Check your battery health in Settings on any iPhone
Open Settings, then tap Battery, then Battery Health & Charging. You will see two numbers: your current maximum capacity as a percentage, and the condition status below it. Maximum capacity tells you how much charge your battery holds now compared to when it was new. A battery at 80% capacity holds 80% of the original charge.
The condition status shows one of four messages: Normal (battery is working as expected), Degraded (capacity has dropped but the battery still works), Service Recommended (Apple suggests you have it checked), or Service Battery (the battery needs replacement soon). These statuses are automatic — Apple's software monitors your battery and updates the status as it ages.
This screen also shows charging patterns. If you see "Charging Optimisation" enabled, your iPhone is learning when you charge it and slowing the charge speed to extend battery lifespan. You can turn this off if you prefer full speed charging, though it will wear the battery faster.
Key Takeaways
- Maximum capacity percentage shows how much charge your battery holds compared to new, and you find it in Settings > Battery > Battery Health & Charging.
- A battery at 80% capacity or above is considered normal, though performance may feel slightly slower as capacity drops.
- The condition status (Normal, Degraded, Service Recommended, or Service Battery) tells you whether Apple thinks the battery needs attention.
- Charging Optimisation slows your charge speed to protect battery lifespan, and you can disable it if you need faster charging.
What the capacity percentage actually means for daily use
Maximum capacity is not the same as current charge. If your battery shows 85% maximum capacity and you charge it fully, you get 85% of a new battery's full charge — not 85% of your screen time. So a phone that once lasted 10 hours on a full charge might last 8.5 hours at 85% capacity, assuming your usage stays the same.
Most people do not notice a difference until capacity drops below 80%. Between 80% and 70%, the phone still feels normal to most users. Below 70%, you may notice the phone shuts down unexpectedly under heavy load, even though the battery percentage says 20% or 30% remaining. This happens because the battery cannot deliver power fast enough when the phone demands it.
Capacity naturally drops over time. A typical iPhone battery reaches 80% capacity after about 500 full charge cycles — roughly one to two years of normal use. After two years, most batteries are between 75% and 85%. This is normal wear, not a defect.
When to replace your battery instead of the phone
If your capacity is below 80% and you want your phone to feel faster, battery replacement is usually cheaper than buying a new phone. Apple charges between $69 and $99 for an out-of-warranty battery replacement, depending on your model. If your phone is still under warranty or you have AppleCare+, the replacement may be free.
You can replace the battery at an Apple Store, an Apple Authorized Service Provider, or through Apple's mail-in repair service. The mail-in option takes about a week total. In-store replacement usually takes a few hours. Third-party repair shops often charge less but may use non-Apple batteries, which can affect performance and future warranty coverage.
If your condition status shows "Service Battery", Apple recommends replacement soon — the battery is degrading faster than normal and may fail without warning. If it shows "Service Recommended", you have time to plan, but replacement within the next few months is sensible.
Factors that degrade battery capacity faster
Heat is the biggest culprit. Leaving your phone in a hot car, using it while charging, or running heavy apps in direct sunlight all speed up capacity loss. Cold also damages batteries, though the effect is temporary — a cold battery will recover when it warms up. Repeated full discharges (draining to 0%) wear the battery faster than partial discharges.
Charging habits matter too. Keeping your phone plugged in after it reaches 100% does not damage the battery if Charging Optimisation is on, because the phone stops charging and just trickles power to stay at 100%. If you disable Charging Optimisation and leave the phone plugged in overnight, the battery stays at 100% for hours, which causes gradual wear. Charging to 80% and stopping there extends battery life, but most people find this impractical.
Heavy use — gaming, video recording, or navigation for hours — generates heat and drains the battery deeply, both of which speed degradation. Light use extends battery life. A phone used mainly for messaging and email will have higher capacity after two years than one used for gaming and video.
Why your battery health might show as degraded sooner than expected
If your phone is less than a year old and capacity is already below 85%, something is wrong. Defective batteries degrade much faster than normal. Contact Apple or your carrier to report it — you may be able to get a free replacement under warranty.
Sometimes the battery health reading itself is inaccurate. If you see a sudden drop in capacity (from 90% to 70% in a week), restart your phone. The battery monitoring system occasionally glitches and reports a lower number than the actual capacity. After a restart, the reading usually corrects itself.
If capacity stays low after a restart and your phone is under warranty, Apple will run a diagnostic test to confirm whether the battery is actually degraded or the reading is wrong. You do not need to pay for this test.
How to slow battery degradation going forward
Keep your phone between 50°F and 95°F (10°C to 35°C) when possible. Avoid leaving it in cars, direct sunlight, or near heat sources. If your phone gets hot during use, close apps and let it cool before charging.
Enable Charging Optimisation in Settings > Battery > Battery Health & Charging. This feature learns your charging schedule and slows the charge speed during the hours you are not using the phone, which significantly extends battery lifespan over years.
Avoid letting the battery drain to 0% regularly. If you use your phone until it shuts down, charge it as soon as possible. Partial charges throughout the day are gentler on the battery than one deep discharge followed by a full charge.
If you do not use your phone for weeks, store it with about 50% charge, not fully charged or fully drained. This minimises chemical stress on the battery during storage.
Frequently Asked Questions
What is a normal battery capacity after one year?
Most iPhones reach 85% to 95% capacity after one year of normal use. Anything above 80% is considered normal wear. If your phone is one year old and capacity is below 80%, contact Apple — the battery may be defective.
Does low battery mode damage the battery?
No. Low Battery Mode slows your phone's performance to use less power, which actually reduces the strain on the battery. You can use it anytime without harming battery health.
Can I replace the battery myself?
iPhones are difficult to open safely without damaging the screen or other components. Self-replacement voids your warranty and risks breaking the phone. Apple's mail-in repair or an Authorized Service Provider is safer and not much more expensive.
Will my phone get slower as the battery degrades?
Not directly from degradation alone. However, if capacity drops very low (below 50%), Apple throttles the processor to prevent unexpected shutdowns, which makes the phone feel slower. This throttling stops once you replace the battery.
Is it worth replacing the battery if capacity is at 75%?
That depends on how long you plan to keep the phone. If you upgrade every two years, 75% capacity is fine — you will not notice much difference. If you keep phones for four years or more, replacement at 75% gives you another two years of good performance before the next degradation cycle.