Test/Review of Efest IMR18500 1000mAh (Purple) 2016

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HKJ
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Test/Review of Efest IMR18500 1000mAh (Purple) 2016

Efest IMR18500 1000mAh (Purple) 2016
DSC_3280
Official specifications:


  • Model: 18500 High Drain
  • 15A Discharge
  • Capacity: 1000mah
  • Material: Li-Mn
  • Flat Top
  • Size:18.39(D)*49.79(L)mm

Efest%20IMR18500%201000mAh%20(Purple)%202016-info
These batteries are rated for high current and low capacity, but something is wrong. They have fairly high capacity and cannot deliver high current.
DSC_3279
DSC_3281 DSC_3282
DSC_3283
DSC_3284
DSC_3285
Efest%20IMR18500%201000mAh%20(Purple)%202016-Capacity
The discharge curve looks good, tracking is just about perfect and the cell has nearly double the rated capacity. The cells can handle 7A, but neither 10A or 15A
Efest%20IMR18500%201000mAh%20(Purple)%202016-Temp-7.0
At 7A the cell heat up, but nothing serious.
Efest%20IMR18500%201000mAh%20(Purple)%202016-Temp-10.0
At 10A the cell do not have time to heat.
Efest%20IMR18500%201000mAh%20(Purple)%202016-CapacityTimeHours
Efest%20IMR18500%201000mAh%20(Purple)%202016-CapacityTime
Efest%20IMR18500%201000mAh%20(Purple)%202016-Energy
Efest%20IMR18500%201000mAh%20(Purple)%202016-PowerLoadTime
Efest%20IMR18500%201000mAh%20(Purple)%202016-TripCurrent
Efest%20IMR18500%201000mAh%20(Purple)%202016-Charge
Conclusion
The batteries looks good for high capacity 18500 cells, but they are not high current cells.
Efest must have made a mistake when wrapping these cells.
Notes and links
The batteries was supplied by Efest for review.
As an extra test I did a 1A cycle on my calibrated SkyRC MC3000 and it showed 1906mAh.
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

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

HarleyQuin
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.

This is Efest how we know them.
For once the other way round.
Thanks for testing, HKJ.

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MG
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Good to know. Thanks for the test!

Barkuti
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Cheers Party

P.S.: any chance to get some hint about who is the real manufacturer of those cells?

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

Viruses DON'T cause diseases, they rather are a consequence of them. Read the book “Béchamp or Pasteur” by Ethel Hume for more information.

HKJ
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Barkuti wrote:
P.S.: any chance to get some hint about who is the real manufacturer of those cells?

I do not know it, but with the very good performance I would expect it is from one of the big manufacturers. I.e. you get a top quality cell, but not the type you expected.
It is probably only a limited number of cells that got the wrong wrapper, but if you get some of these cells it would be a good idea to test capacity. If it has high capacity, it is not a high current cell!

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Barkuti
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I'd better test the battery's ESR, no laboratory equipment here but, if you know what you're doing, even with basic equipment one can achieve wonders.

I have recently ordered one of these 5-digit digital voltmeters; should serve me nice enough to make sort of accurate battery IR estimations.

 

Cheers Party

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

Viruses DON'T cause diseases, they rather are a consequence of them. Read the book “Béchamp or Pasteur” by Ethel Hume for more information.

Calmaja
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HKJ wrote:

I do not know it, but with the very good performance I would expect it is from one of the big manufacturers. I.e. you get a top quality cell, but not the type you expected.
It is probably only a limited number of cells that got the wrong wrapper, but if you get some of these cells it would be a good idea to test capacity. If it has high capacity, it is not a high current cell!

May be wrong calculation when typing the spec, instead of typing capacity times 2, they do it on discharge current. More likely capacity times 2, discharge divide by 2 Big Smile
Kind of reverse of their previous version which have higher discharge current, lower capacity.
Other than difference between two cells, still looks very good 18500 though.

HarleyQuin
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Barkuti wrote:
any chance to get some hint about who is the real manufacturer of those cells?
There is only one cell on the market with this capacity in the 18500 format, that’s the Panasonic NCR18500. That is supposedly a LiNiCoAl cell and the 18500 equivalent to the NCR18650B.

Use HKJs comparator and compare it with the Enerpower 18500 2000mAh, which is known to have the NCR18500 inside. The graph at 0.2A discharge rate is identical. The Enerpower has added protection circuit, so at higher current the curve is lower than the Efest here.

Anyway, I’d never ever buy this Efest. You never know when they will change the cell used in this wrapper and you might get a true but crappy 1000mAh. If I want the 2000mAh, I buy the original Panasonic from a reliable source.

More on 18500s: Runner up is the Sanyo 1700 mAh (LiCo chemistry), then come some worse 1500’s, and then the high drain ones (LiMn, perhaps LiNiMnCo by now) in the 1100-1200mAh range.

Oshpark Boards:
HQ ProgKey: Universal Driver Programming Key . Boost: HQ 15mm/17mm programmable boost driver with ATtiny13A
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Barkuti
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HarleyQuin wrote:

Anyway, I'd never ever buy this Efest. *You never know when they will change the cell used in this wrapper* and you might get a true but crappy 1000mAh. If I want the 2000mAh, I buy the original Panasonic from a reliable source.

Agree. In my honest opinion, these rewrappers which on purpose conceal the true manufacturer's ID numbers on the batteries are shotting themselves in their feet, and potentially harming their customers. It's plain lame. Facepalm

 

This, for example, is something I can tolerate, no hidden crap here. Shenzen BAK seems to be their manufacturer, hope we can enjoy some kind of test soon (user bella-headlight recently purchased a couple of Liitokala 26650-50A 5000mAh li-ions, same Shenzen BAK cells, we'll see). 

 

Cheers Party

 

Please avoid fully quoting lenghty posts, namely with nested quotes. Trim quotes down to the essential. Helps with neatness and legibility. Thanks.

The human mind, and its programming, is at the forefront of a particular battle of The Light vs evil dark forces. Nearly every human being on this beautiful planet “Earth” has some sort of negative mind programming in its mind. And you better take care of your mind programming, or someone else will in this wicked world.

Viruses DON'T cause diseases, they rather are a consequence of them. Read the book “Béchamp or Pasteur” by Ethel Hume for more information.