Title: HP Pavilion Gaming 15-ec2xxx (Ryzen 7 5800H) CPU stuck at 0.39 GHz on battery, but works normally when plugged in
Hi everyone,
I'm facing a strange CPU throttling issue with my HP Pavilion Gaming laptop and would appreciate help diagnosing the cause.
Laptop specifications:
Model: HP Pavilion Gaming Laptop 15-ec2xxx
Product number: 552W3PA#ACJ
CPU: AMD Ryzen 7 5800H
RAM: 16 GB
BIOS version: F.31 (dated December 10, 2025)
OS: Windows 11 Home Single Language
The problem:
When the laptop is connected to the charger, the CPU works normally and reaches around 3.75 GHz under heavy load.
However, when I disconnect the charger and run the same CPU stress test on battery, the CPU speed drops to approximately 0.39 GHz, even when CPU utilization reaches 90–100%.
Restarting the laptop can temporarily restore normal performance, but the problem returns under certain conditions.
What I've checked so far:
HP PC Hardware Diagnostics: Fast CPU stress test passed.
HP battery test: Passed.
Battery report: Design capacity 36,394 mWh; full-charge capacity 36,394 mWh.
Battery manufacturer reported by Windows: HP.
BIOS version: F.31.
Windows power plan: Balanced.
Maximum processor state: 100% on battery and plugged in.
Minimum processor state: 5% on battery and 80% plugged in.
Adaptive Battery Optimizer: Enabled.
The BIOS detects the primary battery.
I have not yet confirmed whether the battery itself, its controller, the embedded controller (EC), or the motherboard's power-management circuitry is responsible.
My questions:
Has anyone experienced the Ryzen 7 5800H being locked at 0.39 GHz only on battery?
Could a replacement battery or battery communication issue trigger this behaviour?
Could the embedded controller or a power-limit signal be forcing the CPU to throttle?
What diagnostic test would help identify the actual cause before replacing any parts?
I would prefer to diagnose the issue properly rather than buy another battery or replace hardware unnecessarily.
Any suggestions or similar experiences would be appreciated. Thank you!