What is the proper way to maximize long-term battery life? I’m referring to li-ion packs like the space cell. Is it best to recharge to 100% every time, or can I unplug before? Is it best to discharge the battery to almost empty before recharging to reduce charge cycles?
Charging to 80%, and discharging to 20% is best. Intact, that is what Tesla does to increase its battery lifespan.
That said, you should still charge it to 100% (and leave it on the charger even after its fully charged) every once and a while to keep the cells balanced.
All the balancing is done at the end of the charging, so by stopping at 80% every time, they will slowly get out of balance.
@Jedi I think a lot of this depends on whether you are charging\balancing your batteries yourself with an intelligent charger, or if your battery comes with an integrated BMS. If the former, @cmatson is spot-on. If the latter, the answer is “it depends.”
It practice, I charge my LIPOS to 100% (4.2V) and discharge to the lowest value before significant voltage sag (3.6V). I care more about extended riding time than preserving the battery eternally.