philip
Well-known member
Being in Texas, heat will be the largest factor that shortens battery life. If you are okay with only charging to 80%, then keep doing it, it won't hurt anything.
The following paper shows that a lower charge voltage is better for longevity than a higher one (even if slight): https://www.researchgate.net/publication/303890624_Modeling_of_Lithium-Ion_Battery_Degradation_for_Cell_Life_Assessment). The data they present show that the batteries that were cycled from 100% SOC had accelerated capacity loss when the battery was new, but eventually the degradation follows the same rate as those batteries that terminated charge at 85% on Page 7. They speculate that this initial rapid degradation may have been caused by overcharging early in the tested batteries life, but they don't have data on that. When they adjust that early degradation out, it shows only a couple % difference in degradation between the 100% charged and 85% charged batteries that had the same DOD after many cycles.
According to the data presented, there will be a slight advantage to maintaining a lower SOC as far as battery lifetime. So slight, that you may get an extra month or two of life out of the battery over a five year battery lifetime.
I suspect for my use case (and probably yours), being in a warm climate, that charging to 80 vs 100 will make very little difference in the total lifetime of the battery.
The following paper shows that a lower charge voltage is better for longevity than a higher one (even if slight): https://www.researchgate.net/publication/303890624_Modeling_of_Lithium-Ion_Battery_Degradation_for_Cell_Life_Assessment). The data they present show that the batteries that were cycled from 100% SOC had accelerated capacity loss when the battery was new, but eventually the degradation follows the same rate as those batteries that terminated charge at 85% on Page 7. They speculate that this initial rapid degradation may have been caused by overcharging early in the tested batteries life, but they don't have data on that. When they adjust that early degradation out, it shows only a couple % difference in degradation between the 100% charged and 85% charged batteries that had the same DOD after many cycles.
According to the data presented, there will be a slight advantage to maintaining a lower SOC as far as battery lifetime. So slight, that you may get an extra month or two of life out of the battery over a five year battery lifetime.
I suspect for my use case (and probably yours), being in a warm climate, that charging to 80 vs 100 will make very little difference in the total lifetime of the battery.
I'm still under warranty until 2020, so the faster the better probably 
