally does happen (not if, but when) we can all wash our hands as a community and say that we provided "safety recommendations". Anything else is just conjecture and open to legal debate.

I don't know why you feel hostile about the matter

 

[AriM]

Also AriM, though vape time testing via resistance is interesting, it won't help us to determine whether a particular battery is safe so it's probably better suited for a new thread. It will only tell us that brand X lasts this long and brand Y this long and even then it will still be subjective.

Everyone varies the length of their draws and rest time in between draws, thus you would have to average the draw and rest times. As we know, if you plug averages into the equation, then your results could vary widely depending on the user, negating the specificity you were seeking in the first place.

That is why I would suggest both a duty cycle test (with constant load) and the constant resistance test. I mean if the data is going to be generated, and we are going to take the time to employ proper testing methodology, why not grab all the data we can? Also isn't safety a multifaceted statement? Hard to know why you are so opposed to my concerns. Like you said maybe this isn't the right place for my personal goals, and maybe I should move on and just post the data where it can be better appreciated.

 

[forcedfuel50]

Look AriM, you and i can piss back and forth all day and take this way off topic. If you want to test estimated vape times, by all means, go ahead and do so. You asked in an earlier post if we thought it was necessary and i replied.

The testing i did was to determine if the AW LiFePO4's could sustain their manufacturers claimed C ratings and i even took it one step further to see if i could induce failure by driving them past their C ratings. Given my testing vs the amperage draw required of our PV's, the AW LiFePO4 can sustain the necessary current needed.

Does this make it "safe"? Personally, i take the "reduced risk/harm" approach and do not recommend stacking batteries as I believe there to be safer alternatives to achieve higher voltage, even if the batteries themselves can handle the amperage demands. But if it is legal liability you seek, feel free to do your own testing and have an attorney write you out a legal liability statement holding you liable and sign you name and contact information to it for us.

Back on topic,

I will also be testing the Tenergy LiFePO4 with the same parameters and will post up my results. Based on previous feedback on the Tenergies, i expect similar results but only testing will tell the tale.

 

[rolygate]

Our goals
What we hope to achieve is an addition to the Rechargeable Batteries info page. It would be a new, small section that might go something like this:

------------------------
Batteries for series use
When using batteries placed in series ('stacking' them) for double the voltage for 6 volt vaping or higher, there is evidence that more care should be taken. Currently we suggest that the following batteries are a better choice than some others available:

for 6 volts:
AW 3v Li-FePo4 model xxxx
Tenergy 3v Li-FePo4 model xxxx

for >7 volts:
xxx xxxxxxxx xxxxxxx
xxx xxxxxxxx xxxxxxx


We believe that safer-chemistry batteries should be used for series duty. Unprotected Li-ion batteries should not be used, especially in series.

It is important that batteries should be sourced from reliable vendors, because there are a great many counterfeit batteries in circulation.
-------------------------


Source / attribution
We did not give the names of all the people who contributed to the info on the current page, and quoted no refs except some vague sources of info. It's an ECF-suggested resource as against coming from a person or persons specific. The advice comes from us. But if someone asks to be named we will gladly do so.


What is the reason
To stop someone buying two unprotected Li-ion batteries and stacking them. To stop members telling other members (especially beginners) to do that.

Once you have told someone what not to do, you have an obligation to tell them what they can do - otherwise it's just a cop-out. It would be responsible for ECF to ask those with the specific ability to test two batteries in series to advise us.


We don't have any other aims or goals here - just as above.

If the text/wording is wrong then let's adjust it.

 

[AriM]

Look AriM, you and i can piss back and forth all day and take this way off topic. If you want to test estimated vape times, by all means, go ahead and do so. You asked in an earlier post if we thought it was necessary and i replied.

The testing i did was to determine if the AW LiFePO4's could sustain their manufacturers claimed C ratings and i even took it one step further to see if i could induce failure by driving them past their C ratings. Given my testing vs the amperage draw required of our PV's, the AW LiFePO4 can sustain the necessary current needed.

Does this make it "safe"? Personally, i take the "reduced risk/harm" approach and do not recommend stacking batteries as I believe there to be safer alternatives to achieve higher voltage. But if it is legal liability you seek, feel free to do your own testing and have an attorney write you out a legal liability statement holding you liable and sign you name and contact information to it for us.

Back on topic,

I will also be testing the Tenergy LiFePO4 with the same parameters and will post up my results. Based on previous feedback on the Tenergies, i expect similar results but only testing will tell the tale.

You seem to be missing the point. This a public forum, where all of our statements can be seen. I am not advocating going out and getting legal waivers, that do or do not limit liability. What I am saying, is that if there is a problem...and there will be eventually, any sue happy lawyer can go out to ECF and find our names and hold us to our claims. Is there any merit to such action? No, but I don't want to have to defend claims later down the line, that may or may not be safe. Ya dig?

It's not a matter of pissing contest. It's a valid concern of mine about this testing. If you think it's overboard, that's also fine. You are entitled to an opinion (as am I). I would think that ECF and anyone willing to make claims about safety, should be very concerned about the legal implications, that's all.

I think that to do any less would not follow due process, and it would be negligent. If you want to run the tests, go for it. If, you want to make claims on a public forum about limitations, that's also great. I am simply saying that I won't do the same. I won't go out and say that an AW IMR 18490 is safe to run at 10 amps, because as soon as I do, someone out there is going to go out and start running them at 20 amps. So why not rate the batteries conservatively, which will still easily get us to where we can have nice thick vapor.

 

[AriM]

Our goals
What we hope to achieve is an addition to the Rechargeable Batteries info page. It would be a new, small section that might go something like this:

------------------------
Batteries for series use
When using batteries placed in series ('stacking' them) for double the voltage for 6 volt vaping or higher, there is evidence that more care should be taken. Currently we suggest that the following batteries are a better choice than some others available:

for 6 volts:
AW 3v Li-FePo4 model xxxx
Tenergy 3v Li-FePo4 model xxxx

for >7 volts:
xxx xxxxxxxx xxxxxxx
xxx xxxxxxxx xxxxxxx


We believe that safer-chemistry batteries should be used for series duty. Unprotected Li-ion batteries should not be used, especially in series.

It is important that batteries should be sourced from reliable vendors, because there are a great many counterfeit batteries in circulation.
-------------------------


Source / attribution
We did not give the names of all the people who contributed to the info on the current page, and quoted no refs except some vague sources of info. It's an ECF-suggested resource as against coming from a person or persons specific. The advice comes from us. But if someone asks to be named we will gladly do so.


What is the reason
To stop someone buying two unprotected Li-ion batteries and stacking them. To stop members telling other members (especially beginners) to do that.

Once you have told someone what not to do, you have an obligation to tell them what they can do - otherwise it's just a cop-out. It would be responsible for ECF to ask those with the specific ability to test two batteries in series to advise us.


We don't have any other aims or goals here - just as above.

If the text/wording is wrong then let's adjust it.

Sounds good to me Roly. My only concern is that, like it or not, we are all named as long as threads like this one, and data is out there on the forum. It wouldn't be hard for someone to put names to the recommendations (if they found it necessary to find such information). For example...

"My client found such recommendations and data on ECF, by members named xyz, abc."

Like forcedfuel said, people shouldn't be scared off by legal claims or implications....but it's a real scenario. People are sue happy these days, and I would hate for the scenario you described in post #27. So we should all be very cautious and informed about the legal implications. After all, we have all seen (and know) what is coming down the pipe for the vaping community. I have no doubt that the government agencies will step in and regulate this industry at some point soon. Let's not give them any legal reasons to cite battery explosions or dangers. I really think we should take that approach, because that is the way it works in the real world (sadly so).



P.S. Roly, how about we also include some words about using some form of sleeve, when stacking cr123 sizes in an 18650 size tube. Even if we simply say wrap your "stack" in tape, to avoid shorting of unprotected batteries....

 

[rolygate]

Sleeving: sounds good.

If anyone wants this discussion moved to a private forum then that is probably a good idea. Or maybe say if you don't want that done, as it seems a good idea.

 

[forcedfuel50]

You seem to be missing the point.

Clearly I am, as you have contradictied yourself as earlier you even said it was, quote, a "Pity" that we wouldn't publicly acknowledge and accept legal liability:

I was under the impression that the purpose of the thread here was to get legally binding endorsements about specific batteries. I can see we aren't ever going to get there. Pity....

And you said:

So here is the problem....earlier you said that the cells are good for "10c", but you won't back that up with a legally binding statement. You just differ to the manufacturer. There is the problem....you can't say it's good for 10c and then not be willing to take some accountability for that claim....

And then when i asked you to take legal liability for your testing, you do an about face:

If, you want to make claims on a public forum about limitations, that's also great. I am simply saying that I won't do the same. I won't go out and say that an AW IMR 18490 is safe to run at 10 amps, because as soon as I do, someone out there is going to go out and start running them at 20 amps.

And:

I am not advocating going out and getting legal waivers, that do or do not limit liability. What I am saying, is that if there is a problem...and there will be eventually, any sue happy lawyer can go out to ECF and find our names and hold us to our claims. Is there any merit to such action? No, but I don't want to have to defend claims later down the line, that may or may not be safe. Ya dig?

Yeah, I "Dig". Earlier you wanted us to make legally liable endorsements, but you won't do the same with your testing as you "don't want to have to defend claims later down the line" and i see you even went in and edited out your earlier quote I memorialized at top. This shows a bias and agenda to me.

 

[AriM]

Sleeving: sounds good.

If anyone wants this discussion moved to a private forum then that is probably a good idea. Or maybe say if you don't want that done, as it seems a good idea.

I am personally ok with it being public. If we keep the ratings conservative, I see no reason to be worried. Maybe the final testing and "certified" results should be sent privately though. This way no member is personally liable for any recommendations, other than their own.

Also here is a sample test of the AW stack. Also a picture of the test rig I have set for this specific test. The batteries are housed in a metal tube, with a cardboard "sleeve". There is a gap in the tube for the temperature probe, which is then wrapped in another cardboard sleeve. I hope this can simulate internal PV battery temps accurately.

Any concerns about this methodology? Or any additional comments about what the graphs should read?

P.S. the test above was at 5c, I can't personally claim that 5c is a "safe" load for the batteries in question. I personally believe that it will diminish the life of the cell, and prematurely degrade it's performance. This is why I don't consider it "safe". I would be more comfortable with a test of no greater than 4c. I am, however trying to comply with the requested testing methodology...

P.P.S not sure why the graph won't display at full size....here is a direct link
http://imageshack.us/photo/my-images/254/awlifepo4stack5c.jpg/

 

[AriM]

Clearly I am, as you have contradictied yourself as earlier you even said it was, quote, a "Pity" that we wouldn't publicly acknowledge and accept legal liability:



And you said:



And then when i asked you to take legal liability for your testing, you do an about face:




And:





Earlier, you clearly wanted us dealers to endorse and make legally liable statements , but now that it's turned on you, you won't make them about your testing. This shows a bias and agenda to me.

No, you still misunderstand what I am saying. I am saying that simply making a statement here on ECF "I personally endorse XYZ" is good enough. I am saying that no legal document with a signature is necessary. Please don't selectively quote or spin what I am saying.

I am willing to stand behind my statements and take full legal responsibility for them. I don't find it necessary to get a legal document saying so, however. It's that simple. I take full accountability, but I am not willing to spend money to have a document stating so drawn up.

I am asking that you take the same level of accountability, that's all. If you make a claim, stick to it. Don't differ and say "the manufacturer claims XYZ".

There is no agenda, other than trying to be as realistic about this as possible. I am willing to legally back a claim of 2c-4c. I am not willing to back any claim of 10c, or that such tests should be carried out on the batteries in question. I don't understand why you are finding a disconnect in that. If it makes you feel better, I just put up a test at 5c, which I can't endorse or claim as "safe", but it's what was requested.

Also, I clearly say that I am not about to back a claim of 10c. How do you not see that? I am not doing any about face at all.

Let's just let it rest, you have an mission to spin what I am saying/asking.

Why the mission to be hostile?

 

[forcedfuel50]

Fair enough AriM, You post up your results, i'll post up mine and let's move on.

To Recap:

AW LiFePO4 3.0/3.2V 16340 Results

AW's Listed C rating: 5C

I subjected them to Manufacturers C ratings and to max load ratings, way beyond what our ecigs draw. I tried to get 4 of them to fail by subjecting them to a 10amp continuous load (20+watts) and draining them down to zero volts. They reached 180F, but none of them failed or leaked.

If you have trouble viewing the graphs, they can be found here: Super T Manufacturing, Innovative manufacturer of electronic cigarette products.

5 Amp Continuous Load, Stacked Cells:

5 Amp Continuous load, Single Cell:

10 Amp Continuous load Single Cell (over twice their rated amps):

5 Amp Duty Cycle. 5 secs on, 20 secs off, Single Cell:

[/QUOTE]

 

[AriM]

That's all I am asking. Let's run the tests. Data is data. We can let ECF decide what is acceptable for the recommendation (Which is a form of legal claim, if we like it or not).

I personally give big kudos to ECF for being so brave and responsible. Also let's let our personal endorsements be exactly that...personal claims. Nothing more, nothing less....but let's just agree to have some accountability for what we put out there. That's all I am asking. Not trying to attack anyone, or instigate any misgivings.

I will personally endorse the data I provide on my own website, as you have done so (on your website). I don't think it goes beyond that really?

 

[rolygate]

I have opened a private forum now, down at the bottom of the forum front page.

Only FF50 and Arim have access.

It might be better if we moved there as we won't have any worries about endorsement etc. I can move the tests results across when convenient.

Thanks.

 

[AriM]

I have opened a private forum now, down at the bottom of the forum front page.

Only FF50 and Arim have access.

It might be better if we moved there as we won't have any worries about endorsement etc. I can move the tests results across when convenient.

Thanks.

Sounds good to me. I would be fine with all of my data/posts being moved to that sub forum.

edit : Roly I can't find the private forum...can you send me a link to the main page? thanks