today my acer nitro 5 will not power on with mains power. the battery is 100% but, when i take it off charge it turns off.
ive done some research but, wanted to know what u guys' idea are.

This happens to batteries when u leave it plugged in when its already at full. going to need to replace it, and try not to leave it plugged in all the time.

from a quick search its says it not a problem to leave the laptop always charging

UPDATE: I recalibrated the battery and all is working again

"You can fix a laptop that only works when plugged in by disabling and re-enabling the ACPI-Compliant Control Method Battery and restoring the default power schemes in your power profiles within Windows 10. These methods should work for HP, Dell, Lenovo, Acer, and other laptops that won't turn on unless plugged in."

Maybe?

I still think leaving your device plugged in wears out your battery faster.