iPhone 16 Pro 91% battery after 9 months?

On average, you can expect about a 1% drop in battery health for every 50 charge cycles. That's on "average." At 344 cycles, it would be expected your battery health to to be about 93% (+ or -). You're just 2% off of average, which is not something which should be concerning.

Read this about maximizing battery performance --> Batteries - Maximizing Performance - Apple

Best Practices:

1. Never let the battery full deplete and void letting the battery go below 20%.
2. DO - plug your phone in to charge when you go to bed at night, leaving it plugged in ALL night, EVERY night, with Optimized Battery Charging turned on.

Ciocio03 wrote:

hi thanks for reply

I DO let my phone plugged in all night but with the limit charge set to 80%, not optimized battery charging because I m not charging it to 100%

i tought i should concern because it was as slighty quick drop in percentange

As you found out, the charge limit does absolutely nothing to preserve battery capacity,

Change to optimised charging to 100% and start the day with equivalent of 91% of a new charge rather than 80% of 91% = 73%