My older HP laptop occasionally becomes almost unusably slow immediately after I connect the charger. CPU usage rises from around 20% to roughly 98%, OBS recording performance drops from 60 FPS to about 12 FPS, videos buffer even when stored locally, and the Start menu can take several seconds to open. The problem disappears as soon as I unplug the laptop.
The issue first appeared around September 2025. It lasted about a week the first time, but now usually lasts a few minutes and happens every few days. It has occurred just after booting, during recording sessions, and while uploading files. I have tried changing the power settings between power saver and performance modes, but that did not solve it. I have not noticed a clear temperature spike, although the laptop does run hot occasionally.
The charger has no visible damage, and malware scans have not found anything. The battery has also degraded significantly and now lasts only a few hours instead of several days.
The laptop has an 11th Gen Intel Core i3-1125G4, 8 GB of RAM, Intel UHD Graphics, and a 238 GB drive with about 210 GB used. In Task Manager, I have not seen a new program suddenly consume the CPU; the main noticeable change is the Start process using much more CPU when I try to open the Start menu. What could cause charging to trigger this behavior, and what troubleshooting steps should I try before replacing the laptop?
3 Answers
Check Task Manager's Processes and Performance tabs while connecting the charger. Sort by CPU usage and also watch the CPU speed, temperature, and power mode. A power-management, thermal, or charger-detection problem can cause the system to behave differently when plugged in. If the CPU speed is dropping very low, overheating or a faulty power adapter may be involved. Running HP's hardware diagnostics and updating the BIOS, chipset, and power-management drivers would also be worthwhile.
The power profile normally changes when a laptop is plugged in, but it should not make the machine nearly unusable. Since the battery is badly degraded and the problem is tied specifically to AC power, test with a known-good HP-compatible charger that has the correct wattage. Also inspect the charging port and run the manufacturer's battery and adapter tests. A failing battery, adapter, or charging circuit can cause repeated power-state changes and severe performance problems.
A background miner or other malware is possible, but the intermittent, charger-dependent behavior makes a hardware or power-management issue more likely. Keep Resource Monitor or Task Manager open during an episode and check whether CPU time is going to a particular process, Windows interrupts, or system activity. With only 8 GB of memory and more than 85% of the storage occupied, free some disk space and reduce startup programs too, although those limits alone would not normally explain the instant change when plugging in.
Several scans have already come back clean, and the slowdowns are not constant. I will still check system activity and free up storage in case low disk space is making the recording and power changes worse.
I have checked Task Manager, but nothing obvious starts using the CPU besides the Start process becoming very busy when I open it. I will monitor CPU speed and temperatures more closely the next time it happens.