Shallow (partial) cycles are better for longevity (measured as permanent capacity loss over time). The effect is "better than linear;" see Table 2. https://ba

Shallow (partial) cycles are better for longevity (measured as permanent capacity loss over time). The effect is "better than linear;" see Table 2. https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries https://batteryuniversity.com/article/bu-808-how-to-prolong-... In general, li-ion has the properties you want: no "memory," deep discharge OK, partial charge OK. The one it lacks is "shelf life:" they don't like long-term storage at full charge. So they ship at 3.7 volts instead of the "full" 4.2V state. (This is the old wisdom of not keeping your laptop on a charger.) Lawn tools, for example, might have a smart charger that draws them down after a month without use. I imagine it's upsetting to need your flashlight, vehicle, etc., and it's only at 50-70% capacity.