Test/review of Sanyo UR18650FB 2400mAh (Red)

[size=+3]Sanyo UR18650FB 2400mAh (Red)[/size]



Official specifications:

• Nominal capacity: 2400mAh
• Nominal voltage: 3.70V
• Charging: 2400mA to 4.2V
• Maximum discharge current: 4800mA

This is a old "high capacity" cell.











The discharge curves tracks nicely, but the cell cannot deliver more than about 2C, i.e. about 5A.





















[size=+3]Conclusion[/size]

This cell may have been a very good cell when it was made, but it is way behind a modern cell in both capacity and current.



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

Vapcell told me that I was missing some cells in my comparator and they would be happy to supply them.

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
Compare to 18650 and other batteries

What calculation did you perform to get 0.23 ohms IR? That seems too high.

2400 mAh must have been hot what, about 7-8 years ago?

Gauss163 said:

What calculation did you perform to get 0.23 ohms IR? That seems too high.

Click to expand...

No reply, so I will explain what I think is happening. The "How is the test done" link says that IR is calculated from the slope of the (first?) curve in the protection test, using the final 2A segment of the curve. But above this final 2A segment is far past the max current rating of the cell, i.e. it is between 12.6 - 14.6A, but the cell is rated at 4.8A max. If we calculate the slope at this max rating - say between 3A and 5A - then instead of 230 mOhms we get 110 mOhms - consistent with Sanyo's datasheet value for this class of cells.

There are no widely-used standards for calculating and comparing IR. But surely it is more useful to report values measured in normal usage ranges rather than in abnormal ranges where cell is extremely overloaded so the IR increases greatly (e.g. over 2x in the above test).