How to Make Your Phone Battery Last Longer, Today and for Years

Battery complaints come in two kinds. One is "my phone does not make it to bedtime," which is mostly about settings and apps. The other is "my phone used to last all day and now it does not," which is about battery aging. The fixes are different, and it helps to know which problem you have before you start changing settings at random.

First, check your battery health

Every lithium-ion battery slowly loses capacity as it ages. Your phone can tell you roughly how much.

• iPhone: Settings > Battery > Battery Health (on some models, Battery Health & Charging). It shows maximum capacity relative to new and whether performance management is active.
• Android: It depends on the manufacturer. Some phones show battery health or capacity under Settings > Battery or in a device-care or diagnostics section; others only show it in the maker's support app.

If health is good and the phone still dies early, the issue is usage. If health has dropped noticeably, a battery replacement may be the real fix (more on that below).

Find out what is using power

Both iPhone and Android show battery use by app in Settings > Battery. Look at the last 24 hours and the last several days.

• One app using a surprising share is often the culprit, especially social, video, navigation and games.
• High background activity for an app you barely open means it is working when you are not looking.
• Weak signal shows up as high cellular or system usage. Phones work much harder in poor coverage areas, basements and on crowded networks.

Settings that genuinely save battery

These have the biggest effect for the least sacrifice.

A few more worth knowing:

• Dark mode helps on phones with OLED screens, which includes most current flagship phones, because black pixels use little power.
• Always-on display and very high refresh rates use extra power. Turning them down helps if you are struggling to last the day.
• 5G can use more power in areas where coverage is patchy. Many phones manage this automatically; if yours does not, a setting that prefers LTE when 5G is not needed can help.
• Widgets and live wallpapers that update constantly add up.

You do not need to swipe away every app constantly. Both iOS and Android manage suspended apps well, and force-closing them can use more power when they relaunch from scratch.

Charging habits that slow battery aging

Lithium-ion batteries age faster with heat, with time spent at very high or very low charge, and with fast, hot charging. You do not need to obsess, but a few habits help over the years.

• Avoid heat. This is the big one. Do not leave the phone in a hot car or charge it under a pillow. If it gets hot while charging, take it out of a thick case.
• Turn on optimized charging. On iPhone, Optimized Battery Charging learns your routine and holds at a lower level overnight; some recent models also let you set a charge limit. Many Android phones offer Adaptive Charging or a setting to cap charging below full.
• Partial charges are fine. Topping up during the day does not hurt. There is no "memory effect" with lithium-ion.
• Do not routinely run it to zero. Deep discharges add wear.
• Use reputable chargers. Certified cables and chargers from the phone maker or established accessory brands handle power negotiation properly. Very cheap, uncertified chargers are a safety risk as well as a battery one.
• Storing a spare phone? Leave it around half charged, powered off, somewhere cool.

Myths you can ignore

• "Never charge overnight." Phones manage this safely; optimized charging handles the rest.
• "Fully drain it once a month to calibrate." Not needed on modern phones.
• "Closing apps saves battery." Usually not, as noted above.
• "Battery-saver apps help." Third-party battery apps cannot do more than the built-in settings and some are adware.

When it is time for a new battery

Signs that the battery, not your settings, is the problem:

• Battery health has dropped noticeably, or the phone shows a service warning.
• The phone shuts down unexpectedly at a percentage well above zero, especially in cold weather.
• The phone slows down under load (iPhones may manage performance on worn batteries to avoid shutdowns).
• The battery is swelling. A screen lifting away from the frame or a back panel bulging means stop using and charging the phone and get it to a repair shop promptly.

Your options:

• Manufacturer repair. Apple, Samsung, Google and other makers offer battery replacements through their stores, mail-in services or authorized repair partners. Prices are listed on their support sites and depend on the model and whether you have an extended warranty plan.
• Independent repair shops. Often quicker and cheaper. Ask whether they use genuine or high-quality parts and whether they offer a warranty on the work. Some phones show a notice when a non-genuine battery is installed.
• Do-it-yourself. Some manufacturers now sell genuine parts and repair guides, and several US states have passed right-to-repair laws that expand access to parts and manuals. Phone batteries are glued in and can be damaged if punctured, so DIY is only for the confident.

Before any repair, back up your phone. Our guide to backing up an iPhone or Android phone covers the steps.

Replace the battery or the phone?

A new battery is usually the better deal if the phone still gets security updates, performs well apart from battery life and has no other damage. A replacement can make an older phone feel new again for a fraction of the cost of upgrading. If the phone is near the end of its software support, the screen is cracked and the battery is worn, putting that money toward a new phone often makes more sense.

Quick checklist

1. Check battery health to see whether you have a usage problem or an aging problem.
2. Find power-hungry apps in Settings > Battery and limit their background activity.
3. Use auto-brightness, a shorter screen timeout and power-saving mode when needed.
4. Keep the phone cool and turn on optimized or adaptive charging.
5. Replace a worn or swelling battery before replacing a good phone.

With sensible settings and a bit of heat management, most phones stay comfortable to use for years.