Battery Health - Service

It means that your battery is starting to age and probably needs to be replaced soon. You'll most likely experience shorter battery lifespan with your phone.

Here's a quote from Apple:

"All rechargeable batteries are consumables and have a limited lifespan,

eventually needing to be serviced or recycled. There are various factors

that can affect the performance and lifespan of your device’s battery,

including number of charge cycles, chemical aging of your battery, and

exposure to extreme heat or cold."

You can learn more here: If you see 'Your iPhone battery may need to be serviced'

You can start a service request for a battery replacement here since most US Apple stores are still closed: Apple Repair