Convoy S2+ low voltage warning at 2.45v

After hours of off and on over few days, it started flashing at low mode.
Soon after that, it started flashing at very low output, probably sub lumen.
This light doesn’t even have that mode.
It only has 5, 40 and 100%.
I pulled the battery out and tested at 2.45v.
Battery is Samsung 26f.
Is this normal?