Why is battery health decreasing quickly?

So my battery health was 92% 6 charges ago and now its 91%. Why is it going down fast

Your battery health is normal, as your battery settings indicate.

As you can see, Apple does not display tenths of a percent in the battery settings area. Apple always rounds down to the lowest number on the display. So, for example if the actual reading is 96.9%, that will be displayed as 96% on your phone.

It is very likely that your battery health was 92.0% and it declined very slightly over a few days to 91.9%. The battery only declined .1%.....but to you it appears as if it dropped 1% since 91.9% would be displayed as 91%.

There is no need to try to babysit the battery. It won't help and you will drive yourself crazy if you are worrying and checking the battery settings all the time.

There is really only one thing that you need to remember regarding the battery.......replace it when it is drops below 80%. That will be a long time from now.

It might be another discussion, but in my opinion Charge Limits.....if you are using them......are more of a gimmick than anything else. You will get better performance with less effort by setting the battery up for Optimized Battery Charging and connecting the phone to the power supply and leaving it connected all night....every night.

As the design target is 20% loss after 1000 cycles, yours would extrapolate to 20% in 750 cycles, so probably a little accelerated. However:

1. Loss of capacity not linear, it could stay at 87% for 6 months like one of mine
2. There is no warranty claim unless it gets to 80% inside the warranty or AppleCareplus cover petiod