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Extending The Lifespan Of A Battery(in years), Help The Current Charge Last All Day, Swollen Battery, Replacing a Battery, Assorted Battery Information

The two big issues with batteries are how long a battery lasts, in years, before it needs to be replaced (battery lifespan) and the amount of time a device runs before it needs to be recharged (battery life). This page addresses each.

All Lithium-Ion batteries can only be charged and drained a certain number of times. Each charge limits the maximum power capacity that the battery can store. That is, each charge destroys the battery capacity, just a little bit. Thus, batteries lose storage capacity over time.

Two things that are useful to know about a battery, on an ongoing basis, are the maximum charge capacity and the number of charge cycles it has gone through. Both give you an idea of how old your battery is. Not only in terms of years/months but old in terms of its expected life span.

The maximum charge capacity is a percentage of the original out-of-the-box charge capacity. On a new battery, it should be 100%. Note that this percentage is different from the percentage typically displayed. For example, if the original design capacity was 6,000mAh and the battery now can only store 4,000mAh (perfectly normal wear and tear) it has lost one third of its original capacity. A computing device, however, will report that the battery is 100% charged when its capacity is 4,000mAh. If your device does not last as long on a "full" charge, this is why.

Keeping a Lithium Ion battery fully charged at all times shortens its lifespan. Batteries last the longest (total lifetime in years, not just making it through the current day) when operating between 30 and 80% charged. A laptop that is plugged in all the time, should be set to never charge over 80% (maybe even 70%). Lithium-Ion batteries are under the most strain internally when they are fully charged or completely empty. They are the happiest at 50 percent charge. When storing a device for a long time without using it, do what you can to prevent the battery from fully draining.

Fast charging degrades Lithium-ion batteries more rapidly than the relatively slow 5-watt chargers of old.

A Brand-X charger could damage the battery. Chargers differ in the controls that limit the amount of current delivered and stop a device charging when the battery is full. An off-brand charger might not have such rigorous safety settings. If too much current is delivered to a battery it can leadi to degradation.

FYI: Charging a phone from a laptop computer does not damage the battery. This does a slow charge which, in general, is a good thing. Leo Notenboom has a good introduction to the concepts of Volts and Amps here Why Does My Phone Charge Slowly on Some Chargers? (Nov 15, 2023)

FYI: A smartphone battery typically works at optimal capacity for roughly two to three years.

FYI: Battery Percentage: It is very helpful on a mobile phone to have the current battery percentage always displayed.
 iOS: Settings -> battery -> battery percentage (requires iOS 16.1 or later)
 Android: search Settings for "Battery Percentage" (tested on Android 12,13,14)

All DEVICES

• Temperature: Keep the device with a battery in an area where the temperature is between 62 and 72 degrees Fahrenheit. The battery can be damaged below 32 degrees and above 95. Excessive heat is the worst of the two extremes. If a device gets noticeably hot while charging, unplug it.
• Does charging your phone to just 80% really make it last longer? by Robert Triggs of Android Authority. September 5, 2024. Yes, it does.

WINDOWS

• Windows does not have a feature to limit the charge of a battery
• Windows 10 and 11 can report the battery Design Capacity, Full Charge Capacity and Cycle Count with the following command
  powercfg /batteryreport
  This generates a lengthy HTML based report in C:\Users\windowsuserid\battery-report.html
  On a 6 year old Thinkpad laptop, the report had no cycle counts. The Design capacity was 49,840 mWh and the Full Charge capacity was 41,350 mWh, so it had lost about 17% of its horsepower. The report also had a section for Battery Capacity History which is a little interesting. Not sure if Windows 8 can create this report. Windows 7 can not.
• Lenovo laptops have offered software that lets you set the maximum charge percentage for years. The software is now called Lenovo Commerical Vantage. It used to be called Think Vantage. Lenovo also has laptop software that lets you see the battery temperature
• Dell has a Power Manager app that I have read lets you set a charging threshold. Their description of the software however is useless.
• HP as a HP Battery Health Manager but it only works on some HP business laptops.
• Asus has a MyAsus app that I have read lets you set a charging threshold. Its a huge app, over 300MB with many many features.
• Nir Sofer makes many excellent, free and portable programs for Windows. His BatteryInfoView program displays assorted technical details of the battery. It is just an information display, it does not change/configure anything.
• If you know of other software to limit the battery charge or display the battery temperature, let me know.

ANDROID

• Search settings for "Battery". No way to know what options will turn up as Android is so different everywhere.
• STOP CHARGING AT 80%
  • For the longest time, Android devices could not be configured to stop charging at anything less than 100%. One exception were Sony phones which have been able to do this since at least 2014. See this Reddit post from June 2023: So glad we can now stop charging at 80% Some Samsung devices also allow this.
  • The December 2024 release of Android on Pixel phones added a new option for "Charging Optimization". It offers the old reliable legacy "Adaptive Charging" or the new sexy "Limit to 80%". Not sure which Pixel phones got this option.
    Settings -> Battery -> Charging optimization
    As before, adaptive finishes charging to 100% right before you normally unplug the device
  • What about the times when you want a full charge? Of course, you could change the setting, but then you have to remember to re-enable it. Or, you can get around the 80% limit by turning the phone off off when you charge it.
  • In December 20204, Robert Triggs of Android Authority investigated what happens when a device is at the 80% limit and still plugged in. Good news. Android devices do what he calls "bypass charging" which means that the battery is ignored and the device is powered from its wired electrical connection. Ignoring the battery minimizes wear and tear on it, yet another way this feature improves the lifespan of the battery. Yet a third benefit is that the device runs cooler. Finally, he points out that the phone will always charge to 80% before bypassing the battery. See Google tells us how Pixel's bypass charging feature works by Robert Triggs of Android Authority. December 12, 2024.
  • See also: Charging optimization in Android 15: What it is and how it works by Nick Todorov for Android Police. October 8, 2024.
• Android 14 on a Pixel offers Adaptive Battery Charging to prolong the life span of the battery. This is a configurable option at:
  Settings -> Battery -> Adaptive Charging
  The phone spies on you to learn your charging habits, a process that takes about two weeks. Then, when the phone expects that a charging session will be long, it delays charging the battery up to 100% until an hour before it expects the charging session to end. Again, the less time a battery spends 100% charged, the better. The Google writeup says this is a Pixel-only feature. It does not exist in Android 10.
• Adaptive Battery on Android 12: "Extend battery life based on your phone usage" and "Adaptive Battery may reduce performance and background activity. Some notifications may be delayed."
• Adaptive Battery on Android 10: "Limit battery for apps that you don't use often" and "To extend battery life, Adaptive Battery limits battery for infrequently used apps. Your phone will learn how you use apps over time. Notifications may be delayed for these apps".
• Samsung: Settings -> Battery and device care -> Battery -> More battery settings
  The Protect battery option limits charging to 85%. You can even schedule battery protection to turn off on the days when you normally need a full charge. The scheduling is at
  Settings -> Modes & Routines -> Routines. Like Google and Apple, Samsung has an Adaptive battery feature that limits full charging based on your habits.
• Samsung Galaxy phone: to limit the battery to 80%
  Settings -> Battery -> Battery Protection -> Maximum
• Samsung tablet running Android 14
  • Settings -> About tablet -> Battery information -> shows the battery capacity in mAh
  • Settings -> Battery -> Battery protection - adjusts the charging behavior to extend the lifespan of the battery. The options are basic, adaptive and maximum. Maximum stops charging at 80%
  • Settings -> Battery -> Charging settings -> Fast charging. Probably best to turn this OFF
• A Samsung tablet running Android 10 showed the battery capacity in mAh, but no cycle count
• While Android may not let you manually set a battery charge limit, there is an automatic, non-configurable option on Pixel phones that stops charging at about 70%-80%. See Get the most life from your Pixel phone battery for details. This kicks in when the phone detects
  -- Continuous charging for more than a few hours under high temperatures
  -- Continuous charging for more than several days
• Cycle count and battery wear: Android devices are all different, so perhaps search the Settings for "battery". And, be sure to look in the "About phone" section of the Settings.
  • Settings->About phone: Pixel 3 Android 12 has no battery information
  • Settings->About phone->Battery information: Pixel 5 Android 14 shows Cycle count
  • Settings->About phone->Battery information: Pixel 6 Android 14 shows Cycle count and the date of manufacture
  • Samsung does not report the cycle count as far as I can tell
  • Battery info apps: Accu​Battery from Digibites and Battery by MacroPinch.

iOS, iPhone, iPad

• The iPhone 15 was the first iPhone that allowed users to stop a battery charge at less than 100%. Finally finally, an iPhone gets a feature that laptops (Lenovo at least) have had for years and years. See How to turn on 80% charging limit on the iPhone 15 to save battery health by June Wan for ZDNet (September 22, 2023). I do not have access to an iPhone 15. One article said the setting is at:
  Settings -> Battery -> Battery Health & Charging -> Optimized Battery Charging -> turn on "80% Limit"
  another said: Settings -> Battery -> Charging Optimization -> select the 80% limit
• iOS17.4 March 2024 iPhone: The Battery section in the Settings app has changed. There are two new menus: "Battery Health" and "Charging Optimization". Tap on either of these for more details. This is the first time Apple has told users whether the battery health is normal or not. Not sure if this applies to iPads too.
• To see how much charge an iPhone can currently take (vs. when it was new)
  Settings -> Battery -> Battery Health & Charging -> Maximum Capacity percentage
  Note that Battery Health information is not available on iPads (last checked with iOS 17.5)
• Cycle Count: While, the maximum capacity percentage (above) is the more important number, it can also be helpful to know how many charge cycles a device has been through. I have read that an iPhone is designed to keep 80 percent of its original capacity for up to 500 charge cycles before the battery is considered worn. Not that it won't work at 501.
  • iPhones did not display the Cycle Count until the iPhone 15 where you can see it with:
    Settings -> General -> About -> Cycle Count
  • To see the cycle count on older iPhones, you can use the Mac app CoconutBattery
  • This Reddit article from 2019 has a hack to find the Cycle Count in the Analytics data that iOS collects.
  • As of iOS 17, you can see the collected Analytics data (i.e. Apple spying on you) at
    Settings -> Privacy & Security -> Analytics & Improvements
    The article above says to look for a file name in the format: log-aggregated-yyyy-mm-dd-xxxxxx.ips. Find the most recent such file and open it. Its a plain text file and contains the cycle count. To have the system create this file, the option "Share iPhone Analytics" must be enabled. If you want to minimize Apple spying, turn this option off. If you do have it off (I do) then iOS still creates many many files, but it does not upload them to Apple. They just keep accumulating (as of iOS 17.5). Among the many files it creates are some with a name like: LowBatteryLog-yyyy-mm-dd-999999.ips. No doubt there is detailed battery info here, but it is not in an easily read format.
• November 14, 2023: Jared Newman published instructions for using a smart plug and the iOS shortcuts app to limit how full the battery is charged: How to limit iPhone charging levels with a smart plug. His example uses a TP-Link Kasa plug and he starts charging at 80% and stops at 85%. What if you want a full charge? He says to just plug the iPhone into a different charger. He does not say anything about iPads.
• iOS 13 and later have an option to optimize the charging of the battery with the intention of extending the life span of the battery. See About Optimized Battery Charging on your iPhone from Apple. They say it was published September 21, 2023, but that is not true. I first ran across this article in January 2022. Apple does exactly what Google does, the phone takes some time to learn your charging habits and then stops a re-charge at 80% for a while, only finishing the re-charge up to 100% just before it expects you to unplug the device. The option is at
  Settings -> Battery -> Battery Health & Charging -> Optimized Battery Charging
  This must be an iPhone only thing, there is no Battery Health section on an iPad running iOS 15.6.
• iPhone Battery and Performance from Apple. Published May 18, 2023. No updates since.
• Check the iPhone battery health and usage from Apple. For iOS 15, 16 and 17.
• January 2022: The battery health information Apple provides in the iOS settings ( Settings -> Battery -> Battery Health or maybe Battery Health and Charging) is meaningless according to Adrian Kingsley-Hughes of ZDNet: Confirmed: Your iPhone is lying to you.
• Swappa sells used iPhones. According to their note (What are the Apple Battery Health requirements on Swappa?), if the battery capacity is below 80% it will be disclosed. They also document some of the messages in the Battery Health & Charging screen of an iPhone: Apple Battery Health explained: Capacity and Capability.
• November 2019: iOS 13.2 tips: Bad iPhone battery life? Here's how to diagnose and fix battery drain issues by Adrian Kingsley-Hughes

macOS

• AlDente is a menu bar tool that can limit the maximum charging percentage (Alternate link). It requires MacOS 11 Big Sur or later. There is a free version. As of Nov 2023, the paid version is $22.
• coconutBattery from Coconut-Flavour shows the battery capacity percentage (current max charge vs. out-of-the-box max charge), the number of charge cycles and the battery temperature. And more: it shows a history of the state of your battery. There is a free version and a $13 Plus version.
• Battery Health from FlipLab is available both in the Mac App Store and on their website. The version in the Mac App Store was last updated in September 2018. It requires macOS 10.7 or later and is free, but there is a Power History feature that they charge for. It shows battery capacity, power usage and the charge cycles. The website version is newer, it requires OS X 10.10 or later. It costs $10 and shows charge capacity (which is calls Health), battery temperature and the cycle count. The energy hogs feature allows you to prolong battery life by closing down apps that are detected as consistently using a high amount of energy.
• 4 Ways to Limit MacBook Charge to 80% for Battery Health by Ritik Singh. Last update Nov 3, 2023. Originally written Jan 2022. The article has detailed step by step instructions, with pictures, for installing AlDente, BatteryStatusShow and Charge Limiter. BatteryStatusShow comes in a portable version which does not have to be installed. Charge Limiter is open-source. Also mentioned are OS features: macOS 10.15 Catalina introduced Battery Health Management that throttles the charging to reduce the premature wear of the battery. macOS 11 Big Sur added "Optimized Battery Charging," which tries to keep the battery at 80%. The same feature exists in macOS 12 Monterey.
• According to the article above by Ritik Singh, you can check the battery condition and cycle count on a MacBook using the System Report in macOS: click the Apple icon in the menu bar -> About this Mac -> System Report -> Power and check the Battery Health column.
• If battery charging is paused or on hold on your Mac from Apple. November 8, 2023. Applies to macOS Big Sur and later. The Optimized Battery Charging feature id designed to improve the lifespan of the battery by reducing the time the laptop spends fully charged. It delays charging past 80% in certain situations. As with other devices on this page, the computer learns your charging routine and aims to ensure that the Mac is fully charged when unplugged. There are instructions for turning the feature off.
• Feb 13, 2020: Apple says its MacBooks retain 80% of their charge capacity after 1000 charge cycles. That has been the case with most models since 2009. From How to test a MacBook battery: see if it needs replacing & replace it by Karen Haslam for Macworld.
• April 20, 2023: "Apple does provide a warranty for laptop batteries that's fairly generous: if your battery drops below the ability to retain an 80 percent charge within its first year (or within three years with AppleCare+), Apple replaces it for free. Outside of that period, the cost in the U.S. appears to be a flat $159 for MacBook Air models and $249 for MacBook Pro models." The quote is from here: Should you replace your MacBook battery or pay Apple to do it? by Glenn Fleishman for Macworld. The answer very much depends on the age of the computer. The batteries are easier to replace on older MacBooks.
• Feb 13, 2020: How to test a MacBook battery: see if it needs replacing & replace it by Karen Haslam for Macworld. Press the Alt/Option key -> click the battery charge icon at the top right of the desktop near the clock. The battery can be in 1 of 4 states: Normal (all good) , Replace Soon (this is a mere warning rather than a demand) Replace Now (bad) and Service Battery (bad).
• For Mac laptops with Intel CPUs, there is a battery feature in the OS.
  See About battery health management in Mac notebooks from Apple. Published: January 24, 2023.
• To show the percentage of battery charge in the menu bar
  Apple menu -> System Settings -> Control Center in the sidebar-> Battery -> Show Percentage
  From the macOS User Guide: Monitor your Mac laptop's battery which has customized content for many different macOS releases.
• FYI: November 13, 2023. How to fix a MacBook that won't charge by Karen Haslam of Macworld. Long article that touches many bases.
• FYI: System Settings -> Battery and Check -> see the advice about Battery Health
• FYI: August 16, 2021: How to check the keyboard, mouse, and trackpad battery level in macOS by Glenn Fleishman for Macworld. Apple does not display the charge of Wirelessly connected peripherals in an obvious place. Some suggestions from the article
  macOS Catalina or later: Control Center -> Bluetooth
  Any version of macOS: Open the Bluetooth preference pane
  Open the Keyboard, Mouse, or Trackpad preference panes
• Maximizing Battery Life and Lifespan from Apple has sections for all their hardware devices. But, it is not dated, so no way to know how old it is.
• EH: Check the condition of your Mac laptop's battery from the Apple macOS User Guide. All this results in is either that the battery is functioning normally or that it needs servicing. No other information. To see it in Sonoma 14: Apple menu -> System Settings -> Battery in the sidebar

CHROMEBOOK

• The information here was verified on ChromeOS version 118 in November 2023
• There is a pre-installed Diagnostics app that you can run by clicking on the Launcher button (bottom left corner) and searching for "diagnostics". The left side vertical colum has three sections, but the default section, System, is what we want. This shows the battery health, as a percentage, and the Cycle count.
• More details are available from the command line. Hit Hit Ctrl + Alt + T on the keyboard to open crosh, the terminal app. Then type
  battery_firmware info    (underscore between battery and firmware, space between firmware and info)
  to see the battery manufacturer, the serial number, the design capacity in mAh, the last full charge in mAh (this can verify the percentage from the Diagnostics app), and the battery Cycle count.
• Turn on "Adaptive Charging" as per: How to keep your battery healthy with Chromebook Adaptive Charging by Robby Payne of Chrome Unboxed. December 19, 2024. As with Android, Adaptive Charging on a Chromebook learns your usage patterns and only charges to full capacity when you truly need it. The rest of the time, it limits the charge to around 80%.
  Click the clock in the bottom right corner of the screen -> click the gear icon -> search for "Adaptive Charging" -> turn it on

All DEVICES

1. Dim the display and use a dark background.
2. Turn off Wi-Fi and 4G/5G and BlueTooth and turn them on, only when needed. Ditto for Location/GPS.
3. Use Low Power Mode when available (more below)
4. Limit the activity that apps can perform when they are running in the background (more below)
5. Many games use a lot of computing horsepower, so don't play them.
6. Batteries drain faster when hot, so try to keep the device cool.
7. Have an available external battery.
   For laptops and Chromebooks, this article recommends three models priced from $47 to $150:
   The Best Power Banks for Laptops With USB-C by The WireCutter. Last Updated March 15, 2024.
   For phones and tablets, this article recommends three models from $39 to $70:
   The Best Portable Chargers and Power Banks for Phones and Tablets by The WireCutter. Last Updated July 24, 2024.

IPHONE LAST ALL DAY

1. Dim the display and/or dark background: Settings -> Display & Brightness -> use the slider bar
2. To insure that you get the screen brightness you want, turn off the auto-brightness option at
   Settings -> Accessibility -> Display & Text Size -> disable Auto-Brightness
3. Turn off Wi-Fi and/or Bluetooth and/or 4G/LTE/5G if not needed
4. Low Power Mode on both iPhone and iPad
   Settings -> Battery -> Low Power Mode
   I have read that Low Power Mode will automatically kick in when the battery falls below 20%. Manually turning it on only works if the battery is below 80%, above 80% Apple knows what is best for you and they will ignore your wishes.
   From Apple: Use Low Power Mode to save battery life on your iPhone or iPad Updated: May 21, 2024 and Sept 26, 2023
   From Apple: Use Low Power Mode to reduce power usage on iPhone for iOS 17
5. Limit the activity that apps can perform when they are running in the background. You need to this every now and then as newly installed apps seem to default to being allowed to run in the background.
   iOS 18: Settings -> General -> Background App Refresh -> Choose which apps get to refresh periodically on their own and which ones get updates only when you are actively using them.
6. Stop Siri from listening for your command:
   iOS 18: Settings -> Siri -> "Talk to Siri" -> turn OFF
7. Turn off AirDrop: Settings -> General -> AirDrop -> Receiving Off
8. The iPhone 14 and 15 have an Always-On display option. Turn that off
   Settings -> Display & Brightness -> disable Always On
9. Turn off Location: Settings -> Privacy - >Location service
10. Turn off Find My: Settings -> Your Name -> Find My -> Find My iPhone -> disable it
11. If you have a phone that is able to run Apple Intelligence, then turn it off
    iOS 18.1: Settings -> Apple Intelligence & Siri
12. And FYI: Don't turn off ProMotion to save iPhone 15 Pro battery life by Ben Lovejo for 9to5Mac. November 16, 2023
13. Article: 10 best ways to actually save iPhone battery life by D. Griffin Jones for Cult of Mac. One tip: use Wi-Fi whenever possible as it takes less energy than 4G LTE, and much less than 5G.
14. Article: How to Squeeze More Time Out of a Failing Phone Battery by J. D. Biersdorfer for the New York Times. August 28, 2024. Covers both iOS and Android.

ANDROID LAST ALL DAY

• Dim the display. With Android 14 or 15 on a Pixel: swipe down twice from the top of the screen, move slider left/right. Or,
  Settings -> Display -> set a Brightness Level and turn off Adaptive brightness
• Reduce the "Screen timeout". Search for it in Settings. On an Android 15 Pixel, its in the Display and Touch section.
• Turn off Wi-Fi and/or Bluetooth and/or 4G/LTE/5G if not needed
• Low Power Mode:
  Maybe swipe down from the top and look for Battery Saver
  Maybe Settings -> Battery
  Maybe Settings -> Battery and Device Care -> Battery -> Power Saving mode
• Terminate apps running in the background that you don't need. On Android 13, 14 and 15, you can see which apps, if any, are running quietly in the background. Swipe down twice from the top of the screen. At the bottom of the screen will be a very short description of one of the apps and the number of running apps in a circle. See a screen shot of what it looks like. The example had only one background app, the Mullvad VPN. If you click on this information you get a more detailed explanation. See a screen shot of that.
• Limit the activity that apps can perform when they are running in the background
  Samsung Android: Settings -> Battery and Device Care -> Battery -> Background Usage Limits
• BATTERY SAVER FEATURE
  • Documented here: Use Battery Saver on a Pixel phone by Google. They say "To make your battery last longer, you can set Battery Saver to turn on automatically. You can also turn on Battery Saver at any time. To save even more power on your device, you can turn on Extreme Battery Saver. While Battery Saver is on, a Pixel phone with 5G uses 4G service." Among the changes: it turns on the Dark theme, limits or turns off background activity, some visual effects, and some network connections.
  • Android 14, 15 on Pixel: Settings -> Battery -> Battery Saver
  • Android can turn Battery Saver Mode OFF and ON based on a configurable battery percentage.
  • History: The Battery Saver on/off option in Android 12 was misleading. "On" meant always on, no matter what, it did not mean enable the Schedule. In Android 10 there was a clear and obvious blue button that turned on Battery Saver.
• Article: How to Squeeze More Time Out of a Failing Phone Battery by J. D. Biersdorfer for the New York Times. August 28, 2024. Covers both iOS and Android.
• Article: I changed 12 settings on my Android phone to drastically improve battery life by Max Buondonno for ZDNET November 2, 2024. Good article. Some of the suggestions are off the beaten path. They include: turning off keyboard sounds and haptics, reducing notifications, reducing the refresh rate of the screen (that never would have occurred to me) and turning off the constant listening for a "Hey Google" command.
• From Samsung for their Galaxy phones: Battery Life Optimization undated
• From Google: Get the most life from your Android device's battery undated
• From Google: Fix issues with your Pixel phone battery (undated) about the Battery diagnostics feature available on Pixel 6 and later phones. It deals with: battery draining too quickly, phone is very warm, problem with charging or something else. Links to many articles. Battery Diagnostics are at: Settings -> Battery.
• From Google: Fix battery drain problems on a Pixel phone undated
• From Google: Check battery level on your Pixel phone undated

macOS LAST ALL DAY

• Dim the display on a MacBook laptops with the F1 and F2 keys
• Turn off Wi-Fi and/or Bluetooth and/or 4G/LTE/5G if not needed. This can be done in either the Settings app or the top menu bar.
• macOS Sonoma has a low power mode: System Settings -> Battery -> Low Power Mode.
• Battery Health from FlipLab is $10 on their website. It has an energy hogs feature allows you to prolong battery life by closing down apps that are detected as consistently using a high amount of energy.
• How to save MacBook battery life by Karen Haslam for Macworld. February 2020. Some topics: How long is a Mac battery supposed to last?, Find out what’s using up your battery, Change Energy Saver Preferences, Use dark mode, Stop background activity and Turn off power hogging features.
• Close apps
  1. That you are not using
  2. That are battery hogs: Apple introduced a feature in OS X 10.9 Mavericks - the ability to see what apps are using up your battery. In 10.9 or later, open Activity Monitor (Applications/Utilities) -> go to the Energy tab and sort by "Energy Impact" to see the biggest users of the batter power.
  3. That are CPU hogs: Activity Monitor can reveal CPU hogs -> on the CPU tab -> All Processes -> sort by CPU usage
• Article: Maximizing Battery Life and Lifespan from Apple has sections for all their hardware devices. But, it is not dated, so no way to know how old it is.

CHROMEBOOK LAST ALL DAY

• There should be Function keys on the keyboard to lower the screen brightness.
• Turn off Wi-Fi and/or Bluetooth if not needed
• Pro Tip: A portable power bank can double your Chromebook usage on the go by Kevin C. Tofel (January 28, 2023). What to look for in terms of both battery capacity (milliamp hours o mAh) and amperage (speed of charging).
• This June 2023 article by Robby Payne of Chrome Unboxed, The Chromebook Battery Saver is taking shape to allow better battery life on the go is about a soon to be released Battery Saver feature.

WINDOWS LAST ALL DAY

• There should be Function keys on the keyboard to lower the screen brightness.
• Turn off Wi-Fi and/or Bluetooth and/or 4G/LTE/5G if not needed. Maybe use Airplane Mode.
• How to preserve your battery charge on a Windows 11 laptop by Lance Whitney for AskWoody.com April 15, 2024. Windows 11 has a Battery Saver Mode that lowers the screen brightness, disables certain background tasks, and takes other actions to preserve the charge.
• Windows 11 has a low power mode:
  Settings -> System > Power & battery
  It also has a "Best Power Efficiency" mode.
• Windows 10 Settings -> System -> Battery. Configure Battery Saver as desired.
• Close apps
  1. That you are not using
  2. That are battery hogs:
     Windows 10 Settings -> System -> Battery -> check the Battery usage per app section
     Windows 11 Settings -> System -> Power & Battery -> Battery usage -> Battery usage per app
  3. That are CPU hogs: Personally, I am a huge fan of Process Explorer, a free program from Microsoft. It has no battery related functions, but it does show CPU usage and lets you easily find the software using the most CPU horsepower now, or in the recent past. Depending on Windows authority levels, you may be able to kill or freeze/suspend a heavy CPU-using process.
• Turn off Nearby Sharing
  Windows 11: Settings -> System -> Nearby Sharing
  Windows 10: Settings -> System -> Shared Experiences -> Nearby Sharing. While there, also turn off "Share across devices"