Test/Review of Keeppower IMR18650 2500mAh (Black) 2014

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HKJ
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Test/Review of Keeppower IMR18650 2500mAh (Black) 2014

Keeppower IMR18650 2500mAh (Black) 2014

DSC_4887

Official specifications:

  • Min Capacity: 2400mAh
  • Typical Capacity: 2500mAh
  • Normal Voltage: 3.6V/3.7V
  • Cell: Made in Korea
  • Quality Lithium Ion rechargeable cell made in Japan
  • Maximum Capacity and Reliability
  • Maximum Constant Discharge Current: 20A
  • 4.2 volts max voltage and 3.6-3.7 volts nominal voltage
  • Button top: Yes
  • Dimension: (D)18.50mm*(H)66.50mm
  • Weight: Max. 49.0g


Keeppower%20IMR18650%202500mAh%20(Black)%202014-info

For once I did not use my 2.8 volt cutoff, but discharged down to 2 volt (This is the lower limit for these batteries).

DSC_4886


DSC_4888 DSC_4889

DSC_4890
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Keeppower%20IMR18650%202500mAh%20(Black)%202014-Capacity

The battery has no problem delivering 20A.

Keeppower%20IMR18650%202500mAh%20(Black)%202014-CapacityTimeHours

Keeppower%20IMR18650%202500mAh%20(Black)%202014-CapacityTime

Keeppower%20IMR18650%202500mAh%20(Black)%202014-Energy

Keeppower%20IMR18650%202500mAh%20(Black)%202014-PowerLoadTime

Keeppower%20IMR18650%202500mAh%20(Black)%202014-TripCurrent

Keeppower%20IMR18650%202500mAh%20(Black)%202014-Charge



Conclusion

The battery can be discharged down to 2 volt, but the voltage does compare favorable to other LiIon batteries with a higher end voltage. Using a cell from LG I will call this a very good high current battery.



Notes and links

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

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

Edited by: HKJ on 04/10/2014 - 11:03
lopedevega
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Thanks for the review.

Ejected Filament
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Recharge from 2v, safely? Did I read that right? They will all recharge from 2v, its just not recommended normally due to shunts or whatever. Why is this one different?

HKJ
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Ejected Filament wrote:
Recharge from 2v, safely? Did I read that right? They will all recharge from 2v, its just not recommended normally due to shunts or whatever. Why is this one different?

All LiIon manufacturers experiment with the exact chemical and physical construction of the cell. This cell  is obvious slightly different in composition, allowing a lower voltage.

I did search for data sheets to confirm the 2 volt, but did only find a rev 0 data sheet on google, that specified 2.5 volt. I hope Keeppower has more up to date information.

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

Hikelite
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HKJ wrote:

Ejected Filament wrote:
Recharge from 2v, safely? Did I read that right? They will all recharge from 2v, its just not recommended normally due to shunts or whatever. Why is this one different?

All LiIon manufacturers experiment with the exact chemical and physical construction of the cell. This cell  is obvious slightly different in composition, allowing a lower voltage.

I did search for data sheets to confirm the 2 volt, but did only find a rev 0 data sheet on google, that specified 2.5 volt. I hope Keeppower has more up to date information.

HKJ can you ask a confirmation from KP on 2.0 volt ? maybe it was a typing error as you know they have made typing errors in the past, some quite serious.

Ejected Filament
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Be good if it can go to 2v without causing issues. As always, thanks for the reviews HJK.

djozz
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thanks for the review HKJ!

RaceR86
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Impressive battery. Thanks for the review HKJ. Smile

Anyone know where to buy these cells?

BLF LED database – collaboration spreadsheet and latest news about where to buy LEDs
http://budgetlightforum.com/node/19342

Lothar
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Awesome review HKJ, thank you.

BTW, are these the same IMR cells as in the purple Efest 35A 2500mah's?

Current Collection:

BLF: BLF-GT90, BLF-GT70 (CW Sliced), BLF GTmini, BLF-LT1; 

BTU: Shocker (3 x SST-40 @ 8A)

Solarforce: L2P (XM-L2 U3 @ 4A), MPP-1 (XP-L HI @ 6A), MPP-3 (3 x XM-L2 U2 @ 12A), M6 (Nichia 319A @ 6A), M8 (XHP-50.2 @ 9A), 9x (9 x XM-L2 U2 @ 2A)

Coming Soon: Lumintop: BLF-GT4; 

HKJ
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Hikelite wrote:
HKJ can you ask a confirmation from KP on 2.0 volt ? maybe it was a typing error as you know they have made typing errors in the past, some quite serious.

I will ask.

Lothar wrote:
BTW, are these the same IMR cells as in the purple Efest 35A 2500mah's?

I do not know it, but some people say it is. I have also heard that the battery is only rated for 35A current for a couple of seconds.

I will be testing the Efest soon, it is next in line for my test station. It will be down to the usual 2.8 volt and up to 30A discharge current.

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

Lothar
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HKJ wrote:

I will be testing the Efest soon, it is next in line for my test station. It will be down to the usual 2.8 volt and up to 30A discharge current.

Awesome thanks, looking forward to that Big Smile

Current Collection:

BLF: BLF-GT90, BLF-GT70 (CW Sliced), BLF GTmini, BLF-LT1; 

BTU: Shocker (3 x SST-40 @ 8A)

Solarforce: L2P (XM-L2 U3 @ 4A), MPP-1 (XP-L HI @ 6A), MPP-3 (3 x XM-L2 U2 @ 12A), M6 (Nichia 319A @ 6A), M8 (XHP-50.2 @ 9A), 9x (9 x XM-L2 U2 @ 2A)

Coming Soon: Lumintop: BLF-GT4; 

Ledsmoke
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Awesome battery. Awsome test! Thank you Smile

~ Ledsmoke ~

Dutch humor:

[quote=djozz]

 I do not think that the BLF-community ben

HKJ
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I got answer from Keeppower.

The cell is rated to 2.0 volt "end voltage". This is specified for both 0.5A discharge and 20A discharge.

Maximum continuous discharge is also specified as 20A, i.e. if Efest is using this battery their specifications are way higher than the cell manufacturer says.

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

Hikelite
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Thanks HKJ.

Tom E
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Somehow I missed this review, Thanks HKJ!! Didnt' realize these KP's are LG cells.

Just got 2 pairs of the LG HE2 cells in yesterday from FT. They compare pretty much the same as the Efest 35A cells - exact or within 0.01A of each other in a light with the Nanjg FET based driver (direct drive). I was getting 5.69A on the LG's, and best I saw was 5.70A on an Efest 35A, Sam 20R, and Powerizer. In a Super Shocker, they did 6.08A - best I got on the Super Shocker was 6.20A with 2 Efest 35A's and one SONY VTC5. It's all so close, within any reasonable margin of variation of charging level, test setup, etc.

These are sooo close to Sam 20R's, with the 20R's dying quick after 30 secs, dunno, these cells seem to be a great alternative with a better discharge curve and longer runtime. Just use HKJ's comparator (http://lygte-info.dk/review/batteries2012/Common18650comparator.php), and compare the 20R to the KP IMR 2500 and look at the 5A discharge curve....

Bought mine here: https://www.fasttech.com/products/1659701. Really like'n these...

shadockan
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The site of KeepPower however, the new IMR 2500 must be Samsung SDI INR 18650 25R