Test/Review of Coolook 14500 LiFePO4 700mAh (Black)

[size=+3]Coolook 14500 LiFePO4 700mAh (Black)[/size]



Official specifications:

• Battery Capacity (Mfg Rated): 700 mAh
• Battery Chemistry: LiFePO4
• Battery Feature: Rechargeable
• Battery Form Factor: AA/14500
• Battery Rated Voltage: 3.2 V
• Dimensions: Depth: 14 mm, Height: 54 mm, Width: 14 mm
• Product Weight 19 g

This battery is a 3.2 volt LiIon battery, not the usual 3.6/3.7 volt, this means that it may not work in lights designed for 3.6/3.7 volt batteries.
The LiFePO4 chemistry is generally safer than the 3.6/3.7 volt chemistry, but does also have less capacity.











The batteries has good tracking and the same capacity at any load up to 5A, this is very good performance.
The specification saying 700mA is way too high as is often the case on these batteries.





The battery can deliver 5A, but only for 6 minutes!









Remember to use a 3.6 volt charger, it is usual marked 3.0 or 3.2 volt.



[size=+3]Conclusion[/size]

This looks like a battery with fairly good performance and I will rate it acceptable.



[size=+3]Notes and links[/size]

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

Not long ago I picked up a 4-pack of Tenergy LiFePO4 AA cells out of curiosity. They're labeled 400 mAh, which apparently is more realistic than the ones you tested. I was surprised to find that they all measured right at 450 mAh at a 100 mA constant current discharge -- it's the first time I can recall ever measuring a cell at significantly more than its stated capacity. I believe the intended market for these is some newer solar yard lights where simple charging requirements are important. With energy density significantly lower than NiMH and cell voltage still below that of a power LED, it doesn't seem likely they'll find any use in flashlights.

c_c

Curious_character said:

With energy density significantly lower than NiMH and cell voltage still below that of a power LED, it doesn't seem likely they'll find any use in flashlights.

Click to expand...

LiFePO4 is not the best choice for single cell LED lights. But with two cells in series, it becomes a viable option. LiFePO4 is also a good option for incandescent lights. The flat discharge curve makes for a very well regulated output compared to the constantly decreasing voltage from other lithium chemistries, and can eliminate the need for regulation. Also, because it is a safe chemistry, running cells in series is a FAR less dicey affair. Energy density is lower than other lithium chemistries. But as the cell size increases, it compares more favorably.