I recently bought a few new wurkkos Diving lights (DL03 + DL08). These are coming with the original Wurkkos 5000mah 21700 15A batteries, but I’m trying to see what would be the best alternative for longer capacity, with a focus of UNDERWATER photography - i.e. the lights are constantly in cool water meaning they can maintain high turbo output far longer.
I am looking mostly into Vapcell models - I originally looked at the Vapcell F63 as its capacity noticeably higher, but I also noticed it’s only 12.5A, and while I can’t find amp ratings for these lights, other 21700 lights are known to draw up to 15A in turbo mode, even without water cooling.
So I’ve been wondering - am I better off maybe with the F52 which is only 5200 but 15A (though only a minor upgrade over the Wurkkos, but I still need spares). OR, maybe look at the T50 (which is a rebranded Samsung S50) which gives up to 25A and may perfrom better in longer high current draw, eventhough its only 5000mah?
(p.s. I’m also using TS22, and considering getting also a TS26, but those are used in a far less demanding way. For the DL08, especially, as it is a video light, I would like max capacity for relatively long durations).
Very interesting. I did not come across it at all in my searches. this looks actually like a very interesting battery.
According to Mooch - it will outperform the Samsung 50S (/Vapcell T50 which is a wrap) up until 10A, but the 50S/Molicells will outperform at >10A.
I don’t really have the amp rating for the dive lights I want to use it for, but I have a strong feeling that the a 3600lumens wide beam (4xTN-3535 driver altogether) single 21700 batt should draw more than 10amp? WDYT?
I think I remember reading a good explanation from @Mooch about not solely focusing mAh capacity, certainly at higher amps, because it doesn’t tells the whole story. The discharge curve/voltage sag (over time) are also an important factor which also influences the actual runtimes.
Unfortunately I can’t find the post from Mooch, that I think I read (it might have been on the E-cigarette forum), so I can’t link you to it.
I don’t know where you live, but if in Europe: you can currently pre-order the Reliance RS50 that @mickey10632 mentioned at Nkon. They also have the EVE 50PL on pre-order, which should perform similarly and is a bit cheaper.
You’re right.
At anything over a couple of amps the (“nominal”) capacity rating starts becoming less and less useful. Especially if you are not running down to 2.5V, which no one does.
At higher voltage cutoffs and a few amps you might only be getting 70% of the capacity rating actually delivered by the cell…the rating is useless.
The Wh of energy delivered by the cell is the best indicator of how it actually performs since it it is Ah * Voltage. It takes run time and voltage-under-load (voltage sag) into account. My “E-Scores” (energy scores) are actually the Wh delivered down to 2.8V.
This makes direct comparison of different cells at different current/power levels easy to do.
this is not for vaping, its for a Skilhunt H300 flashlight that uses 18650, intended for backcountry night skiing in an area whose lowest temp last year was -14C
focusing on low temperature performance, would you choose Molicel P30B 3000mAh rated to -40C, or the Liitokala 4000mAh, or Vapcel N40 4000mAh that are rated to -20C?
A lot of cells have discharge temp ratings down to -20°C but the performance will be TERRIBLE long before that low temp is reached. So it’s technically possible but the voltage sag will be huge and the run time short.
I’ve done almost no purely vaping-related testing for a long time but it wouldn’t matter as the cells don’t care what they’re used in, just how they’re used.
The ambient temp and the cell temp can be very different and that’s what can make cold weather use possible. If the light is kept at around room temp (under your coat) and you start using it at this temp then the cell might never get cold. The discharge will create a bit of heat to help “hold up” the voltage.
It all depends on the cell, how much current you’re drawing, how much the cell is thermally coupled to the light’s case, etc.
Without a doubt, the Molicel. They’re designed for cold weather performance and the others are not. This does not mean the Moli will have the same run time at -14°C as it does at 25°C though!
It just means that it will have better cold weather performance than other cells.
The Moli will also hold its voltage up a lot better at moderate to high power levels (at any temp) than those other higher capacity cells. Ultra-capacity cells can’t deliver that extra capacity at levels above a couple of amps and only if you go down to below 2.8V-3V.
Thanks - I’ve been reading your reviews and looking at your comparison tables. With that it seems that the EVE 58E is better for my flashlight needs vs a Samsung 50S (albeit the diff isnt huge). It also seems the Vapcell F63 might still outperfrom them in a flashlight not exceeding 10A, but it’s hard to tell (plus the F63 is wider and may not fit my flashlights…)
So first of all - thanks for all the data you’re sharing! I’ve learned a lot from reading this.
I was wondering, however, what does “e score” represent? is that actual Wh being usable from this? or any other scale?
Thank you very much! The reality check is very much appreciated.
I follow your reasoning on the difference in performance of a light carried near a warm body, as opposed to in an emergency kit in a backpack (which will be closer to Ambient temp)
thanks also for the comment that performance depends on current draw.. the H300 draws 4.5A on Turbo..
my takeaway is the Molicel P30B is still King of the Roost when it comes to my backcountry night skiing application.
As mentioned on the E-Scores table, they are the actual delivered Wh at the indicated current/power levels down to 2.8V. The ACTUAL energy delivered by the cell, not a theoretical rating.
They can be used to directly compare the actual performance while under load for any cell on the tables.
So I went back to look at your tables.
At seems the Vapcell F63 will (ever so slightly) outperform the EVE 58E up to 10Amp, which is what I expect a single-21700 batt to be able to draw, even a turbo mode.
The F63 gets 19 for 5A and 18.2 @ 10 Amp, whereas the EVE E58 does 18.4 & 17.9.
Is there any other reason to prefer the EVE over the Vapcell?
(I noticed the Vapcell has slightly higher resistance so it may heat more in general, but in the water this should be a none issue).
Perhaps cost and/or cycle life but we don’t know the actual cycle for either cell. If you’re considering a large purchase I recommend testing both cells to see which might be better for your particular application.
Not a big enough purchase. I need maybe 6-8 altogether. I may try though to split the buy between the EVE and the F63 and then try - this way I will know which one is my primaries and which are the backups - OR, find out one is more suited for one flashlight over the other (there’s a video light and a regular flashlight, they may require different current)
Very hard to test all in all though I assume at the bottom line, both the EVE and the Vapcell would be good with minor diff between them and both probably noticeably better than the 5000mah Wurkkos branded 10A max battery that comes with the flashlight (which will be the backup of the backup…
