iPhone battery health dropping fast: what is normal and what to do

Every iPhone battery loses a little capacity as it ages, and heat speeds that up. This guide shows how to read Maximum Capacity and cycle count, what Apple considers normal, and the habits that slow the drop.

A slow fall in Maximum Capacity is normal: Apple designs iPhone 14 and earlier batteries to keep 80% of their original capacity after 500 full cycles, and iPhone 15 and later after 1,000 cycles, in ideal conditions. Check Settings > Battery > Battery Health (or Battery Health & Charging on iPhone 11 to 14) and compare the figure with how long you have had the phone. If it is falling much faster, heat and charging habits are the usual suspects, and a battery below 80% is worth getting checked.

• 1. Open the Battery Health screen: Go to Settings > Battery. On iPhone 15 and later, tap Battery Health. On iPhone 11, 12, 13 and 14, tap Battery Health & Charging. This is where Apple shows the Maximum Capacity figure and any service message.
• 2. Read Maximum Capacity the right way: Maximum Capacity compares what the battery can hold now with what it held when new. A lower number simply means fewer hours between charges. Even a brand new phone can show slightly under 100% if it sat in a warehouse for a long time before you switched it on, so do not panic over a point or two.
• 3. Check the cycle count on iPhone 15 and later: On iPhone 15 models and later running iOS 17.4 or newer, the Battery Health screen also lists the cycle count, the manufacture date and the date of first use. One cycle means you have used the equivalent of a full battery, even if it was spread over several partial charges. These numbers help you judge whether the drop matches how hard the phone has been used.
• 4. Compare against Apple's design target: Apple says iPhone 14 and earlier batteries should hold about 80% after 500 full cycles, and iPhone 15 and later about 80% after 1,000 cycles, under ideal conditions. Daily use in a hot city is rarely ideal, so a slightly faster fall is not unusual. A phone that loses 10% or more in a few months with light use is worth a closer look.
• 5. Look at Peak Performance Capability: On iPhone 14 and earlier, read the line under Maximum Capacity. If it says the battery supports normal peak performance, all is well. If it mentions performance management after an unexpected shutdown, or says the battery health is significantly degraded, the battery is ageing faster and a replacement may be due. Apple notes that this message is not a safety issue.
• 6. Keep the phone out of the heat: Apple says temperatures above 35 °C can permanently reduce battery capacity, and charging in heat makes it worse. Do not leave the iPhone on a car dashboard, a sunny window sill or a hot bike seat in May and June. If it gets warm while charging, take it out of its case.
• 7. Turn on the charging protection settings: On iPhone 15 and later, go to Settings > Battery > Charging and consider setting a charge limit such as 80% or 90%. On iPhone 14 and earlier, keep Optimised Battery Charging switched on under Battery Health & Charging. Both reduce the time the battery spends sitting at full charge, which slows ageing.
• 8. Store a spare phone at half charge: If you are keeping an old iPhone in a drawer, charge it to around 50%, switch it off and keep it somewhere cool and dry. Apple suggests topping it back up to about 50% every six months. A phone stored completely empty can end up with a battery that will not hold charge.
• 9. Recheck after a few weeks: Give it a month of normal use with the habits above, then compare Maximum Capacity with the figure you noted. A steady, small fall is normal ageing. A sharp drop, a service message or sudden shutdowns mean it is time to get the battery tested.