Battery Guru: Battery Health

Contains adsIn-app purchases
4.4
34.1K reviews
Content rating
Everyone
1M+
Downloads
Content rating
Everyone
In-App Purchases
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About this app

Android shows you the basics. Battery Guru goes deeper.

Get your actual battery capacity in mAh, track health degradation over time, measure real charging current, monitor temperature and see everything on an always-on display or homescreen widget. Battery Guru builds on top of Android to give you the full picture.

🔋 Battery Health and Capacity
Your phone shows a percentage. Battery Guru shows you whether your 4000 mAh battery still holds 4000 mAh or has quietly lost 20% of its capacity over time.
- Actual battery capacity in mAh compared to original design capacity
- Battery health percentage and capacity loss tracked over time
- Battery wear analyzed per charging cycle
- Charging cycle count from system data or calculated from your session history
- Maximum temperature recorded during each charging session

Charging Speed and Current
Not all chargers deliver what they promise. Battery Guru measures the real current flowing into your battery so you can compare chargers and cables by actual performance.
- Live charging current in mA and power in Watts
- Voltage readings in mV
- Estimated time to full charge with screen on and screen off shown separately
- Complete charging history with start time, end time and capacity per session
- Compare chargers and cables by their real measured output

📉 Battery Drain and Usage
When your battery drains faster than expected, Battery Guru shows you exactly where the charge is going.
- Screen on time, screen off time, awake time and deep sleep time
- Battery usage by app running in the foreground
- Wakelock monitor to identify apps and system processes keeping your device awake in the background
- Alerts when abnormal battery drain is detected
- Discharge rate and usage pattern history over time

🌡️ Temperature Monitoring
Heat is the leading cause of permanent battery damage. Battery Guru tracks temperature continuously and alerts you before harm is done.
- Real-time battery temperature with 24-hour history graph
- Custom high and low temperature alarm thresholds
- Minimum, maximum and average temperature per session

🔔 Alarms and Notifications
- Full charge alarm so you unplug at the right time and avoid overcharging
- Low battery alarm before you run out
- High battery drain warning when something unexpected is consuming power
- Temperature alarm for both overheating and cold conditions
- Status bar notification with customizable icon showing percentage, temperature or both
- Do Not Disturb schedule so alarms respect your sleep hours

📲 Always-On Display
See live battery stats on your lock screen without touching your phone. Battery Guru includes a fully featured always-on display built for AMOLED and OLED screens.
- Battery level, charging current, temperature and voltage on your lock screen
- Clock, notification icons and media playback controls
- Fully customizable layout and content
- OLED burn-in protection with automatic pixel shifting
- Auto-dim after a configurable time to preserve your screen

🖼️ Widgets and Overlays
- Homescreen widget showing battery level and temperature at a glance
- Widget with clock for combined battery status and time
- Draggable floating overlay with live battery stats over any app
- Overlay displays current, temperature, voltage and more in a compact view

🔵 Bluetooth Device Battery
- View the battery level of your connected Bluetooth devices inside the app

💎 Pro Features
- Ad-free experience
- Full session history for long-term battery health analysis
- Advanced overlays and complete health history
- Free premium: watch one short rewarded ad for 24 or 48 hours of premium access, available unlimited times

Battery Guru reads data directly from your device battery system. It measures and displays accurate values only. It does not claim to modify your battery, speed up charging or extend battery life in any way.

📧 Contact & Support
support@batterymentor.com
Battery health monitor with mAh, charging speed, always-on display and alarms.
Updated on
Aug 3, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
This app may share these data types with third parties
App activity, App info and performance, and Device or other IDs
This app may collect these data types
App activity, App info and performance, and Device or other IDs
Data is encrypted in transit
Data can’t be deleted

Ratings and reviews

33.2K reviews
Jimmy DeCoster
May 22, 2026
It will completely fail to log any data for days on end, then when you need it to diagnose a sudden battery drain, there's nothing logged except the seconds since you launched it. Also refuses to acknowledge full charges, complaining that I haven't fully charged since December even though last night I disabled battery optimizations to get a full charge and charged from 1% to 100%. I even had a notification saying it was fully charged. But when it works, it works great!
3 people found this review helpful
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Paget96
May 23, 2026
Background restrictions on some devices can stop Battery Guru from recording charging sessions, battery statistics, and usage details correctly. Please check dontkillmyapp and enable background activity, autostart, and remove battery restrictions. If the full charge detection still looks wrong, contact support@batterymentor.com with screenshots.
Anthony C
May 21, 2026
The app is effective & receives frequent updates. However, the subscription route is not cost-effective for my needs. Email support is available, but it could be more consistent with follow-up responses. One drawback is that it appears to reduce Deep Sleep mode by approximately 10% when the device is idle, which is likely due to its aggressive background runtime.
81 people found this review helpful
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Paget96
March 27, 2026
Thank you for an update and feedback. Screen time share for deep sleep and awake time will be added as soon as we bake some new design around it, as just adding new row makes it confusing. Stay tuned for more info. 🤗 Edit: Will be added with next update. 😊
Mark LaFlamme
November 7, 2025
Out of control ads. I wish there was a trial period without them because it's near impossible to use with the jarring pop ups screaming at you. I don't mind paying for a quality app, but when my main reaction to one is annoyance, it's time to move on. UPDATE: Okay, premature review. I hadn't come across the options for 24 and 48 hour subscriptions. I'll give that a look. That seems a decent way to try out the app without distraction.
4 people found this review helpful
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Paget96
November 7, 2025
Hello, you can remove ads for free and get premium for free. Check 24h and 48h subscription. It's free and can be used unlimited times. 😊 Users love this feature. Edit: Opt in ads feature has a minor bug, fix is coming within 24h

What’s new

New Material 3 Expressive design, with bigger numbers, new card shapes and a true black AMOLED theme.

Battery health is more accurate, no longer gets stuck, and adds a forecast based on your own battery's fade.

Fixed discharge reading around half on some phones, plus a better screen-on versus screen-off split.

Battery Mentor now lists phones by battery size and supported Android versions.

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