Test/Review of K2 Energy 14500 LiFePO4 500mAh (White)

Batteries and Chargers Rechargeable Batteries
1

K2 Energy 14500 LiFePO4 500mAh (White)





Official specifications:

  • Nominal voltage: 3.2V

  • Nominal capacity: 500mAh

  • Nominal energy: 1.6Wh

  • Chemistry: Lithium Iron Phosphate




This is a LiFePO4 cell, this means lower charge voltage, less energy content and longer cell life.










This type of chemistry has a very flat discharge curve and the two cells match nicely.





The temperature raise is not very high, even at 10A.



At 15A there is no time for temperature raise, before my equipment cuts the discharge due to low voltage.















Conclusion

Depending on equipment the lower voltage may be an advantage or disadvantage, the capacity and energy is lower than normal LiIon. This chemistry is safer, because the self-ignition temperature is much higher.

For some applications this will be a good cell.


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
Comparison to other LiIon batteries
2

Interesting. I can clearly observe certain discharge traits for LiFePO4 batteries:

  • Resting voltage ≈3.4V.
  • ≈0.1V initial voltage “dip”, a very brief much steeper slope in the curve.
  • Quite flat discharge curve.
  • The higher the discharge rate, the earlier the end-of-charge internal resistance sag.

Should make decent power tool packs, if paralleled.

Any inexpensive source for these cells? Seen this K2 Energy 14500 LiFePO4 500mAh - 10A @eu.nkon.nl offer, but it's far from cheap. Any other high-discharge 14500 LiFePO4s?

Thanks.

Cheers ^:)