Yes, phone batteries drain even when not in use due to background processes, connectivity maintenance (Wi-Fi, cellular, Bluetooth), and system services. Typical causes include active push notifications, location tracking, poor signal searching, and aged batteries that hold less charge over time.
Yes! It is absolutely normal for a phone's battery to drain by 10% overnight. It happens due to all the background processes going on in the phone. If you really want to save battery, then you must turn on airplane mode, and block the background processes before you go to sleep.
Depending on your device, you can:
Wi-Fi, Bluetooth, and GPS can drain your battery even when idle. To save power, turn off these features when not in use. On most mobile devices it's as simple as accessing your notification drawer from the Home screen and tapping the settings to disable them.
By shutting down your phone at least once a week, you reduce the risk of unauthorized access, data leaks, and hacking attempts. It's a small but effective step in keeping your personal information secure. The NSA recommends turning off your smartphone at least once a week.
What Are the Main Causes of Phone Battery Drain?
The 20/80 battery rule suggests keeping lithium-ion batteries (in phones, EVs, etc.) charged between 20% and 80% for daily use to slow degradation and extend overall lifespan, avoiding the stress and heat from frequent full charges (100%) or deep discharges (near 0%). While not strictly necessary for short-term use, following this guideline minimizes battery strain, leading to better long-term health, though modern devices have built-in optimization features.
It varies based on the battery, but for the most part it's because the chemical reaction used inside batteries to create the electricity can't really be fully turned off. Even if there's nothing connected to the battery. There's still some residual activity inside that uses up potential energy.
If your phone is being monitored remotely, you might notice your battery draining quickly, spot unfamiliar apps, or your camera, microphone, or location turning on when you're not using them.
For Android Users: The steps might be a little different on your phone, but here's how it usually works: Open Settings, tap Battery, and then Battery usage. This will show you a list of your apps, with the ones using the most battery at the top. It's an easy way to spot which apps are the problem..
If you have a new phone that you're using the way a typical phone would be used, your battery should work at 80% and above for 2-3 years. You can keep your battery lasting even longer by keeping it protected from extreme cold and heat and charging it appropriately.
Here are some common culprits: Background Apps: Apps running in the background consume significant power. Screen Brightness: High screen brightness settings can deplete your battery fast. Location Services: Continuous GPS usage drains battery life.
Limit internet connectivity and location access - Minimising mobile data, WiFi, Bluetooth, location services when not needed can help conserve battery. Turn on Airplane mode when mobile data isn't required. Also avoid battery draining apps like cameras and games. Don't keep lots of apps running in the background.
Experts suggest that turning your phone off can help preserve your battery for longer. But don't bother turning off your phone if it will only be off for a short period of time. The battery-boosting benefits of powering off only take effect if you power off for a few hours or more.
Here are some of the most common ones for poor battery health:
Leaving a device plugged in at 100% charge won't instantly ruin it due to modern battery management systems (BMS) that stop charging, but it creates a high-stress state, leading to "trickle charging," heat, and faster long-term battery degradation (reduced capacity) over time, especially if done regularly, though a single overnight charge is usually fine for newer devices. The primary risks are heat generation and unnecessary power draw, but some older devices or components could overheat, potentially posing a fire risk if a fault develops.
Fire and Overheating Hazards
Fire departments respond to phone calls about fires every year. Most involve phones left on beds, couches, or buried under pillows and blankets. Your phone case makes this worse. That protective cover traps even more heat during charging.
Your phone might die quickly due to background apps running, constant push notifications, or syncing services. Weak network signals can also cause your phone to work harder, draining more power. Check your battery settings to see which apps are draining power even when idle.
The 80/20 battery rule suggests keeping lithium-ion batteries (like in phones, laptops, EVs) between 20% and 80% charge for daily use to maximize long-term health and lifespan, avoiding the stress of full discharges (below 20%) and prolonged full charges (above 80%) that degrade battery chemistry faster, though modern devices have built-in optimizations. It's a guideline, not a strict law, balancing battery longevity with convenience, as charging to 100% or dropping below 20% is fine for occasional use.
How Long Does an Unused Battery Last? Most unused alkaline batteries will last between five and 10 years, while Ni-MH (nickel metal hydride) batteries have a shelf life of three to five years of non-use.
A phone's max battery capacity often lasts two to three years or around three hundred to 500 charge cycles. This is the estimation for branded and off-brand models. Phones that are more than three years old tend to carry less charge or will rapidly lose power than before.
While keeping your phone between 20% and 80% charge can extend battery lifespan, occasional full charges are not detrimental. In essence, today's smartphones are designed to handle 100% charging safely, and adhering to good charging practices can help maintain battery health for the long term.
Store it half-charged when you store it long term.
Therefore, we recommend the following: Do not fully charge or fully discharge your device's battery — charge it to around 50%.