Various studies about a whole bunch of different batteries were done across the world, but what could we keep as a pro tip for our Li-ion every day batteries ?
Keep cool …
Firstly, keep your battery cool. That means you shouldn’t do big tasks on your smartphone or laptop while it’s charging. As the graphic show, you should stay between 20-40°C.
…and battery half-full
Secondly, try to stay around 50% of maximum charge. In other terms, the less you do complete cycles the more cycles you could have ! Complete cycle is charging from 0% to 100%. For example, using only 50% of your battery every day (from 75% to 25%) and charging every day (doing an half cycle), is better than charging your phone every 2 days (from 100% to, saying, 5%). Your battery will keep its capacity longer, and thus, achieve more « complete cycles ». As this graph shows, the best practice is to stay between 75-65% but it uses only 10% of the battery. So, try to find the best compromise that suits to your usage. I personally try to follow the light blue line (75-25%). Notice that going lower is worst than going higher.
SoC : State of Charge
DST: Dynamic Stress Test
This could be explained by the voltage needed to charge your battery. Going higher than 80% (red zone) needs higher voltage and damage your battery. Going lower than 20% is bad too, but current or voltage are not involved, the damage is done by parasite reactions.
Long story short ➡ graphically :