Author Topic: Shift from 18650 to 21700 (Read 4783 times)

lightknight · « **on:** March 12, 2019, 08:54:09 AM »

Hello Everyone

I am new in this forum and have already a question.

Do you know why many flashlight producers slowly start shifting toward 21700 types instead of remaining on 18650?

I know that 21700 have more possible capacity than the 18650 but are there any other profits?

Glad to hear your opinion on this subject.

macka17 · « **Reply #1 on:** March 27, 2019, 04:37:53 AM »

Different people think different ways. on all items.
Myself. I use 10440/123A 14550 18650 26650 etc.
But never got to like or use the 2000/21000 series.

I can't honestly say they worth even looking at. Basically TOO similar to the 18650.
It's just dealers/mfg's trying to make another segment of a small market to have "some" people buy a few more battery's.

18650 cover MOST of the hand held electrical output market.
SOME (A LOT) find them a bit skinny in the hand to hold. whereas the 26650 fit much more comfortably.

The 21000 ser are NO thicker. to hold. with only a slight capacity advantage.
Why. Really.... Bother?.

mtnbst · « **Reply #2 on:** April 07, 2020, 05:48:36 PM »

I'm noticing significantly longer run times with 21700 vs 18650 especially on medium. Ex... olight heat seeker 2pro, 300 lumens (9.5 hours) not bad....

JohnnyMac · « **Reply #3 on:** June 17, 2020, 10:56:43 PM »

To me the 21700 are brilliant. With the new super high output pocket monsters available, the 21700 offer the capacity of a 26650 with just the slightest increase in size over the 18650. Compared to 18650 the 21700 offer greater capacity, higher output in amps (40A or more compared to 20-30A at best, and less voltage sag. Everything Macka17 lists as a negative I only see as a positive. I have a lot of 26650 lights and I edc none of them because they are too fat to fit comfortably in my pant pocket.

My S2+ is a regular edc choice for me but I want an S21 in a bad way because it is only slightly thicker and at least 50% more capacity than the 18650 in my S2+. I say get used to the 21700 because it’s likely here to stay and for very good reason.

randomuserperson · « **Reply #4 on:** July 23, 2020, 12:50:26 PM »

Quote from: macka17 on March 27, 2019, 04:37:53 AM

Different people think different ways. on all items.
Myself. I use 10440/123A 14550 18650 26650 etc.
But never got to like or use the 2000/21000 series.

I can't honestly say they worth even looking at. Basically TOO similar to the 18650.
It's just dealers/mfg's trying to make another segment of a small market to have "some" people buy a few more battery's.

18650 cover MOST of the hand held electrical output market.
SOME (A LOT) find them a bit skinny in the hand to hold. whereas the 26650 fit much more comfortably.

The 21000 ser are NO thicker. to hold. with only a slight capacity advantage.
Why. Really.... Bother?.

Just joined to check a for sale ad, this caught my eye though....
If I run a 3500mah 18650 in my light, but decide to remove the adaptor and run a 5000mah 21700.... that 1500mah is only a slight increase in capacity??

JohnnyMac · « **Reply #5 on:** July 27, 2020, 02:37:12 AM »

That 1500 mAh is around 40% increase over the 3500mAh. 35-40% more runtime and little difference in size? Sounds like a no brainer to me. All your negatives about it honestly seem like positives to me, especially with 3000-4000 lumen edc lights where the extra amperage is needed. 3500mAh 18650 can only supply 10A at best. A 21700 will easily sustain 20A. Just my take on it.

Shift from 18650 to 21700