Originally Posted by sailabroad
Are those cycle figures(3-5K @ 50% DOD) just marketing
Thanks - and sorry for the Hijack.
Few points to make in response to your observations:
1. My measurement was conservative, I stated "usable" capacity, not "full" capacity. Full capacity would likely be around 90% of original. I never take my cells to 100% DOD, even for measurements.
2. Marketing claims are at ideal temp 25C and at 1C or less discharge rate. Higher temps and high discharge rates effect the lifecycle. My cells were used in EV where 3C rate is not uncommon for accelerations. In fractional C rate application like housebank your cell lifecycle should be a lot higher. This is why there will be a huge market for batteries
coming from EVs and getting a 2nd life in an energy storage
applications, which is precisely what happened to my cells.
3. Prolonged exposure to ambient temps above 40C-50C will certainly shorten lifecycle of cells. This is why many Nissan
Leaf owners in Arizona are not happy. This probably contributed to a few % points in my case as I drive around Tampa FL, but I never leave my car to bake in the sun.
Overall, these cells are excellent for housebanks, will provide years of service
at a fraction of the cost of new cells.