MEDIUM FIX
Battery degraded below 75% capacity
Lithium-ion battery chemistry degradation from charge cycles
The original 5500 mAh battery typically degrades to around 75% capacity after 800-1000 charge cycles, which usually happens in years 2-3 of regular use. Replacement is straightforward but requires opening the device. Original Xiaomi replacement batteries are available from Mobilesentrix at around $14 USD wholesale.