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‎08-19-2025 03:57 AM

HP Recommended
Operating System: Microsoft Windows 10 (64-bit)

I am using an HP EliteBook 820 G3. My laptop does not power on unless the charger is connected, even when the battery is fully charged (100%).

When I turn it on, I get the following POST error message:
"Real-Time Clock Power Loss (005)" and "The system time is invalid. This may be a result of a loss in battery power."

After this, the laptop only boots if the charger is plugged in. If I remove the charger, the laptop immediately shuts down.

I already checked the Windows battery report. The design capacity and full charge capacity both show 12,449 mWh, which seems very low compared to normal laptop batteries.

I think either the main battery is degraded or the CMOS/RTC battery is dead. Could you please confirm if replacing the CMOS battery and/or the main battery (SN03XL, 44Wh) will solve the problem?

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