Best 18650 cell: Keepower IMR18650 3200mah

[cwah]

Hello all,

I just found out this new cell from Keeppower:
http://keeppower.com.cn/products_detail.php?id=490

6C peak and 3C continuous for 3200mAH. Its capacity is almost as high as the latest NCR18650BE cell (3600mah) but it is a high discharge cell!!

See test:
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
http://www.candlepowerforums.com/vb/showthread.php?388203-Test-Review-of-Keeppower-IMR18650-3200mAh-(Black)-2014

 

[riba2233]

That IS panasonic 18650BE. I'm just testing panasonic one right now. It is 10A continuous, but that's as far as you should go. 20A maybe only for seconds.

 

[cwah]

What's the best price we can get for these cells?

 

[riba2233]

Probably depends on the quantity, but if you want just a few cells, then it's probably this:

http://eu.nkon.nl/rechargeable/18650-size/panasonic-ncr18650be-3-7v-2900mah.html

However, LG has a matching cell, same characteristics, and it's cheaper, and even has some more capacity on lower amps (it's the same on 10A):

http://eu.nkon.nl/rechargeable/18650-size/lg-inr18650mh1-3200mah-3c-battery.html

Their comparison:

http://www.dampfakkus.de/akkuvergleich.php?akku1=531&akku2=537&akku3=&akku4=&akku5=&akku6=&a=5

(efest is also re-wrapped panasonic BE)

And on 10A:

http://www.dampfakkus.de/highamps/537-at%2010A.png

Those cells will probably be cheaper if you buy larger quantities from some alibaba supplier, like evva or keeppower, or some other proven supplier.

But you are right, they are best cells if you want capacity AND performance. If you want to save some money and still get decent capacity and performance, you can get panasonic PF or samsung 29E. If you want extreme power, you should get samsung 25R or lg he2, and if you want the largest capacity, don't mind the lowish current and great price, you can get panasonic B or G.

 

[cwah]

I'm looking for highest capacity possible, but I pull between 1-2C constant.

Around 200cells. Where would be a good place to get them cheap?

 

[riba2233]

If you want to be brave, and you can wait, try contacting evva or keppower at alibaba for quote. If you want a sure deal, ask nkon.nl when are they getting lg mh1, or if they can give you discount for panasonic BE.

 

[\/ampa]

The 25R and HE2 and VTC5 have the lowest Internal Resistance this is not only good for "extreme power" but also for the efficency.
The useable cappacity is higher with lower IR.
Also the cycle life is better with lower C stress u put into cells.
If u run a 20A discharge rated cell vs a 10A discharge rated cell with 5A peak 3A constant the 20A rated will last longer.
The fastcharge ability from higher A discharge rated cells is also a bonus.

The Samsung 25R 2500mAh cells wight 45g while the Panasonic BD 3200mAh wight 48g and the LG MH1 3200mAh wight 49g.
If u weld 200 from these together it will wight 800g (~9%)more.

 

[riba2233]

But they have 21.8% less capacity... And he only needs 1 or 2 C.

 

[\/ampa]

Hmmm its better to compair with wh/kg.
Samsung 25R 2500mAh 200wh/kg nominal
Panasonic BD 3200mAh 235wh/kg nominal (17,5% more than 25R)

But the useable wh/kg is smaller becouse of different IR and depends on how much average and max. A u draw.
For example i guess they will both have same useable wh/kg if u draw 7A per cell.
Now u have also to consider the lesser cycle life with same useage.
And less max. charge current the BD have.

My opinion is its better to use for ebike (low power or not) 5,5kg of 25R than 5kg from these 10A 3,2Ah cells.
The 25R pack will last longer due to less stress also the option to charge @ 2C is sweet.
(or wait for the samsung 30R )