Over the years, Windows PCs have gotten considerably more capable of squeezing a full day of work out of a laptop battery, but there's still a certain level of anxiety that comes with disconnecting from a fixed power source. Reducing that anxiety doesn't require drugs or meditation. All you need is some knowledge about how your PC works with Windows 10.
This article assumes you're using a portable PC designed for Windows 10, with a modern processor that's capable of entering the Connected Standby state, running a recent Windows 10 release. Assuming you meet those criteria, all of the following steps should work just fine.
1. Create and save a battery report
Windows 10 includes a command-line tool that generates a detailed report showing information about battery usage for the current device over time. This information is saved as an HTML document that you can view in any web browser.
Each battery report includes both tables and charts showing recent usage, usage history, battery capacity over time, and battery life estimates. Even if you're not deeply technical, you should be able to gather useful information from this report.
To generate a battery report, start by opening a Command Prompt session: Press Windows key + R to open the Run dialog box, type cmd, and press Enter. Then, in the Command Prompt window, type the following commands, pressing Enter after each one (be sure to include the spaces between commands, arguments, and switches):
That sequence generates the battery report and saves it in the current user's Temp folder. To open the report immediately from the Command Prompt window, type the full report name, battery-report.html, and press Enter. (To save a few keystrokes, type batt and then press Tab to autocomplete the full filename.)
Each time you generate a new battery report, it overwrites the previous one. Any information that's more than a few weeks old gets summarized into aggregate values covering a full week or month. To save the daily details, open File Explorer, navigate to the %Temp% folder, move the battery report file to your Documents folder, and give it a new name.
2. Check your battery's current capacity
Every portable PC ships with one or more batteries, whose capacity is measured in milliwatt hours or mWh. Over time, as you charge and discharge a laptop battery, that capacity degrades. Eventually, the degradation can be severe enough that the laptop is essentially unusable unless connected to a power source.
The Installed Batteries section at the top of the battery report shows the design capacity of each available battery as well as the current full-charge capacity, and the Battery Capacity History section shows the change in both values over time.
The best way to extend your battery's life is to avoid storing or using it in high-temperature environments; unlike older battery technologies, you don't need to worry about partial discharge cycles, although it helps to do a full discharge-recharge cycle occasionally (once a month or so).
3. Analyze your observed usage over time
For as long as I can remember, PC manufacturers and independent reviewers have struggled to come up with measurements of battery life that can be used to compare the performance of different devices. Typically, those schemes measure either video playback or some form of cycling through web pages and various apps.
Which is all well and good, except that you would probably like to know how much of a drain your particular workload will place on your laptop battery. And, of course, that measurement will vary depending on the apps you're using, the quality of your network connection, and other variables. That's why measuring actual observed usage is more important than any synthetic benchmark.
You'll find details of battery drains in the battery report, which shows a graph and table covering the last three days, under the Battery Usage heading.
The graphical portion shows time (from left to right) and charge/discharge activity (up for charging, down for discharging). The table below it provides details about each change from active use to Connected Standby while running under battery power.
The real key to interpreting this data is knowing what you were doing in each session. For example, in one such report I had two Active sessions, each roughly an hour in length, with one session consuming 7% of battery and the other taking about twice as much. Knowing what you were doing in each session helps you see, quite literally at a glance, how battery-intensive each specific activity is.
4. Estimate your average battery life
The Battery Life Estimates section of each battery report delivers exactly what it promises: an estimate of how much total battery life you would get in a session based on your observed activity.
These estimates are generally quite accurate, and they help to see at a glance just how much of your battery is being used in each session based on the work you're doing.
Occasionally, I've noticed that the battery report can record an anomalous bit of data that is startling to see, as in one session where Windows 10 told me, in all seriousness, that I could expect just over 980,741 hours of laptop use. Needless to say, that estimate turned out to be unreliable and, annoyingly, it made the average battery life calculation less than helpful.
5. Identify which apps are affecting your battery life
The battery report isn't the only useful bit of system information that Windows 10 provides. A separate report allows you to zero in on power usage on an app-by-app basis. To find this listing, go to Settings > System > Battery and then click See Which Apps Are Affecting Your Battery Life.
Use the drop-down menu at the top of the page to filter the list so that it shows activity over the past six hours, a full 24 hours, or the previous week.
This list is a really powerful way of identifying apps that are using more than their fair share of your battery. Armed with these details, you can modify your app usage or check for additional power-saving options for individual apps. (I've learned, for example, that it's useful to close TweetDeck before putting this system to sleep.)
6. Adjust power and sleep settings
Knowing how your Windows 10 PC uses battery power is one thing. Knowing how to control its power usage is quite another.
To open the basic power management options, go to Settings > System > Power & Sleep. There, you can adjust the interval after which Windows turns off the display and puts the system into sleep mode when connected to a power source and when running on battery.
The display is one of the most power-hungry pieces of a modern PC, so turning it off as quickly as possible is a great energy-saving move. Likewise, there's little penalty in aggressively setting sleep thresholds. Modern processors are very efficient at managing sleep states and can resume in literally an instant.
For the full set of power management options, click the small Additional Power Settings link. That action takes you to the old Windows 7-style Control Panel, where you can define what happens when you press the power button or close the lid of your laptop.
7. Enable hibernation
During the course of your workday, putting a laptop to sleep and resuming as needed is the correct strategy. But if you're planning to step away from work for longer than a few hours, hibernation is the way to go. I rediscovered this fact on my Arm-powered laptop after stuffing it into my bag before a trans-Atlantic flight. Upon landing, I discovered that the battery was nearly completely discharged and my laptop bag was uncomfortably warm. Oops.
When you tell a Windows 10 PC to hibernate, it saves the current state of memory to a file and then shuts down, which means there's no chance of "hot bag syndrome"; when you press the power button to restart, Windows reloads the contents of memory from the hibernation file, allowing you to resume right where you left off.
If the Hibernation option is turned on, you can use the advanced power options to specify that you want to hibernate automatically after a specific interval in sleep mode. From the Power Options section of Control Panel, click Change When the Computer Sleeps, and then click Change Advanced Power Settings and expand the Sleep heading to display the setting shown here.
You can also assign the Hibernate option to actions like closing the lid or pressing the Power button.
If the Hibernate option's not available, open a Command Prompt session (cmd.exe) and run this command:
8. Learn the quick Shutdown secrets
Most often, you'll transition between the Active and Connected Standby power states by closing the laptop's lid, pressing the power button, or using the Power menu. But there's another, arguably easier option: the Shutdown command.
You can use this tool from a Command Prompt (Cmd.exe) window, or from the Run dialog box, or even from the Search box. Shutdown has lots of command-line switches, as you can see if you run its built-in help option:
But a few of those switches deserve to be on your shortlist. Run shutdown /r to restart after a brief grace period, and use shutdown /h to hibernate immediately.
9. Use the Battery Saver option for maximum power savings
Windows 10 includes a Battery Saver option that instantly turns off activities that chip away at battery life, such as push notifications and background activity for some apps. Turning on Battery Saver can dramatically increase your battery life and has the extra bonus of reducing distractions as you work.
By default, Battery Saver is set to turn on automatically when your remaining battery capacity drops below 20 percent. You can change this setting by going to Settings > System > Battery. Don't forget the Lower Screen Brightness While In Battery Saver option at the bottom of this screen. Dimming the display is one of the most effective ways to save battery life when you need it.
To turn on Battery Saver manually without open Settings, click the battery icon in the notification area and then click the Battery Saver option. You can tell that Battery Saver is on by the green leaf that appears over the battery icon. Click that option again to turn Battery Saver off.
Battery Saver is automatically turned off when you plug in to an external power source.