Of course, if you mean that your battery health has dropped from 86 to 80 in a short time, I will give the following suggestions.
1 Controlling the battery in the range of 20%-80% is beneficial to the health of the battery. 65% to 75% is the most durable and electricity-resistant stage of the battery, followed by 45% to 75% and so on. Try to keep the lithium battery between 20% and 80%.
2. The battery is very sensitive to temperature. Apple's official ideal temperature is between 0 and 35 degrees.
3. Fast charging while playing games will inevitably accelerate battery loss.