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Running Microsoft Windows 7 Home Premium on a HP Laptop. The system tray power meter never shows the time remaining in the system tray. Only really ever show a percentage remaining number as pictured.

battery meter

battery meter full

The windows help documentation on the "battery meter" seems to indicate that it should display a time remaining indicator, is this accurate?

How accurate is the battery meter?

The accuracy of what the battery meter reports—what percentage of a full charge remains and how long you can use your laptop before you must plug it in—depends on several factors. Most of these factors fall into the following two categories:

What you use the laptop for. Because some activities drain the battery faster than others (for example, watching a DVD consumes more power than reading and writing e‑mail), alternating between activities that have significantly different power requirements changes the rate at which your laptop uses battery power. This can vary the estimate of how much battery charge remains.

Battery hardware and sensor circuitry. Newer, "smart" batteries are equipped with circuitry that calculates the measurements of charge remaining and reports the information to the battery meter. Older batteries use less sophisticated circuitry and might be less accurate.

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Do you get a time estimate when you bring up the Windows Mobility Center with [Win]+[X]? If not, then I'm pretty sure that this is a hardware dependent feature. – iglvzx Mar 26 '12 at 3:36
@iglvzx Yes tried the Windows Mobility Center, no remaining estimate must be a hardware cheapness factor. – MrDaniel Mar 27 '12 at 11:58
up vote 4 down vote accepted

Finding the time remaining on your battery charge is actually a function of the hardware, not Windows. Windows queries the hardware for the time, via the ACPI. If this data is not provided, then Windows will not report a time. This is probably because the hardware would be the best place to determine such information, as it has direct knowledge of the battery info and amount of power draw.

This may be typical of HP laptops. My HP Pavilion tx2500z also did not support reporting this data. I found that it actually didn't have much when it comes to ACPI (I discovered this when attempting to install Linux and finding myself having to call the kernel with custom options).

Windows 7 does not attempt to estimate a value for time remaining if it cannot ask for it. However, the widget suggested by @user124759 does have this capability. It probably isn't as accurate, but is a worthy replacement.

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it could be the computer has not yet figured out the battery specifications. my new Surface Pro 3 which is a premium machine made by Microsoft doesn't show the time. I'm hoping after a time it will though – Simon Aug 5 '14 at 7:17

This is due to Connected Standby.

A simple change of a registry key and a system restart exposes all the legacy functionality and will return the time remaining:

HKLM\System\CurrentControlSet\Control\Power\CsEnabled (1->0)

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Simple solution:

I've been using this widget for a long time and it does not need to go through windows to detect time remaining (it "auto-detects")

To install you may have to right click on your desktop and open "gadgets"

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I used this widget on my old HP Pavilion tx2500z laptop for the couple years I had it, since I had the same issue as the OP. It's very handy. Wish there were more, similar options available. – Ben Richards Mar 26 '12 at 18:18
It's not seeing my time remaining on this MSI U135 DX laptop I have. – barlop Jun 2 '13 at 21:17
batterybar worked more quickly, though im' not sure on accuracy. and soon, perhaps after a while of haing the power out, I noticed windows started reporting how much was remaining. but batterybar calculated it itself as soon as I started batterybar. – barlop Jun 2 '13 at 22:17

I came across a handy free app called battery optimizer by reviversoft, I ran it on win8 preview edition and defender seen it as a hacktool.exe but it shows time left and other tweaks, probably work in win7.

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Sorry can't test it on it, got rid of that HP egg timer... – MrDaniel Aug 15 '12 at 17:55

protected by DavidPostill Nov 1 '15 at 17:31

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