Test/review of Vapcell Vapcell IFR32700 6500mAh G65 (Blue) 2020

Vapcell IFR32700 6500mAh G65 (Blue) 2020







Official specifications:

  • Model: IFR32700 G65 6500mah 30A

  • Size: 32.1*70.5mm

  • Nominal voltage: 3.20V

  • End-of-charge voltage: 3.65V

  • End-of-discharge Voltage: 2.0V

  • Typical Capacity: 6500mAh (0.2C discharge)

  • Min capacity: 6400mAh (0.2C discharge)

  • Weight: Max: 150g

  • Internal resistance: Max:8mOhm AC 1kHz

  • Standard Charge: 6000mA,CCCV 50mA cut-off

  • Quick Charge Current: 30000mA

  • Max Continuous Discharge Current: 30A

  • Max Pulse Discharge Current: 55A for 5 seconds



Fairly large (They are 5mm longer than 32650) LiFePO4 batteries that can deliver a lot of current.











The two batteries matches very well. Being LiFePO4 the discharge curve is very flat, until the battery is nearly empty. The batteries can also easily handle the 30A test current and without any drop in capacity.

















The charger curve for LiFePO4 is significantly different from LiIon.




Conclusion

Need a lot of current and stable voltage at around 3V, then these batteries are very good.



Notes and links

The batteries was supplied by Vapcell 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

What is the use case for these? High drain series battery packs?

LiFePO4 are not very good at capacity vs. size/weight, but can usually handles many more charge cycles than 4.2V LiIon.
This makes them very useful in application where you charge/discharge very frequently.
The voltage also fits nicely with 3.3V chips, i.e. a small LiFePO4 cell and a solar cell would work nicely for a low power application (I am also testing some small LiFePO4 cells).

Thanks HKJ!

I replaced a 6V lead acid battery with 2 LiFePo4 cells (2 in series) in a solar light. The original lead acid battery did last about one year (one hot summer probably killed the lead-acid battery).
The LiFePo4 cells are still working perfect for more than 18 months now (and these survived the hot summer of 2019).
Because of the voltage these cells are a very good replacement for 6V - 12V - 24V lead acid batteries, the working voltage of 2 LiFePo4 cells in series is about the same as a 6V lead-acid battery.
Just use a decent battery management system to protect the cells from deep discharging and overcharging and they will last a lot longer than lead acid batteries in applications with many charge/discharge cycles.
Because of the very high current that these cells can deliver it is best to use some kind of short circuit protection as well in a LiFePo4 battery pack.(most BMS have short circuit protection)

LiFePo4 is also much safer than lithium-ion, they don’t burn or explode as easy as lithium-ion.
The only drawback is a lower power density of LiFePo4 compared to lithium-ion cells.

another really cool review, thank you!

:wink: Thanks HKJ