Phenquestions
There appears to be no single solution for 'Alert, System battery voltage is low' error message which you may see during boot. It flashes on your computer screen, prompting a user to strike the F1 key to continue, F2 to run the setup utility or F5 to run onboard diagnostics. Let us find the cause of this issue and see how to fix it.
Alert, System battery voltage is low
Primarily, there are two reasons which cause the battery voltage low alert to pop up. These are,
- The sensing circuit on the motherboard
- The Battery
If your Windows computer displays a message Alert, System battery voltage is low during boot, here are a few things you need to take a look at.
Replace CMOS Battery
The sensing circuit on the motherboard has a minimum voltage threshold of 2.7V to 2.9V (this figure varies depending on the age of board). Anything below the specified value will invariably give you low battery voltage alert, every time you power on your computer.
In most cases (99%), the problem is easily resolved by replacing the CMOS coin cell battery. One should ensure the battery replaced is a 3-V CR2032 lithium battery. Start your system. In order to get the motherboard to recognize this new battery without any hassles, you have to power cycle the computer three times. Replacing the battery and restarting your system constitutes the first cycle.
During the second cycle, when you still see the error, restart your PC and go to the BIOS setting. There, go to 'Maintenance', expand its menu and select 'Defaults' from the list of options displayed. Save the setting and exit,
Set up Date and Time in BIOS
If the wrong date and time have set, you may need to change your time zone. For this, right-click on the date and time in the Windows Notification Area seen at the bottom right corner of the screen and select Adjust date/time. At this point, make sure that the Time Zone set is correct.
To manually change the time, turn off the Set time automatically option and then click the Change button. Set the correct time.
Reset/Update CMOS/BIOS
It may happen that the information stored in the BIOS as ESCD (Extended System Configuration Data) can get corrupt due to reasons, unknown. Under such circumstances, it becomes necessary to reset the BIOS or CMOS (Complementary metal-oxide-semiconductor) to “Factory Defaults”, or in other circumstances, clear the NVRAM (Non-Volatile Random Access Memory). Here's how to do it.
- Turn off the computer and disconnect the power cable from its electrical outlet. Now, it's safe to remove the computer cover.
- Uncover and locate the 2-pin password connector (PSWD) on the system board.
- Disassemble the 2-pin jumper plug.
- Now, find the 2-pin CMOS jumper (RTCRST) on the system board and move the 2-pin jumper plug from the password jumper to pins into the CMOS jumper.
- When done, plug in the AC power to the system and pause for a few seconds for the CMOS to clear.
- Move the 2-pin jumper plug back to the password jumper and replace the computer cover.
- Finally, connect your computer and devices to electrical outlets, and turn them on.
Please note that you run a significant risk of permanently damaging your computer if you resort to this method. So, if you fail to access your BIOS, it is advisable to take the computer to an expert and seek his help instead of doing it yourself. For more options, see this.
Removing surge suppressors
Some computer manufacturers also claim the problem is caused by some surge suppressors. As such, you can eliminate this problem by simply removing the surge suppressor and plugging the PC directly into the wall outlet.
If you find these suggestions a bit difficult to carry out, perhaps you want to take your PC to a technician.
