Samsung 25R New Green Wrap 20A (25R5) 2500mAh 18650 Bench Test Results...a great 20A cell

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Mooch

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  • May 13, 2015
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    Tested at 10A-25A constant current. Cells were graciously donated for testing by Liion Wholesale.

    Dropbox - samsung 25r5 20a 2500mah 18650 wrap.jpeg

    Dropbox - samsung 25r5 20a 2500mah 18650 can.jpeg

    Dropbox - samsung 25r5 20a 2500mah 18650 top.jpeg

    Dropbox - samsung 25r5 20a 2500mah 18650 bottom.jpeg


    Disclaimer
    Testing cells at their limits is dangerous and should never, ever, be attempted by anyone who has not thoroughly studied the dangers involved and how to minimize them. My safety precautions are the ones I have selected to take and you should not assume they will protect you if you attempt to do any testing. Do the research and create your own testing methods and safety precautions.


    Bottom Line
    A true 20A continuous discharge current (CDR) cell that runs at moderate temperatures. This cell deserves its good reputation. This 25R5 green wrap cell is essentially identical to the earlier 25R2 blue wrap cell.


    Test Results
    Dropbox - samsung 25r5 20a 2500mah 18650 constant-current tests.bmp


    Comments
    • These are the new green wrap cells. The older blue wrap 25R's (25R2) were tested earlier: Samsung 25R Blue Wrap 20A 2500mAh Bench Test Results...a great 20A cell | E-Cigarette Forum
    • What's the difference between the blue wrap 25R2 and the newer green wrap 25R5? See this Battery Bro blog: Samsung 25R Upgrade - Green Samsung 25R5 vs. Blue 25R2 – 18650 Battery | BATTERY BRO The short version: Their performance is identical but we should get longer cycle life from the newer green wrap 25R5.
    • This cell has great capacity and moderate maximum temperature of 77°C at 20A.
    • Five additional cycles at 20A showed less than 1% loss in capacity and almost no voltage sag. A 10A discharge done after this showed a 1.2% loss in capacity. This is typical damage for a cell operating at its CDR.
    • While operating any cell at its rated maximum current causes damage to the cell, I would expect decent cycle life from the green wrap 25R5 at 20A.
    • A discharge at 25A brought the cell temperature to 91°C and dropped the voltage considerably. That's too hot and will significantly speed up the damage done to the cell. This is a 20A cell.
    • See my blog for more information on the testing procedures, equipment used, and links to all my test results.
     

    Froth

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    Chipotle.
    Samsung SDI states the performance between the 25R2(blue) and 25R5(green) should be identical, so I'm not surprised. You got all the info! Love these tests.

    Do you think that the change in chemistry in the 25R5 would improve cycle life with usage above 20A?, I'm assuming it would though I'm wondering by how much as I'm getting ~200 cycles with 0.12 daily use with the 25R2 before they're noticeably depleted.
     
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    Mooch

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  • May 13, 2015
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    Samsung SDI states the performance between the 25R2(blue) and 25R5(green) should be identical, so I'm not surprised. You got all the info! Love these tests.

    Do you think that the change in chemistry in the 25R5 would improve cycle life with usage above 20A?, I'm assuming it would though I'm wondering by how much as I'm getting ~200 cycles with 0.12 daily use with the 25R2 before they're noticeably depleted.

    I don't know, haven't done any cycle life tests. The electrolyte changes were supposed to result in better cycle life though. By how much? No idea. :)
     
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