It’s a matter of balancing convenience with battery longevity.
The best but unrealistic way:
Recharge once the battery drops 10%; deeper discharge degrades battery more.
Keep the battery as close to the middle range as possible. Extreme battery levels, which are levels closer to 0% and 100%, reduce battery capacity.
But that defeats the purpose of using a smartphone, which is CONVENIENCE. That said, what you can do instead are:
Recharge whenever convenient. Don’t let it fall below 20% (or higher) and avoid fully discharging the battery unless calibration is needed.
Unplug at battery level between 80% (or lower) and 100%. Don’t let your phone stay at 100% level for too long, i.e., plugging to charger after fully charged.
There’s no absolute rules to follow. Most suggest the 20 – 80 rule, which you can definitely follow. You can even do 45 – 75 or others.
As long as you understand what’s harmful to your battery, you can tailor your charging habit according to your needs and daily routine. Because while you can definitely improve battery life significantly, it’s pointless if it demands sacrificing your enjoyment and convenience, which is what your smartphone is supposed to bring you.
If you prefer charging to 100% for maximum runtime, check out the cable that auto disconnects the battery at full charge for you.
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