I'm looking on NKON site at Samsung ICR18650-26x cells in order to build a second battery that is compatible for paralleling with my existing pack that uses ICR18650-26F cells.
They offer 3 variations:
ICR18650-26F @ €3.40
ICR18650-26H @ €2.55
ICR18650-26J @ €2.65
I went looking for differences that would explain the markup of the F cells. I downloaded the Samsung specification pdfs for all 3 and flicker compared them page by page and the differences I found are remarkably few.
The nominal voltage of the F variant is listed as 3.7V, whereas the other two are given as 3.63V.
Under the heading "Status of the cell as of ex-factory", the OCV voltage for 50% charge is given as 3.65V to 3.85V for the F & H variants and 3.55V to 3.75V for the J variant.
Under "External Short-circuit Test", the test calls for <50mOhm wire for F & H; but 60-100mOhm wire for the J.
Under "PTC Specification (in the Cell)" There are small differences:
(I believe that the PTC stands for "positive temperature coefficient"; a thermal protection device.)
I set out to try and understand why I should pay 30% more for the F variant, and other than the 0.07V higher nominal voltage, I'm not seeing anything to justify that extra cost.
Am I missing something? Or just being too anal.
Thanks Buk.
They offer 3 variations:
ICR18650-26F @ €3.40
ICR18650-26H @ €2.55
ICR18650-26J @ €2.65
I went looking for differences that would explain the markup of the F cells. I downloaded the Samsung specification pdfs for all 3 and flicker compared them page by page and the differences I found are remarkably few.
The nominal voltage of the F variant is listed as 3.7V, whereas the other two are given as 3.63V.
Under the heading "Status of the cell as of ex-factory", the OCV voltage for 50% charge is given as 3.65V to 3.85V for the F & H variants and 3.55V to 3.75V for the J variant.
Under "External Short-circuit Test", the test calls for <50mOhm wire for F & H; but 60-100mOhm wire for the J.
Under "PTC Specification (in the Cell)" There are small differences:
Code:
Hold Current Resistance PowerDissipation ResistanceAfterTrip
ICR18650-26F 2.7A 9~18mΩ Max. 2.5W Max. 33mΩ
ICR18650-26H 2.9A 7~16mΩ Max. 2.5W Max. 28mΩ
ICR18650-26J 2.9A 7~16mΩ Max. 2.5W Max. 28mΩ
(I believe that the PTC stands for "positive temperature coefficient"; a thermal protection device.)
I set out to try and understand why I should pay 30% more for the F variant, and other than the 0.07V higher nominal voltage, I'm not seeing anything to justify that extra cost.
Am I missing something? Or just being too anal.
Thanks Buk.