Bench Test Results: Vapcell F60 - 12.5A 6000mAh 21700

Batteries and Chargers Rechargeable Batteries
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These tests below only note my personal opinion for the ESTIMATED ratings for the batteries I tested at the time I tested them. Any battery that is not a genuine Samsung, Sony, Murata, LG, Panasonic, Molicel, or Sanyo can change at any time! This can be one of the hazards of using “rewrapped” or batteries from other manufacturers so carefully research any battery you are considering using before purchasing.

Misusing or mishandling lithium-ion batteries can pose a SERIOUS RISK of property damage, personal injury, or even death. Never use them outside of a fully protected battery pack and you use them at your own risk. Never exceed the battery’s true continuous discharge rating (CDR), never let it get colder than 0°C or hotter than 60°C, and keep the plastic wrap and top insulating ring in perfect condition. Never use a battery that is physically damaged in any way.

Testing batteries at their limits is dangerous and should never be attempted by anyone who has not thoroughly studied the dangers involved, understands the risks, has the proper equipment, and takes all appropriate safety precautions.

If the battery has only one current rating number, or if it only says “max”, then I have to assume the battery is rated at that current level for any type of discharge, including continuous.

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Test Results

This is a very good performing cell but others are a bit better. It’s one of a new generation of ultra-high capacity cells that has recently become available and is definitely worth considering if you can get it at a good price. I don’t know what cell Vapcell is wrapping here but it’s probably the FEB 21700-60A or Lishen LR21700SS.

  • This cell ran for the same amount of time at 5A and 10A as the BAK N21700CG-50.

  • The LG M50LT and Samsung 50S ran for a bit longer than this cell.

  • This cell ran for a bit longer than the Molicel P45B at 5A but the same at 10A.

Like any ultra-high capacity cell, if you want to get the full capacity from it you’ll need to run it at a very low level…under 2A-3A for this cell.

This cell’s 12.5A rating seems reasonable. The two cells I tested delivered 6065mAh and 6087mAh. This is good consistency and meets this cell’s capacity spec of 6000mAh.

This is a larger cell than some, both were 21.6mm x 70.9mm.

Continuous Current Discharge Graphs

Vapcell F60 - 12.5A 6000mAh 21700 CC Tests
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Ratings and Performance Specs Graphic

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18650 Ratings and E-Scores Table:

20700/21700 Ratings and E-Scores Table:

To see how other cells have tested check out this link: Links To All 21700, 26650, 18350, 18500 Battery Tests | E-Cigarette Forum

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Thank you for your review!
I am quite interested in very high capacity 21700 cells. :slightly_smiling_face:

I wasn’t aware of this information. :+1:

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Thank you Mooch for the review, I didn’t know they lost so much capacity with a bit of power, but that’s still >500mAh more than most cells at 5A.

Have you also tested the Vapcell N40 and F38 18650s? Very interested to see how they compare to “classical” 3.5Ah cells like the 35E, M35A and MJ1.

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Yes, both.
Since they are wrapped by Vapcell, and can change at any time, they are not in my Ratings & Performance table. But my Mooch FB page has posts with the Ratings Graphic that has the E-Scores. You can compare those scores to the other cells you mentioned if I gathered that data (not sure, check the table).

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These 6000 mAh cells seem nice. I don’t use much power, so it would increase my torch runtime from ~50 hours to ~60 hours per charge.

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Is this data anywhere other than FB for those of us without FB accounts?

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Which data? This is the full test report for this cell.

But for other cells the test report above has non-FB links to the Ratings & Performance tables and a link to all the other data. The master list of reports though is regularly screwed up by that web site (ECF) so you might have to search for the report using the cell model number and my name there, “Mooch”.

Everything on FB just links back to the ECF forum. Some day I’ll get it all ported over to my own site.

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That’s where most 1x21700 flashlights end up after they thermal throttle from their highest mode. This looks like a great cell for sustained use in flashlights and headlamps.

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I’d love to see more high-mAh cells like this, with longer runtimes at the practical medium and low levels a small torch uses. On most EDC-sized lights, the entire bottom half of the ramp is well under 1 Amp… and I find the 5 to 50 lumen range is most of what I use. So I go for cells with the longest runtime at ~100 mA.

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For those people thinking about using this cell in a D4K / D4V2 with boost driver, I have a warning. This cell is the same size as the Vapcell F56 which is about 1mm longer than average. I am not comfortable putting the F56 in those lights (they have already crushed standard 70mm cells). I’m interested in hearing other people’s experience though, for those you of you brave enough to try it :wink:

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One option could be to shorten the tailcap spring a bit, maybe cut off a coil from the head spring too. I’ve read of people doing similar things to the D2 to make it fit slightly-too-large cells.

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Thanks Mooch!

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So it’s a Lishen LR2170SS? For now anyways.

I don’t trust these ultrahigh capacity cells. Not for flashlights anyways. Too much heat in a flashlight for these ultra high nickel, ultra high silicon electrodes. And I know everything over like 3000mAh has some nickel and probably some silicon but for some reason these ultrahigh capacity ones seem extra sketchy.
Like, thermal runaway has been triggered at temperatures as low as 75°C and SoC’s as low as 75% on some ultrahigh nickel cells. That’s wild.
Put them in EVs with liquid cooling if you want but a flashlight? Idkk

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Did Dennis confirm it was a LR2170SS (vs FEB 21700-60A)?

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AFAIK, we don’t know if it’s the Lishen, the FEB, or possibly another cell. Everyone is working on the >5500mAh 21700’s, BAK’s is probably the next one coming along as they have just started full production on the 58E and are working on their 6Ah cell.

Where have you seen this? I’ve taken hundreds of NMC cells over 120°C without problems. And standard UN 38.3 high-temp tolerance testing holds the cells at, IIRC, 130°C for a decent amount of time (an hour?).

The NMC cells typically used now are already 80% nickel and won’t go into runaway until way over 200°C. Even LCO cells are typically not going into runaway until you’re up near 130°C.

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I read this one recently, they did a pretty good job I think.
Thermal runaway aspect of ultrahigh-nickel cathode-based lithium-ion batteries at increasing charge states- Journal of Energy Storage, 15 January 2024

This quote by Jeff Dahn scares me- “NMC811 will be very difficult to make safe in Li-ion cells.” because he’s not even referencing ultra-high nickel cathodes here, and this was before they started using silicon.

To your points, my thinking is that SoC is very low and getting lower by the time they reach that temperature during your discharge tests. In a flashlight though high temperatures can be reached pretty quickly while still at a high SoC.

UN38.3 thermal testing heats cells at a rate of 3.83(odd coincidence lol)°C/min, and faster heating was shown to be a factor. The above study went as high as 15°C/min, but that’s still slow compared to some flashlights that are closer to 15°C/second than per minute.

But Im skeptical of everything that seems too good to be true lol. Maybe I’m way off. Thanks for review btw

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We have to be careful when trying to apply their ultra-high-nickel (88% + 91%) results to the high-nickel (80%) cells we use. There was a considerable difference in some metrics when just going from 88% to 91% so our 80% cells will be a lot less volatile then those cells. This is borne out by the verrry low failure rate for standard NMC811 cells.

They also took samples from cells and formed them into the shapes they needed and sealed them in their test oven fixtures. None of the tests of these cathode materials was done with standard round cells. This is critical!

The cells we use quickly pull heat away from the hot spots that form in a cell. Even if the entire cell is heating up its operating environment pulls heat from the cell. This helps keep the exothermic reactions that start at about 75°C from increasing the cell temp unless there is a LOT of that heat being created, like during a short circuit. For many uses the heat flowing out of the cell keeps it from getting anywhere near the temps required to initiate thermal runaway.

The exothermic reactions start at around 75°C, not the thermal runaway (TR) event itself (decomposition of the cathode material, smoke, fire, etc.). This is true for all li-ion cells and not just the ultra-high-nickel ones.

Cathode decomposition, which can lead to TR, starts up at around 180°C to over 200°C for the NMC811 cells we use.

Regarding TR occurring at 75% SoC…TR can occur at any SoC. It just gets harder the lower the SoC. Which makes sense and is true for any li-ion chemistry. Higher SoC = more energy. The cells we use, and even those ultra-high-nickel cells, don’t suddenly become dangerous at 75% SoC. They all just become more likely to go into TR if abused as the SoC rises.

The heating rate has an effect for any li-ion cell but isn’t some kind of guaranteed TR trigger. It’s just a part of the large number of things that can increase the odds of TR occurring if all the other conditions are right. Fast heating on its own can’t do it.

I’ve discharged lots of 18650 and 21700 cells at 100A, raising their temps at about the highest rate possible except for a hard short circuit, and all were at 100% SoC at the start. Some were even wrapped in insulating cloth. None went into TR.

Why not? Because the other conditions necessary for TR weren’t there, in particular, cell temp. We just don’t have to worry about the rate of heating on its own.

We have no context for his short statement and it can’t be used as some sort of general statement. What does he mean by “make safe”? Hundreds of millions of NMC811 cells are in use every day without problems.

Is he developing a different chemistry cell? Does he have a financial interest in making NMC811 seem dangerous? He’s a brilliant researcher and has done some incredible stuff but the details surrounding his statement matter here.

Considering the very long and incredibly widespread use of NMC811 cells I don’t think we have to be scared of them. Just treat them with respect for the power they contain, like any li-ion cell, and we’re fine IMO.

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thanks for sharing these info

for the typical flashlight enthusiast running high amps with no ATR, it should be “safe” even with temp of flashlight and battery hovering around 80-90 degC ?

to be “safer”, I only bought those more known/recommended cells like moli, sanyo ncr, lg mj1, samsung 50g etc

haven’t seen video(s) of a thermal runway in a flashlight…with this enclosed container under high pressure, I wonder what will burst 1st…maybe the lens?? exploding shard of glass…

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I didn’t mean to sound so dramatic lol. Let me rephrase that…

I thought they said that initial reaction could potentially provide enough energy to trigger further reactions all the way up to TR in a ultra high nickel one maybe sometimes. No? I could be reading it wrong. I’ve done it before.

You know what…I just realized that might not even be his quote lol. It’s from his research group but I don’t know that he actually wrote that. So that’s not fair of me to assign it to him.

You don’t think these 6000mAh cells are already >80%? I don’t know that they are, Im just assuming thats the direction we’re going. Where else could they get are they most likely to get that extra capacity? More silicon? But that’s not any better.

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Not even remotely safe. :slightly_smiling_face:
At roughly 75°C the liquid inside the cell starts to decompose and exothermic reactions begin. If the cell can’t get rid of this heat then you can eventually force the cell into thermal runaway. This can burst the cell and cause a fire. This is true for any manufacturer’s li-ion cell.

But this doesn’t mean there’s a bomb in your light. A lot of this heat is pulled from the cell as it’s created and that can prevent the cell from catching fire. But the hotter you run it the riskier it is. There’s no way to quantify the risk though so all we can do is advise not to do it and, if done, to be as careful as possible.

This is completely ignoring the hugely speeded up aging (damage) of the cell, which I’m assuming isn’t much of a concern.

If it’s anything like the “mech” vaping devices the gas pressure will bulge out the tube, disengaging the threads, and explosively separate the two parts. The hot gas and flames will exit every possible point they can though.

A high capacity cell can release up to 10 liters of gas in runaway and this can make for some verrrrry high pressures in a “pipe bomb” like a light or “mech” vaping device.

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