Problem Number 1
Recently I realized that my laptop's low battery notification doesn't appear at all, so I thought I had accidentally toggled it off.

Went to Google to search for help, then I went into the specific part of Power Options to toggle on my low battery notification. However, I saw that my low battery notification has already been toggled on. So I thought, probably I reset the defaults, it might help.

Today, the same thing happened again. There was no low battery notification and my laptop went into hibernate mode due to low power. Restart my laptop and went to Power Options again. I still see the low battery notification as "on"

How come this is happening ?

Problem Number 2
The battery icon at my tray states 50% (somewhere there) available, but yet my laptop auto goes into sleep mode, and when I switch on my charger and load my laptop and check, the battery icon shows 5% (can't remember, but it is some % below 8%) available (plugged in, charging)

How come this happen ?



My laptop is Acer Aspire on Vista

I am wondering if the problem might actually be in the battery itself or the power adapter or cord. I had a very similar problem and it turned out that after just over a year of use, it was my power adapter. Fortunately I have an extended warranty with HP which doesn't include the battery, but does include the adapter and the cord, so it was covered. But it was a real mystery and we couldn't figure it out --- until the adapter actually died.

This worked perfectly for me when I had the same problem:


Power management software in Windows Vista

Understanding battery charging issues
If the notebook battery is not charging or the notebook does not indicate that the battery is charging, the most likely scenario is that the battery itself is operating correctly, but its power management software may have become corrupt. In order to correct the problem, you will need to uninstall and reinstall the power management software by using the Device Manager. This document will explain how to uninstall and reinstall the ACPI Battery listings in Windows Vista, as well as how to obtain and install updated BIOS files, if needed to correct other battery issues.
Uninstalling and reinstalling power management software in Windows Vista
In order to correct problems with the battery's power management software, follow the steps below.
1. Click Start and type device in the search field, then select Device Manager .
2. Expand the Batteries category.
3. Under the Batteries category, right-click the Microsoft ACPI Compliant Control Method Battery listing, and select Uninstall .
WARNING: Do not remove the Microsoft AC Adapter driver or any other ACPI compliant driver.
4. On the Device Manager taskbar, click Scan for hardware changes .
Alternately, select Action > Scan for hardware changes .
Windows will scan your computer for hardware that doesn't have drivers installed, and will install the drivers needed to manage your battery's power. Restart your computer. The notebook should now indicate that the battery is charging.