Recommended best 21700 for my new purchase?

I bought 2 of these: https://www.banggood.com/Astrolux-F...endongling&cur_warehouse=CN&ID=62878306279756

One SST40 7000LM and one XHP50.2 11000LM.


This is what I'm thinking of using with these as I want to run it with 21700.
https://www.illumn.com/batteries-ch...1700-40t-4000mah-high-discharge-flat-top.html

Am I going right here, or is there a better option? Thank you!

There is no one best, competing goals are mutually exclusive.

40T is fantastic **power** density if you really need high C-rate discharge, say over 1C continuous and or over 3C bursts of say up to a minute.

But cells like 50E achieve higher **energy** density, and much better longevity for less stressful use cases.

john61ct said:

There is no one best, competing goals are mutually exclusive.

40T is fantastic **power** density if you really need high C-rate discharge, say over 1C continuous and or over 3C bursts of say up to a minute.

But cells like 50E achieve higher **energy** density, and much better longevity for less stressful use cases.

Click to expand...

Ok that helps. So, I would choose short term performance over longevity since I mainly will use this for navigating before daylight going duck hunting which is usually less than an hour at a time.

State your current load, figure your C-rate

Poor old ducks will be blind before you shoot them.
P

peter yetman said:

Poor old ducks will be blind before you shoot them.
P

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Lol, well it does help spot ducks on the way in, but mainly just to see where not to step.

I am looking for some 4800-5000mah 21700 in the UK for my new flashlight but everyone is out of stock, I am having problems even finding 18650 to 21700 adaptor tube, Might have to use O-rings.

A lot of 21700 seem to come from Tesla or other electric car battery`s, The Tesla ones are a pain to remove as they are glued in.

How NOT to extract the 21700 cells from a Tesla Model 3 battery - YouTube

ateupwithgolf said:

I bought 2 of these: https://www.banggood.com/Astrolux-F...endongling&cur_warehouse=CN&ID=62878306279756

One SST40 7000LM and one XHP50.2 11000LM.


This is what I'm thinking of using with these as I want to run it with 21700.
https://www.illumn.com/batteries-ch...1700-40t-4000mah-high-discharge-flat-top.html

Am I going right here, or is there a better option? Thank you!

Click to expand...

+

That's a good choice of battery.

I use the 5000mAh Samsung 21700s' & the runtime is just fantastic (geared for 10A, but still super)
https://www.illumn.com/21700-samsung-inr2170050e-5000mah-high-discharge-flat-top.html

50E is better for longevity than 40T

unless you **really** need that high power peak C-rate

The Samsung 50G is superior to the 50E

https://lygte-info.dk/review/batteries2012/Samsung INR21700-50G 5000mAh (Green) UK.html

And there is supposedly a Samsung 50S that is superior to the 50E and 50G. Still waiting to see tests on the Samsung 50S and the related Vapcell T50 cell:
https://budgetlightforum.com/node/75569

There is no one factor in "superior".

For those not needing the 3C continuous discharge rate - drained in 15min

then cycling longevity becomes the main value factor.

If you see pajda or docware or other respected testers publish longevity tests, please post a link back here.

Pricing from a trustworthy source for US market?

I feel like I'm in the Twilight Zone.
Has someone merged some threads?
I could swear that the original post was about duck hunting.
P

I typically look towards Molicel for most applications: P42 for high-drain and M50A otherwise.