Why does my phone battery drain so fast?

Start with what Settings says

A phone battery that suddenly drains fast has one of three causes: something is using more power than usual, the battery has worn out, or the phone is too hot or too cold. You can tell which in a few minutes. On an iPhone, go to Settings > Battery to see the proportion of the battery used by each app.^[2] Android phones show a similar list under their battery settings, though the menu names differ by maker.

If one app dominates the list, that app is your answer. Close it, update it, or restrict what it does in the background. If nothing stands out and the whole phone just empties quickly, look at the battery itself.

Apps working when you are not using them

Apple's battery guide names the usual culprits. Background Activity means the battery was used by the app while it was in the background, and you can turn off the feature that allows apps to refresh in the background.^[2] Location use is another: you can optimize your battery life by turning off Location Services for the app.^[2] An app that wakes the screen all day costs power too. If an app frequently wakes your display with notifications, you can turn off push notifications for the app.^[2]

Weak signal and a bright screen

A phone in a poor coverage area works harder. Apple says "No Cell Coverage" or "Low Signal" in the battery list means you are in a poor cell coverage area and your device is searching for a better signal.^[2] That is common in valleys and on rural Virginia roads. Airplane mode stops the searching if you do not need calls.

Screen brightness is the other big one. Dim the screen or turn on Auto-Brightness to extend battery life.^[2] And a Wi-Fi connection uses less power than a cellular network,^[2] so stay on Wi-Fi at home and work.

The battery has aged

Every phone battery wears out. 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.^[1] Batteries of iPhone 14 models and earlier are designed to retain 80 percent of their original capacity at 500 complete charge cycles under ideal conditions.^[1] Batteries of iPhone 15 models are designed to retain 80 percent of their original capacity at 1000 complete charge cycles under ideal conditions.^[1] A phone that is two or three years old and charged daily is often at or past that point.

On an iPhone, Settings > Battery > Battery Health shows maximum capacity. If it is near or below 80 percent and the phone dies in a few hours, a new battery will help more than any setting. Apple says it will replace the battery for no extra charge if the capacity drops below 80%,^[3] under its AppleCare terms. For what it costs without that coverage, see how much a phone battery replacement costs in Virginia.

An old battery also shuts the phone down early. You're more likely to experience unexpected shutdowns when your battery has a low state of charge, a higher chemical age, or when you're in colder temperatures.^[1] A phone that jumps from 30 percent to off on a cold morning is showing its battery's age.

Heat and cold

Heat does lasting damage; cold does not. Apple says it is especially important to avoid exposing your device to ambient temperatures higher than 95° F (35° C), which can permanently damage battery capacity.^[2] That includes a dashboard in July. When using your device in a very cold environment, you may notice a decrease in battery life, but this condition is temporary.^[2]

A thick case can add to the problem. Charging your device when it's inside certain styles of cases may generate excess heat, which can affect battery capacity.^[2]

Quick checks to run today

Work through the steps above in this order and you will usually find the cause: the battery list first, then background refresh and location, then brightness, then updates and a restart, then battery health. If the phone is near 80 percent capacity or lower and still dies fast, get a quote for a new battery.

Stop and call a pro if

• The phone is hot with nothing running. Stop using lithium-ion batteries if you notice an odor, change in color, too much heat, change in shape, leaking or odd noises.^[4]
• The case is bulging or the screen is lifting. That is a change in shape; power the phone off and have a repair business look at it.
• A recent battery replacement still drains fast. The part or the install may be at fault, so go back to the shop with the receipt.
• The phone reports a battery it cannot verify. Apple says the battery health information on that screen might not be accurate, so have your battery checked.^[1]

Do not pry open a phone to swap the battery yourself unless you know the model well, and do not put an old battery in the trash; take it to a battery recycling drop-off.

Getting help in Virginia

Once the cause is clear, how to make a phone battery last longer covers the habits that slow wear, and the phone and tablet repair answers cover related problems. To compare local businesses, see phone battery repair on Loclis.

When you are ready, describe the problem once and local repair businesses quote it.