A failing battery or battery calibration problem. CMOS Checksum is invalid (Error 502)

[debangaroy_12]

My laptop exhibits two critical issues:

Rapid Battery Discharge and Shutdown :
After being fully charged and the charging plug is removed, the laptop operates on battery power for only a short duration, approximately 10 to 20 minutes. During this short period of unplugged use, the battery indicator typically shows a discharge from 100% down to around 50% to 40%. Following this rapid discharge, the laptop automatically shuts down without any warning, indicating a critical loss of power despite the battery indicator suggesting a remaining charge. This issue occurs every time the laptop is unplugged after a full charge.

" CMOS Checksum is Invalid " Warning:
Upon starting the laptop, the following error message is displayed:
"The CMOS checksum is invalid, The CMOS will reset to the default configuration, and the computer will restart. Afterwards, please check the BIOS setup options to see if they change.
CMOS Reset (502)
ENTER- Restart the computer
For more information, please visit the website or scan the QR code

http://www.hp.com/go/500bioserror”

These two issues are occurring concurrently and impacting the usability of the laptop. It's unclear at this time if they are related or independent problems.

[VikramTheGreat]

Hi @debangaroy_12,

Welcome to the HP Support Community.
 

Thank you for posting your query. I will be glad to help you.

We understand that your HP 15-gw0000 Laptop PC is experiencing two critical issues: rapid battery discharge with unexpected shutdown, and a CMOS checksum error (502) at startup. We sincerely apologize for the inconvenience this has caused and are here to assist you in resolving both concerns.

Rapid Battery Discharge and Unexpected Shutdown

This issue may be related to battery health, BIOS misconfiguration, or hardware faults. Please follow the steps below to diagnose and address the problem:

Step 1: Perform a Battery Check Using HP Hardware Diagnostics

1. Shut down your laptop completely.
2. Press the power button, and immediately start tapping the Esc key repeatedly until the Startup Menu appears.
3. Press F2 to open HP PC Hardware Diagnostics.
4. Select Component Tests > Power > Battery Test.
5. Follow the on-screen instructions to complete the battery diagnostic.

• If the battery test fails, please note the Failure ID and contact HP Support for a battery replacement if under warranty.
• If the test passes, proceed to the next steps.

Step 2: Calibrate the Battery

Battery calibration helps correct inaccurate charge level reporting:

1. Charge the laptop to 100%.
2. Disconnect the charger and use the laptop until it automatically shuts down due to low battery.
3. Charge it again to 100% without interruption.

This can help improve battery level accuracy, though it may not resolve a physical battery fault.

Step 3: Update the BIOS

An outdated BIOS can lead to power management issues.

1. Visit: HP 15-gw0000 Laptop PC series Software and Driver Details
2. Download the latest BIOS update F.41 Rev.A available for your model.
3. Carefully follow the instructions to install the update.

I hope this helps.

Take care and have a good day.

Please click “Accepted Solution” if you feel my post solved your issue, as it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping!

VikramTheGreat

HP Support