Test/review of Shockli 21700 3800mAh (Green) 2018

Shockli 21700 3800mAh (Green) 2018







Official specifications:

  • Model : Shockli IMR 21700 3800mAh 40A

  • Capacity: 3800mAh

  • Voltage: 3.7V

  • Discharge Cut-off voltage: 2.75V

  • Standard Charge: 0.3 A~3A (Recommend 0.5 A~1.5A) /4.2V±0.05V

  • Maximum charge current: 3A

  • Continuous Discharge Current: 30A

  • MAX Discharge Current: 40A

  • Impedance: 15 m?

  • Positive: Flat Top

  • Size(mm): 21.5±0.2mm(Diameter) x 70.5mm±0.2mm(Length)

  • Weight(g): 71±2g

  • Cycle Life: 500times to 70%



The new size battery in a high capacity, but also rated for high current.










The discharge curves matches very well and the cell has nearly constant capacity independent of load, but it gets rather warm at 30A.





















Conclusion

The cell is a very good high current battery with good capacity and has better performance than any 18650 cell and up to 20A it is also one of the good batteries in the new sizes (20700/21700)



Notes and links

The battery was supplied by shockli.com for review.

How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries
Compare to 18650 and other batteries

Thanks for the review HKJ. :+1:

HKJ,

Thanks for testing these.

Looks like this new size is really starting to take off.

Loved the (under)statement: “the cell has nearly constant capacity independent of load, but it gets rather warm at 30A”

I read the graphs and was thinking “Wow”, seemed almost totally unworried by the load put on it!

Cheers,
S-L :slight_smile:

Looking nice! I agree with Splott-Light

The specs are exaggerated, namely current handling. Looking at the temperature graphs, both cells went way above +50°C at 20A. Thus, 0K consistency, less than 20A continuous and ≈3700mAh, and I'm being magnanimous.

Is the Lii-40A review coming close?

Cheers :-)

Yes, current handling is exaggerated, but that do not prevent it from being a good high current cell.

Yes, I have one more battery in queue before it.

This seems like a nice combination of capacity and high-drain. Fits in between the Samsung 21700 30T and 48G.

thanks for the review ,another nice battery from Shockli.

These cells maybe are from the same OEM as the cell under the Lii-40A wrap. Had a couple Lii-40As weeks ago, bought them for a friend. Measured 3865 and 3898mAh in a Lii500's 0.5A discharge ratio NOR test, and their average internal resistance score was slightly below that of Samsung 30Q cells.

Cheers ^:)

Vapcell/Golisi/iJoy/Efest/Basen all have very similar batteries on paper to this one.

With Samsung/Sanyo on board with the 20/21700 size as well as the Vape industry we, as flashlight people, should officially declare 26650 dead. I see no purpose making future lights with that cell. It’s a “vape only” format w/ no real buy in from other industry.

3800 mah is nice, but weren’t the recent 26650 in the 5000 mah range? Regardless, because Tesla is going 21700 as will other car makers, I expect that’s going to see some huge increases in power and longevity in that form factor the next few years. Which may mean that 18650 eventually goes away?

Samsung 48G is already 4800mah @ 10A and we are in 21700 infancy.

Of course you will find a bit higher mah battery in 26650 size but that’s because it’s huge not because it’s superior construction or something. Give it time and im sure you will see some new technology that brings them much closer together since it has such big companies backing it.

No, 48G is just under 4600 mAh @ 10A. It’s 4700 mAh with minimal load.
Vapcell Purplue 5000 (probably rewrap of LG INR21700H30) is 4800 mAh with minimal load.

If I’m not wrong, comparing the poles of the Lii 40 and the positive pole of Shockli with the Basen 21700 4000mAh, I see that they look very much.
So theoretically they can be the same batteries.

Basen 21700 4000mAh is a battery made by Chinese Lishen which indicates that the battery is capable of 12 Amperes.

I measured the battery (Basen) , I saw that with 15A it had a temperature rise of 65 ° C.

However, it may have been a bit higher temperature because I’m not absolutely sure about the temperature sensor, because of a low friction

However, in general use of the battery with demand at ± 18 A with intermittent discharge, I did not see any worrying temperature.

So if the Lii 40 and the Shockli have the same element as Basen, then we are talking about Lishen batteries.
Until we see the large manufacturers’ batteries in the market, I think it’s a good solution.

First of all, thank HKJ for his hard work.
New Energy vehicles are currently a very popular Industry in China .Tesla states that 21700 can reduce costs in car makers ,So the Energy vehicles factory in china also want reduce cost ,they Require battery factory to produce 21700 cells .

More factories that will produce the 21700 battery in china,and new technology that brings more capacity and higher discharge current .
I didn’t see 21700 battery apply on the flashlight.but it had applyed for E-CIG .

First of all, the form factor 21700 was not created for lanterns, especially not for cigarettes (it is better not to smoke at all and advertising of cigarettes has long been banned). This kind of elements was primarily created to power the electric motors. Help me, please remind, where such engines can be used, besides electric cars and electric motorcycles? True, this same format can also be used for bicycles with an electric motor. These engines require a lot of energy, so quite a few elements are required. Now help me answer another very interesting question. Suppose you want to create a 14S3P or 14S4P battery. It means, that it is necessary to purchase 14x3 = 42 or 14x4 = 56 elements (a total of 42 pieces or 56 pieces). However, when people come to you for a choice, they encounter a misunderstanding in the form of such a condition:

“Pair (4 Pair - maximum per customer)” or “(4 pieces - a maximum on the buyer)”

https://aliexpress.com/item/21700-shockli-21700-3800-30A-40A-Eleaf-istick-Pico/32913425142.html?spm=a2g0s.13010208.99999999.262.13eb3c00i7tAcy

This is how to understand, eh?

I wonder how much these elements “Turmera 21700 3750mAh” inferior in discharge characteristics Shockli-3800?

Turmera 21700 3750mAh


Just look at the negative poles of the two cells you are comparing; the one that HKJ tests in this thread is a cell manufactured by YongdeLi (Chinese manufacturer) that has official specifications 3750mAh this rated capacity and 40 amps of continuous discharge (30 amps actually in the tests, otherwise you could boil the water with, lol ) and its negative pole is flat and without asperity or engraving, as for the cell “Turmera” that you present us, its specifications are false, why? Just look at the inscriptions on his blue wrap, we can read from the side under the label of authenticity, part of the inscription: “70SA”. We would read “LS LR2170SA” if this damn label does not interfere with the reading, which means that this cell is manufactured by Tianjin Lishen (Chinese manufacturer also) and its true specifications are 4000mAh and 12 amps of continuous discharge (but it can be mounted easily at 20 amps without overheating (<80 ° c), only the life of the cell will be reduced if we exceed the 12 amps continuous starting) and more negative pole of this cell has a circular engraving which serves to bottom venting or degassing if you want. To prove to you all that I advance in my remarks I put you technical links for these two cell models.

The cell used by HKJ in his test:
-Link to official specifications on YongdeLi’s official website:

http://www.ydlxny.com/index.php/work1/show/25.html

-Link to an example of rewrap from this cell (by Vapcell):

The cell used by Turmera that you presented to us:
-Link to product sheet (commercial) with official wrap and official specifications:

https://www.18650batterystore.com/21700-p/lishen-lr2170sa.htm

In addition the photos that you will see on the page of the last link (Lishen LR2170SA) proves to you by comparing the two wraps (that of your cell and the Lishen) are the same (same colors, same inscriptions and presence of the circular engraving of degassing on the negative pole), here I can not do better to prove my good faith, lol.

Good point HydrAxx. The Lishen LR2170SA cell was tested by HKJ under the LiitoKala Lii-40A wrap. It can be seen in the following graph that 15A continuous is already a bit too much for it, it is 3C rated after all:

( ಠ ͜ʖರೃ)

It may also be that the cell actually is the one tested here, rewrapped by Golisi too (S35), but the AliExpress seller is using incorrect cell photographs. Yongdeli cell as you said HydrAxx. Funny how these chinese companies like to overrate their products, 40A? :facepalm: I would use it at up to ≈20A continuous, no more.

By the way, a little birdie told me the following tri-lobe/leg top cells are likely to be manufactured by chinese OEM BAK:

https://www.aliexpress.com/item/40pcs-lot-Original-18650-3-7V-2600mAh-For-batteries-rechargeable-Battery-ICR18650-26F-safe-batteries-Industrial/32795814865.html

In this cylindrical cell basic product specifications list document (found here) I can discern it is model N18650CK, up to 2900mAh capacity and ≈35mΩ (got 35.4mΩ average in my measurements). They're 2C rated in the document, which is conservative. Pretty sure they can do 4C safely, I have 4 of them an AliExpress seller sent me instead of Samsung 25Rs (asked for half refund and got it, ended up paying €1.43/cell).

Hey! Look at the big pack you get for little money! 2 of them or more (80+ cells) does a nice e-bicycle battery already.

Cheers ^:)

HydrAxx & Barkuti, thank you for your very useful information. However, despite the presence on the market of good elements 18650 and ready-made cases for their installation in a battery for a bike (for example, e-bike battery case ), I select elements in the format 26650 or, as a last resort, 21700. For example, I encountered some unknown 26650, which also seemed interesting to me, but the question about them is still there without answers Test/review of Shockli 26650 4300mAh (Green) 2018 - #5 by volchyonok