What is the best high capacity 18650 battery?

Interesting thread, even if it left the OPs original question behind 2,5 pages ago!

What seems to account for the varying specs from different manufacturers is whether they state “minimum capacity, ”typical capacity” or “maximum capacity”.
Furthermore it is probably also affected by which bins that get available for “hobby users” as single cells.
If all of the “A binned” cells go to battery pack manufacturers, and all we are getting are the lower bins, more variance in internal resistance and capacity is a given result of this.
This is something that will vary, not only between different manufacturers, but also between cell models, as they are adopted for different packs by different makers of such.
Yet another factor is how exact the manufacturing process is for different brands and models, ie: what portion of every batch ends up in which bin.
This may also vary from batch to batch.

(A good example from another, yet somewhat related, manufacturing is CPUs and GPUs. Where certain models and batches turn out so well that the ones sold with lower specs, which is typically where lower bins end up, are really all from the highest bin and just underclocked. Making some extremely reliable for and sought after by overclockers. Nowadays though, most are made like this, and the makers of CPUs and graphic cards have gone to great lengths to lock the lower spec products from overclocking and unlocking disabled cores and whatnot).

When it comes to “real world performance” the variation is a lot more due to what the individual user actually uses something for, and how.

I, for instance, use a D4 with quad 219Cs. On top of that, I mostly wear a suit and want my EDC to fit in a vest pocket, so about 10cm/4” is the longest anything that will fit properly.
Hence, I use a shorty tube and an 18350. (Just got myself five Keeppower 1835Ps for that and there really aren’t any competitors in either output or capacity in that size. Except other brands using the same cell).
I do however want the ability to screw on the long tube and get maximum performance and/or runtime with 18650s.
If I go “glamping” that includes a generator (and a PA system plus a bunch of DJs etc) in which case I can always charge my batteries. And if I’m bringing a vanful of gear anyway, I can also bring all of my cells…
If I go camping/hiking/biking/kayaking though, I’ll need to bring lots of spares and/or use the ones with the most runtime, given the way I use the light. This also applies to when I go to open air techno parties and don’t want to bring more than a small bag, yet might be away for the entire weekend.

Now, I haven’t owned the D4 long enough to really know what my “real world usage” really is. And summer “nights” here in Sweden consists mainly of dusk and dawn, never really dark.
When “glamping”, or in other words, arranging and crewing a 48h open air techno party on a small island, an efest 18350 lasted all Friday night, when I was actually working and used it at lower output to see what I was doing close up. On Saturday night though, I quickly “drained” a VTC6, and thought that the flashlight got a lot hotter a lot quicker. Although by then I was properly F’d up and mostly just having fun with my pocket sun! :smiley:

My actual question:
The problem with such a compact and high power build as the D4 though, is that regardless of how well the battery handles high current, or perhaps even exacerbated by it, the emitters will get extremely hot in a very short time.
The worst case scenario though, would likely be with a cell that is just about able to continuously deliver the maximum current, as pulled through the FET by the low fV Nichias, while itself heating up quickly!
This is probably the case with the Keeppower (Yongdeli) 18350s, and in all probability with all of the high capacity “10A” 18650s as well.
I’ve read somewhere on this forum that the draw is somewhere around 16-17A on turbo.
For most applications, such as lighting a dark path or for close up work, I’m fine with the “highest” regulated level, ~150lm @350mA. And while the ramping interface is nice and allows for finding the perfect power level for any given need, I very much like to just “Let there be Light!” with a double click, and then get back to low with another.

So the question is: what will be the sweet spot in batteries for the ability to run it for a long total time on low while retaining the ability to also use turbo, preferably for somewhat long durations, given the restraints of the compact build and its inherent heat problem?
We do get really cold winters here in Sweden as well, but I’m not worried about that as I trust in the heat build up to take care of that. Based on lots of experience with a TrustFire light running both TrustFire and Sanyo 14500 cells. (Had to occasionally start on low, but never failed completely unless cell was already very low and temp below –15°C (toward 0°F).

I’ve already got a couple each of VTC6 and HG2 and plans to get a couple of 30Q and probably GAs as well while I’m at it, for further single emitter lights if not for the D4, where I do believe that they are still top dog.
Price really isn’t an issue, not because I print my own, but because I won’t be needing that many and won’t wear them out for years…

And lastly…
To really put the “High drain Vs High capacity” question to the test: (leaving 18650 size)
How about comparing the A123 26650, just 2500mAh, but LiFePO and rated at 70A continuous output, to a good 26650 cell with at least double the capacity, at a discharge level around what the other cell is rated for?
The voltage at which the high capacity overtakes the A123 might be a bad indicator as it’s a LiFePO… but still, sometimes looking to the extremes is the best way to determine the answer to a question where the difference is too small to be decisive!
And might be interesting for the D4S. :wink:

Just got in three 36G and here’s a comparison of them with a couple of now 2-year-old 35E cells. I am not impressed. Avg 2% higher capacity. Temp 32-34C through the run, had a fan a few feet away. The edge cells #1 and #4 were held in at the top of the bays by spring tension and the center cells #2 and #3 had magnets (those are the two ways to deal with too-flat flat-tops in the MC3000).

This was a 750mA discharge to 2.8V after a 4.2V charge to 90mA. I usually measure capacities a bit lower than rated, but pretty sad showing for the new cells in comparison. Not sure if it’s enough to complain to the supplier, but I’ll probably send them this as a FYI. Subpar batch? Normal variation between cells?

For use, they’re fine, as good as the other 3500mAh, but vs not-fresh 35E cells I would have liked to see better. Got them on sale $5 ea from 18650batteries so even with $5 shipping didn’t pay a premium. The 35E were from Banggood 9/2016 at $7ea. The 36G have circular indents on the bottom, which I hear is normal (extra safety “vent”).

Text version:
36G #1: 3195 mAh
36G #2: 3287 mAh
35E #1: 3184 mAh
35E #2: 3174 mAh

How many times were they cycled?
Were they all discharged and recharged by the charger?

Couple of times each (by the MC3000) when I got them a few days ago, same for the 35E two years ago (they saw very little flashlight use if any, stored at 3.7-3.9V). Just ran the 750mA test on these 4 tonight discharge maybe an hour after charge completed. Usually test at 500, but wanted to see a result before bed.

So for new cells 2% isn’t bad, 36/35=~3, and really, I don’t see a lot of capacity loss with storage, but 1 would be my guess. I have original Panasonic Bs that lost maybe 2-300mAh over many many years. Lot less than the calendar life data I see published.

Just looked at the 35E datasheet and they’re min 3350mAh with a 2.65V cutoff at .2C with C=3400 (not 3500). Can’t find a 36G datasheet yet but I presume it’s similar. FWIW, maybe nothing, the DC IR was about 55mohm for the 36G vs 45 for the 35E, but take MC3000 IR measurements with a grain of salt. I see 30-45 for 30Q/VTC6/HG2.

Maybe the improvement is mainly less voltage drop under load, hence the 10A rating instead of 8A?
This would mean the cell has higher Wh but that would not be visible form looking at mAh, a discharge graph like the ones from HKJ would be necessary.

So as far as capacity goes, they’re pretty much the same as the 35E, right? I think that’s what we were all predicting. How is this in any way sad?

Have you compared their internal resistance?

Have you measured their current output using a FET based driver?

Are they rated at 10 amp continuous? I haven’t seen any data sheets for it.

Edit, I guess datasheet aside, the stores are listing it as a 10 amp continuous cell. So that must be where the Improvement is.

I0A CDR rating vs 8A, yes. I wouldn’t pay extra for the 36G but then, I didn’t.

Argh, the MC3000 does Wh but the result is buried and I didn’t record it. I can rerun the test later but the next day or two I’m topping off 50 or so cells in anticipation of the hurricane (NC, USA).

No plans to do a FET driver test, they’ll be used in Zebralight SC600w MkIV Plus and SC64w primarily. I have a handful of budget lights, one of them probably FET, but all I’m sure of is most are 7135. Emisar D4 (XPG) OTW, that’s FET I think.

Hey… if you think the minuscule run time increase you ’might see’ is worth the price of getting new batteries…… I say go for it & let us know how it works out. :+1:

I mostly got them both out of curiosity and because it has been two years since I got the last batch of batteries. Got two VTC6 and another GA from ZL few weeks ago, three 30Q since they seem like good ones to have (I do vape some, and the SC600M4 can pull 8A), so a few 36G, especially on sale, seemed like a good addition. 1-2%, if it’s not more money, and rated 10A, what’s not to like… Figured if they’re new for 2018, they’ll at least be sure to be fresh cells. Now, if I get any other 3600, that’ll be purely for curiosity. Eight this-year batteries is more than enough. The Anker 10Ah power bank also makes using a few for USB purposes less likely.

Update after some 2A discharge runs:
36G#1 3145mAh 11.164Wh
36G#2 3143mAh 11.167Wh
35E#1 3111mAh 11.065Wh
35E#2 3121mAh 11.088Wh

So at best .1Wh or <1% increase. Vs brand new 35E, probably no increase.
Conclusion: you’re buying 10A vs 8A CDR, and maybe at HKJ’s 5 or 7A load the 36G will have a more apparent advantage, but at 7A the 3000mAh high drain versions, so far, always seem to win out.

Cool, thanks for the info.

Test results for the 36G from 18650batterystore.com on my Xtar VP4 Plus Dragon charger.

3454, 3385, 3427 3463, 3328. The average is about the same as the 18650GA. I think charger tests at 1A.

There’s no freaking way this cell is 3,600mah. Also this cell has a recessed top (not flat) so I needed to weld solder blobs inorder to even charge them on my charger.

I think the capacity of the 36G is supposed to be pretty much the same as the 35E, the big difference being a higher continuous amp draw. 8 to 10

As expected the real world capacity is always less than the manufacturer rating.
I think the only way you can get close to the manufacturer rating is by discharging at like 0.1A or something ridiculous.

Quite disappointing results for the 36G from Thunderheart LG M36 vs Samsung 36G capacity test .

Of course, since he only tested one cell the results are not very reliable, but at anything but low current the results he got for the 36G are worse than his results for the LG MJ1 .

There's something wrong with that test for sure, even the 35E outperforms the M36.

https://lygte-info.dk/review/batteries2012/Samsung%20INR18650-35E%203500mAh%20%28Pink%29%20UK.html

https://lygte-info.dk/review/batteries2012/LG%2018650%20M36%203600mAh%20(Cyan)%20UK.html

You seem to be jumping to one of two conclusions. Either the test is inaccurate or the 36G it’s just not that good of a battery.

Thundheart says that the store Queen Battery did their own test and decided not to sell the 36G because of it’s reduced performance.

It seems odd that Samsung would release a battery that didn’t actually perform better than its predecessor. Who knows, maybe more tests need to be done.

Why would a newly released battery from the exact same brand with a higher current rating and higher mAh rating perform worse than the 35E?
As I said earlier, the 35E outperforms the LG M36 (at lower currents, the M36 is better at 5A+)

Earlier in the thread someone tested their 36Gs and found that they were almost identical to the 35E, only slightly better.
Maybe this reviewer got fake or reject samples or something like that?

Often, but, for example, I just tested the XTAR 2200mAh high drain and got near 2300mAh. Not sure that’s ever happened for the 3000+ rated cells, I think I got 29xx for most of those. With 2600 and below I’m often pleasantly surprised.

I’d say 20-30% of the 18650s I order are like that. It’s still a “flat top,” and if a charger can’t make contact I blame the charger (and use a little magnet).

Chargers vary. Some have a full-length flat contact from the bottom of the bay with no protrusion to contact the battery. The MC3000 accommodates AAA to 26650, so it’s just a compromise I accept. The XTAR MC1 Plus contact, in contrast, sticks out a bit and can deal with it. The fully flat contacts also aren’t as safe, since, if there’s any flaw with the edge of the wrap, they could bridge outer shell to top contact. Not that you should use a cell with a flaw in the wrap at all…