Greg,
I copied the info below from a previous post I made. While I can’t attest to personally garnering results for undercharging Lithium cells as I don’t go there and never realized the need to perform said tests, as I allude to OEM cell manufacturers don’t recommend same. To that end I have consumed lots of data and information that supports my assertion that undercharging is not a GOOD thing…
Its appears to be universally acknowledged by OEM cell manufacturers that the STANARD Li-Ion charge interval is approximately 3hrs, depending on the SOS (state of charge)…
I’m not aware of any OEM cell manufactures that have published charge rates below 0.5C.
Diminishing returns can be expected of long/slow low current charge intervals with CC-CV algorithms. In fact its my belief that its a recipe for overcharge. In laymen’s terms the reasoning is rather simplistic; whereas lab tests have revealed charging at less than 0.5C takes many hours longer than the OEM recommendations of 3.0hrs and can result in the battery already being fully charged @ 4.1V. Negating the need for the constant-voltage phase to 4.2V and or the detrimental voltage/heat stress associated with same.
Soft overcharge encourages the production of metallic lithium particles and the associated safety compromises thereof, dendrites and or cell oxidation at the least.
Michael
