Test/review of Parkside INR18650E 2000mAh (Blue)

Batteries and Chargers Rechargeable Batteries
1

Parkside INR18650E 2000mAh (Blue)







Official specifications:

  • Capacity: 2000mAh

  • Nominal voltage: 3.7V

  • Type: LiIon

  • Voltage for 5: 20V





The batteries has been removed from a unused Parkside 2.0 PAP 20 A1 battery pack.



The marks from the spot welded strips are visible.






There is a small difference in capacity between the two cells.







The 30A discharge went wrong, on cell was terminated due to temperature, the other cell terminated itself, i.e. a fuse inside the cell disabled it.















Conclusion

The cells looks fairly good, they are obvious not for 30A, but 20A looks fine.



Notes and links

These batteries was supplied by a reader for review.

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
Graphical comparison to 18650 and other batteries
Table with all tested LiIon batteries
2

Thank you so much!
Those results are way better than I expected - seams like those battery packs are pretty decent for the money (4Ah Pack for 28€)

3

Looking through the comparator, it seems the closest “Major Brand” cell to this is the Samsung INR18650-20Q. It seems they are almost, but not quite, identical chemistry inside. The discharge curves at 5A, 10A, and 20A are almost identical. The 20Q doesn’t voltage sag as much at the beginning of the curve, but drops off a bit earlier at the end (lower capacity, even though they’re rated the same). The comparator doesn’t have a discharge curve for the 20Q at 30A, but the Parkside cell didn’t do well with that test.

4

Pentalobe/pentaleg tops, could these be Shenzhen BAK made?

Henrik, I think the calculated internal resistance figure in your charts needs a fix. “Cold” or barely warm cell DC internal resistance can be inferred from the discharge curve graphs. An easy algorithm could be “at ⅛ capacity figure value x-axis position read V(IREF) and V(IMAX) voltage values, then work out Rcell = (V(IREF) − V(IMAX)) / (IMAX − IREF)), whereas IMAX is the maximum current at which the cell succesfully completed discharge without issues or overheating and IREF could be the closest amperage value for which a measured discharge curve exists at ≈¼ of IMAX. In this particular case (values taken at 250mAh point):

Rcell = (3.83V − 3.4V) / (20A − 5A) = 430mV / 15A = ≈28.67mΩ.

5

It is automatic calculated by my test equipment during the “Protection test”, I do not really want to redo this.
Because I calculate it at a fairly high load with unprotected cells, some cells will give a rather high value.