......I've seen that rating on a few cell specs on websites and sometimes it is in error (ie: they just copied the info from another cell chemistry)......
As with any type of cell, there are a lot of variables due to the actual components the cell is constructed of. While the chemistry of a cell may be capable of producing large amounts of current, cells can be limited by other factors, such as the means by which current is delivered to the + and - contacts of the cell. These components are not directly related to the chemistry itself.
The
LiFePO4 123 cell from
batteryspace.com for example, is limited to 1C. I've seen other RCR123 and CR2 LifePO4 cells, and I think some LiFePO4 14500's that were limited to a 1C charge/discharge rate, or less, as well.
As for the distributors being in error when writing up the cell info,
this 9 Volt LiFePO4, also from BatterySpace, is a good example. From the writeup it sounds as if this battery is capable of being charged at 500mA (2.8C) and discharged at a 5C (0.9A) rate. However, if you look at
the .pdf, it's really only capable of 0.5C charge and discharge rates (0.09A/0.09A).
As I said before, the C rates for smaller LiFePO4 cells seem to be lower, but do vary. Once you get up to the 18650 size, rates are generally higher than for LiCo Li-Ion cells, but can still vary from 1C to 30C, depending on the construction of the cells.
Dave
