26650 Batteries

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Great. Just picked up a 26650 flashlight at a great price… and maybe now I know what it was such a good price. I didn’t know 26650 batteries were a thing of the past. I was wondering why I have had a hard time finding decent protected 26650 batteries. :person_facepalming:

Good thing it can also use 18650 batteries… but with a substantial loss of mAh capacity.

Is it a single cell flashlight or multi cell. Single cell lights often don’t need to be protected. 26650 batteries are not a thing of the past many newer batteries have been produced. High capacity up to 5800 mah to very high amp out put. Let us know what light you picked up and will find you the best battery for it.

I was going to bore out an old 2×C light to take a 26800 and spacer, but 2 LFPs would allow better LVP if tweaked for that.

LFPs have a constant voltage over most of their SOC, so you could even cut it off at 3.0V/cell. Then even if freakishly mismatched, one cell might still be 3.2V but the other would be a nice safe 2.8V.

Definitely not a thing of the past. Particularly in 2S config, imo.

Buy these

I have three 2x26650 torches with a fourth on the way. None of them are protected. Haven’t had a problem in three years.

I have a range of different brand cels, can’t find most of them available to Australia anymore, the most recent ones I purchased are Vapcell 18.16€ |Original Vapcell 26650 4200mAh 32A li ionen batterie hohe kapazität akkus für taschenlampe Power Werkzeuge freies verschiffen|Wiederaufladbare Batterien| - AliExpress & Page Not Found - Aliexpress.com

I’ve got these two on my wish list 16.78€ |VapCell INR 26650 5500mah 20A Li lon Batterie Hohe Kapazität 3,7 V Wiederaufladbare Zellen Für Taschenlampe Power Tools|Wiederaufladbare Batterien| - AliExpress & 16.78€ |Freies verschiffen VapCell batterie INR26650 5300mah 20A G53 19,08 Wh 3,7 V wiederaufladbare 26650 lithium batterien für taschenlampe|Wiederaufladbare Batterien| - AliExpress

It takes two 26650/ batteries. I picked up the Wurkkos TS70 from Amazon for $50 the other day. I’m pretty sure the 26650 batteries that came with it are unprotected.

I’m still pretty new to the Li-ion battery scene, and recently picked up a couple smart chargers along with some Panasonic 18650ga 3500 mAh 10A batteries (intended for a Convoy S2+ (which I just received) and a Convoy C8+ (still inbound). I also recently got a Wurkkos FC11 and really like the ramping UI. But I digress. This is still all pretty new to me.

Well, reading this thread, that was the conclusion I came to. Glad to hear the 26650 is still around. But where to find protected cells (from a reliable source)?

That’s actually not a bad option. I don’t have any 21700 cells right now, and the Wurkkos TS70 came with a couple 18650 converters, but I’d like to not loose the capacity the 26650 batteries provide. Perhaps the 21700 would be acceptable? Or maybe I just need to buy another flashlight with 21700 batteries and then I’ll have that option too. :wink:

Lol! Maybe there’s still life in the 26650 line! The stock 26650 batteries I got with the TS70 were 5000 mAh. Here in the USA, I know of 3 trusted suppliers and their battery supply is LOW. No 18650 Samsung 30Q that I can find, etc.

Maybe I don’t need protected batteries, but I have a lot of respect for the damage they can do and feel better having protected cells in the house and car.

Your light on turbo is going to draw about 10 amps. 21700’s protected are probably going to be too long to fit. Shockli IMR26650 5500mAh and Vapcell INR26650 5500mAh (Red) both use the same cell as does the KeepPower P2655C 5500mAh Protected Flat Top which has a 10 amp cut off pcb. Any of these three would work provided you don’t exceed that 10 amp limit on the protected cell. The core is the Power Long Battery (PLB) INR26650-55A 3.6V PowerLongBattery (PLB) INR26650-55A 3.6V 5500mAh 11A 26650 Flat Top Li – Liion Wholesale Batteries These are also the preferred cell used by many here including myself.

Thanks for those suggestions. Yeah, I didn’t think about the greater length of the 21700 cells.

Is there a spec sheet somewhere that would tell me the current draw on the brightest mode? Seems that would be important info to have on any flashlight.

I pulled up the Wurkkos TS70 review and output. 5500 lumens from a 6 volt Cree XHP70.2 is about 10 amps. This may help as the LED is driven past the Cree charts LED test / review - Cree XLamp XHP70.2 P2 40E (4000 K) - The second generation of extreme overcurrent and light flux capability?

Thanks. I’m not quite sure how to read the charts, but I saw this from the review you linked. Curious how that factors in…

“Overcurrent:
20 Amps lab power supply maxed out!
possible light flux maximum not reached at 20 A, 9,228 lm @ 7.29 V at 20 Amps
power at maximum 145.8 W
Sweet Spot at 15 A (8,379 lm @ 6.95 V)
power at sweet spot 104.3 W
efficiency at maximum 63.3 lm/W
efficiency in sweet spot 80.3 lm/W

I define the sweet spot as the position in the diagram which gives a good average between light flux, current and efficiency. In most cases it lays roughly 15 to 35 percent lower than maximum possible light flux.

The XHP70.2 is so powerful that my new power supply (20 A @ 30 V max.) limits the maximum possible current in this test. The maximum should be reached at 21 to 24 amps, at approx. 9,300 to 9,500 lumens. LED will be consuming 170 watts!”

Your light is claiming 5500 lumens really probable 4500-5000 lumens from other good quality lights of the same format “XHP70.2, 2-26650 batteries.” With a good power supple and ample heat sinking it could be brighter. Given internal battery resistance, voltage sag, electronics resistance, LED resistance, heat you hit a ceiling. Now it’s a good light and it’s weight will do well to keep that brightness up there. A smaller light would heat up quicker and that also reduces brightness quicker. Wurkkos TS70, Convoy L6, Sofirn TK70 and Thorfire S70 are the top tier.

QFT! What about SP70?

Haven’t played with that one. From reviews I thought it’s a larger reflector version of the TK70.

What I was attempting to ask is about the fact he maxed out his 20A power supply vs using 10A batteries. Are you saying the ceiling limits the current draw? (I have the hots for an L7 now too) Hoo boy.