Mech users, help me make upcoming battery shootouts more useful for you!

[Mooch]

For those of you who don't know me, I have been doing a bit of battery testing and safety grading of batteries (see my signature for the links). Based on the results of all the battery testing I have been doing I'm preparing some head to head battery comparisons of all the batteries at 10A, 20A, and 30A. But I need your help.

My existing battery test graphs go down to 2.8V to show the complete discharge of a battery. This makes it hard to compare different batteries because, at least for regulated mod users, the low voltage cutoff for the mod is up near 3.4V.

My head to head comparisons, "shootouts", will end at a voltage higher than 2.8V but I don't know what the typical mech user tries to stop at. Is it up there near 3.4V? Below 3.0V? Somewhere in between? Not the voltage you read when you take the battery out of your mod but the actual voltage under load. Tough to get that number sometimes, I know, but if anyone had info for me that would be great. And it would help to make the shootout more useful when choosing a battery to vape with.

Thank you!

 

[roxynoodle]

Using an inline volt meter when we are getting ready to change out our batteries?

 

[Mooch]

Using an inline volt meter when we are getting ready to change out our batteries?

That would be perfect. Not convenient in the slightest, I realize, but I was hoping that some mech users had done it at some point.

Or...occurring to me quite late...just letting me know what the preferences were for the lowest voltage on the shootout graphs would work too.

 

[roxynoodle]

I'll do it and write them down so I can post several. I've never checked them under load at the end of usage before. I use 18650s of 3 brands and 14650 Efests in two mods.

 

[Mooch]

Thank you, that would be incredible!

 

[caboog78]

I don't have an online meter, but my digicharger shows voltage when I pop them in. Usually, when using a mech, I see them at around 3.6 v when I put them on there. Purely anecdotal, I know, just swapping them when I'm not getting enough of a vape anymore, give or take.

Edit to add: Using Samsung 25r's with the blue wrap, and typical builds are .4-.7 ohms. 18350 style I use AW cells with 12A CDR and 800 mah capacity, builds between .8 and 1.1 ohms. Still not scientific, but extra data points in case they're helpful. Any thing to try and help Mooch

 

[Cullin Kin]

I used to take my Sony VTC4's down to 3.3-3.4V under load (3.5-3.6V not under load) in my FUhattan.

 

[Monotremata]

How do you guys know when to pull em?? I just ordered my first mech today, and Ive had my hand held with the cutoff of my regulated mods this entire time. Im assuming since theres no buck/boost circuits, you can tell a big difference when the power/wattage starts to go? My multimeter is in storage along with alot of my crap so I dont even have that or my Nitecore that does show me a batteries voltage to check with at the moment. I dont want have to use the 'wake up' feature of my Xtar anytime soon haha.

 

[B2L]

I haven't tested them with an inline meter to get the drop but, from others posts, the devices I run have voltage drop somewhere around .5-.75V. I find that when I'm changing my batteries they are reading generally around 3.7V.

Hope that helps, thanks for posting your tests, I've found them very useful.

 

[Cullin Kin]

I haven't tested them with an inline meter to get the drop but, from others posts, the devices I run have voltage drop somewhere around .5-.75V. I find that when I'm changing my batteries they are reading generally around 3.7V.

Hope that helps, thanks for posting your tests, I've found them very useful.

And agreed, his contributions to this forum and the vaping community are gold.

 

[DaveSignal]

I haven't tested them with an inline meter to get the drop but, from others posts, the devices I run have voltage drop somewhere around .5-.75V. I find that when I'm changing my batteries they are reading generally around 3.7V.

Hope that helps, thanks for posting your tests, I've found them very useful.

The voltage drop depends on the resistance. But your numbers put the battery under load at around 3V. I am also a mech user and agree that the mod is still vaping at this point, especially if this is still a high wattage given the amount of amps running through the circuit.

I don't think a whole lot of people here have experience vaping with a resistance drawing 30A. I have some builds that are close though. This is a lot of power, even with a depleting battery. If I would vape a load like this all the way until I no longer have a quick vapor response from the fire switch, the vape is noticeably weakened, and I am no longer enjoying the vape, the battery is about at 3.3 volt when placed back on the charger. This puts the voltage under load well below the 3 volt mark. Obviously, the most important battery output is at the start of the cycle, since this is where all mech users will be using it. But mech users can, and often will, run voltages under load well below what a regulated mod would cutoff at. On a mech with a low resistance atomizer build, below cutoff could still be more than reasonable amount of power. At the 3.4 volt cutoff for a regulated mod, a mech with a build drawing 30A is still putting out somewhere around 100 watts. This is a cloud-chaser wattage.

 

[Darth Omerta]

How do you guys know when to pull em?? I just ordered my first mech today, and Ive had my hand held with the cutoff of my regulated mods this entire time. Im assuming since theres no buck/boost circuits, you can tell a big difference when the power/wattage starts to go? My multimeter is in storage along with alot of my crap so I dont even have that or my Nitecore that does show me a batteries voltage to check with at the moment. I dont want have to use the 'wake up' feature of my Xtar anytime soon haha.

For me its a feel thing. A mixture of timing, and how the mech is firing. It has been a bit tougher for me to tell with my RDAs but that just makes me a bit more dilligent.

@Mooch ever since i got my first multimeter (about 3 months ago) out of curiosity I've been trying to test my batteries under load as much as possible. I usually pull them long before my actual cutoff of 3.4v but i think thats a reasonable expectation from a battery.

I would like to note that the multimeter i was using has been giving me some wonky readings for the last couple of weeks. I have been just using my nitecore and ohm meter for all my safety checks lately.

 

[Thrasher]

Above .5 ohms I usually get to the 3.4- 3.5 area. Under .5 I personally can go to 3v. I know the dropoff is a bit much for the average user but it doesnt bother me. But my .3 (.29 officially) ican can run em under 2.7 if im not careful.


I would think 3.3v bottom maximum would be suitable for almost all users

 

[Mooch]

I'm starting to think I might need to do two graphs for each shootout, 3.0V cutoff and 3.4V cutoff.

 

[DaveSignal]

If a graph with 3.0V cutoff has all the data plus some extra as compared to a 3.4V cutoff, I'm not sure why two graphs are needed. You could just have one graph showing all of the data. If you wanted to show at what point a regulated mod would cutoff, you could notate that separately. In fact, most regulated mods will never even draw 30A from a single battery. So, the high amperage tests are really most relevant to mech mods anyway.

 

[Mooch]

Good points!
I could just have an added bold line across the 3.4V point. Takes me about the same time either way.

The one big advantage for having a separate 3.4V graph for the lower current shootouts is that the capacity range can be reduced significantly, effectively zooming in and making it easier to read off various numbers and separate the plot lines. Reading the 30A graph is pretty easy. The 20A and 10A graphs will be quit crowded.

I think I might have to do prelims for the 20A and 10A graphs, perhaps 5 or 6 cells each. The best cells from each prelim would then all be put in one graph for the final shootout.

 

[caboog78]

Just so I know, instead of guess, your graphs are showing readings under load?

 

[Mooch]

Just so I know, instead of guess, your graphs are showing readings under load?

Yes, all my tests show the cell voltage as it is being discharged under load.

 

[caboog78]

Thanks for the clarification! 3.4/3.0 seem like really good spots to cut off then, especially for mechs

 

[Froth]

I'm certainly in the minority, I tend to push the limits pretty far so take that into consideration. All of my vaping use is at very low resistance and for the most part I tend to run batteries down to ~3.3-3.4V though depending on the day and where I am I do not have a problem running them to cutoff voltage. That said, the lowest I've ever put a battery on the charger at was 2.7V and that was a pretty tired 25R with many charge cycles on it and that actually never ended up reaching 4.2V with a 1.0A charge so I discarded that cell entirely. Numerous times I've put fairly new 25R's on my charger and had them read 2.9V and 3.0V, and those batteries are still happily working in my rotation with no noticeable weakness or loss of life. For what it's worth, the only battery I use is the blue Samsung 25R2.