You can use ThrottleStop[1] to disable PROCHOT on non-standard battery. I encountered similar issue with throttling on my Dell Precision laptop when I was charging it via 60 W USB-C charger instead of proprietary barrel-type 130 W plug. The system triggered a warning about low power charger and initiated aggressive cpu frequency scaling. By using ThrottleStop, I was able to use type-c 60W charger on lightweight tasks (such as web browsing, older games) just fine.
[1]: https://www.techpowerup.com/download/techpowerup-throttlesto...
Dell likes to pull this stunt on other devices too. Like their 1L desktops in the OptiPlex line that I managed for many years. Even though we were using genuine Dell power adapters, if they became slightly unplugged but remained powered, they would enable PROCHOT.
This was fine until the machines randomly started setting PROCHOT on genuine power adapters that were fully plugged in. Eventually I just deployed a configuration with PDQ to all the machines that ran ThrottleStop in the background with a configuration that disabled PROCHOT on login.
Unfortunately, I couldn't get it to consistently disable PROCHOT pre-login, so students and teachers in my labs would consistently wait 3-4 minutes while the machines chugged along at 700 MHz as they prepared their accounts.
>You can use ThrottleStop[1] to disable PROCHOT
Dell disables that tinkering on some models of XPS in BIOS/EC so ThrottleStop won't to jack.
On my non Thinkpad lenovo yoga (Whiskey Lake) disabling bd_prochot leads to crash.