Where to find battery health information on Android

Android does not show battery health in one obvious place the way iPhones do. Instead, you need to dig into settings or use a hidden diagnostic menu. The most direct route is the Battery and device care section in Settings, which appears on Samsung phones and some others — it shows battery percentage and whether the battery is in normal condition. On other Android phones, you may find battery information under Settings > About phone > Battery information, though what appears there varies by manufacturer.

If your phone does not show battery health in Settings, you can access it through the hidden diagnostic menu. Dial *#*#4636#*#* on your phone's keypad (not in a contact or message). This opens the Testing menu. Tap Battery information and look for the line that says health. The values you will see are "Good," "Cold," "Dead," "Over voltage," "Unspecified failure," or "Unknown." Most phones show "Good" when the battery is functioning normally.

Some Android phones do not respond to the diagnostic code. If that happens, third-party apps like AccuBattery or Battery Health (available in the Google Play Store) can estimate battery wear by measuring charge cycles and capacity loss over time. These apps are not as precise as manufacturer data, but they give you a rough picture of whether your battery is degrading faster than normal.

Key Takeaways

  • Samsung and some other Android phones show battery health directly in Settings under Battery and device care, where you can see if the battery is in normal condition.
  • The hidden diagnostic menu (dial *#*#4636#*#*) reveals battery health status on most Android phones, showing whether the battery is Good, Cold, Dead, or experiencing another fault.
  • Third-party apps like AccuBattery estimate battery wear by tracking charge cycles, though they are less precise than built-in manufacturer tools.
  • A battery showing "Good" health can still lose capacity over time; if your phone drains much faster than it used to, the battery may be aging even if the status reads normal.

What the battery health status actually means

When you see "Good" in the battery health field, it means the battery is functioning within normal parameters — it is holding a charge and responding to the phone's power requests without error. This does not mean the battery is brand new or at full capacity. A battery can show "Good" health while still having lost 10 to 20 percent of its original capacity after a year or two of use.

"Cold" means the battery temperature is too low for safe operation, usually because you left the phone in a freezing environment. The phone will often shut down or refuse to charge until the battery warms up. "Dead" or "Over voltage" indicates a hardware fault — the battery itself is damaged and should be replaced. "Unspecified failure" or "Unknown" means the phone cannot read the battery's status, which sometimes happens after a software update or if the battery connector is loose.

The health status is separate from the charge percentage you see in your status bar. A battery at 50 percent charge can have "Good" health, and a battery at 100 percent can be degraded. Health tells you whether the battery is aging normally or failing; percentage tells you how much charge is left right now.

Signs your battery health is declining even if the status says Good

If your phone drains from 100 to 0 percent much faster than it did when new, or if it shuts down at 20 percent charge, your battery is losing capacity. This happens gradually over time and is normal wear — lithium batteries lose about 20 percent of their capacity after 500 full charge cycles (roughly two years of daily use). The battery health status may still read "Good" because the phone is not detecting a fault; it is just aging.

Another sign is if your phone feels hot during normal use or while charging. A degraded battery generates more heat as it works harder to deliver power. If the phone gets noticeably warm during light tasks like texting or browsing, the battery is likely wearing out. Swelling is a serious sign — if the back of your phone is bulging or the screen is lifting away from the frame, the battery is failing and should be replaced when ready, as a swollen battery can catch fire.

Check your screen-on time in Settings under Battery or Battery usage. If your phone used to run for eight hours on a full charge and now runs for four, the battery has lost significant capacity. Compare this to the battery's age — if it is less than two years old and losing capacity quickly, the battery may be defective and worth replacing under warranty.

How to test battery capacity yourself

The most reliable way to measure actual battery capacity is to fully charge your phone, then use it continuously until it dies, and note how long it lasted. Do this on a day when you can use the phone normally — not in airplane mode or with the screen off, which does not reflect real-world use. Compare the time to what you got when the phone was new. If you no longer have that baseline, assume a new phone of your model should last 12 to 18 hours on a full charge with moderate use.

AccuBattery and similar apps track charge cycles and estimate remaining capacity by measuring how much energy the battery holds after each charge. These estimates are not perfect, but they show you the trend — whether your battery is stable, slowly declining, or dropping fast. If the app shows your battery at 70 percent capacity after one year, that is normal aging. If it shows 50 percent capacity after six months, the battery is failing faster than it should.

Another test is to check the battery voltage using the diagnostic menu. Dial *#*#4636#*#*, tap Battery information, and look for the voltage line. A healthy battery typically shows between 4.0 and 4.3 volts when fully charged. If the voltage is consistently below 3.8 volts even after a full charge, the battery is degraded and losing the ability to hold a charge.

When to replace your Android battery

If the battery health status shows "Dead," "Over voltage," or "Unspecified failure," replacement is necessary — the battery is not functioning safely. If the phone is less than two years old and still under warranty, contact the manufacturer or your carrier about a free replacement. If the phone is out of warranty, a replacement battery and installation typically costs between $50 and $150 depending on the phone model.

If the health status reads "Good" but your phone dies at 20 percent charge, drains in half the time it used to, or gets hot during normal use, replacement is worth considering. You do not have to replace it when ready — the phone will still work — but the battery will continue to degrade. If you plan to keep the phone for another year or more, replacing the battery now is cheaper than buying a new phone later.

Some phones are easier to replace than others. Samsung phones, Google Pixels, and most mid-range Android phones can have the battery replaced by a technician at a carrier store, an authorized repair shop, or sometimes at home if you are comfortable opening the phone. Some newer phones have the battery glued in, which makes replacement harder and more expensive. Check your phone's repair manual or contact the manufacturer before deciding.

How to extend battery life while your battery ages

Slowing battery degradation starts with how you charge. Lithium batteries last longer if you keep them between 20 and 80 percent charge most of the time — charging to 100 percent and draining to 0 percent every day speeds up aging. If your phone has a Battery Saver or Adaptive Battery feature, turn it on. These features limit background activity and reduce power draw, which means fewer full charge cycles per week.

Reduce screen brightness and screen-on time when possible. The display uses more power than any other component, so lowering brightness by 20 percent can add hours to your battery life. Turn off location, Bluetooth, and Wi-Fi when you are not using them. Close apps running in the background — check Settings > Apps or Battery usage to see which apps are draining the most power, and close or uninstall the ones you do not need.

Keep your phone cool. Heat speeds up battery aging, so avoid leaving your phone in direct sunlight, in a hot car, or near a heat source. If your phone gets warm while charging, unplug it and let it cool down. Use a charger that matches your phone's specifications — a charger rated for higher voltage or amperage can damage the battery. Avoid wireless charging if your phone supports it, as it generates more heat than wired charging.

Frequently Asked Questions

What does it mean if my battery health is Unknown?

Unknown usually means the phone cannot read the battery's status, often because the battery connector is loose, the battery is not recognized, or there is a software glitch. Try restarting your phone. If it still shows Unknown, the battery may need to be reseated by a technician, or the battery itself may be failing and need replacement.

Can I improve my battery health once it starts declining?

No. Battery degradation is permanent — once a lithium battery loses capacity, you cannot get it back. You can only slow future degradation by charging between 20 and 80 percent, keeping the phone cool, and reducing power draw. If your battery has already lost significant capacity, replacement is the only way to restore full performance.

Is it safe to use my phone if the battery health is Cold or Over voltage?

Cold is temporary — warm up your phone and the battery will return to normal. Over voltage or Dead means the battery has a hardware fault and should not be used, as a faulty battery can overheat or fail suddenly. Stop using the phone and have the battery replaced as soon as possible.

How often should I check my battery health?

Check it once every three to six months if your phone is more than a year old. This gives you a baseline to track whether the battery is aging normally or degrading faster than expected. If you notice a sudden drop in health status or a sharp increase in drain speed, check again within a week to confirm the change.

Does fast charging damage battery health?

Fast charging generates more heat than standard charging, which does speed up battery aging slightly. If you use fast charging every day, your battery may degrade 10 to 15 percent faster than if you used standard charging. If battery longevity matters to you, use standard charging for daily top-ups and reserve fast charging for when you need a quick charge.