Battery health

If you're actually using it on battery power regularly, that's typical.

On a power bank is no better or worse than a power adapter as long as it's well designed.

Hi there Dorrrrrsssssaaaaa,

Thanks for joining us in Apple Support Communities! We understand after the battery health on your iPhone has decreased since purchasing it seven months ago. We're glad you're here, and we can provide some guidance.

To start, if you don't see any messages in Settings > Battery > Battery Health indicating the battery needs service, it should still be in good health. Regarding your concern about the battery health decreasing, we can clarify how Maximum Capacity percentage works in relation to battery usage on your iPhone.

"All rechargeable batteries are consumable components that become less effective as they chemically age. As lithium-ion batteries chemically age, the amount of charge they can hold diminishes, resulting in shorter amounts of time before a device needs to be recharged. This can be referred to as the battery’s maximum capacity—the measure of battery capacity relative to when it was new. In addition, a battery’s ability to deliver maximum instantaneous performance, or “peak power,” may decrease." Learn more here:

iPhone Battery and Performance

We hope this information is helpful. Don’t hesitate to let us know if you have any more questions.

Cheers.

Dorrrrrsssssaaaaa,

You're certainly welcome! Thanks for following up with us. The rate at which the maximum capacity decreases can vary dependent upon usage. 93% battery health indicates your iPhone battery is in excellent condition.

Let us know if you have any more questions!

Take care.