I find myself on vacation right now and brought with me my trusted laptop like i always do that can run some light games no problem including TM. When i play Trackmania2020 something odd happens;
When i play while the laptop is charging (aka the laptop is connected to the brick which is connected to an outlet), my FPS reach the target lock of 150 (monitor is 144hz so it's fine), both in the menus AND while playing on a track.

BUT

When my laptop is not charging (aka only using battery power) the FPS while in the menus is the same as mentioned before, yet as soon as i load into a map they DROP AND LOCK at 30.
Before anything i already checked all the battery saving options there are and even when turned full tork on just battery power, but the issue remains.
My laptop is a Lenovo Legion Y540-15IRH - Type 81SX

Does anyone have any clue why this happens and how to fix this??
Thanks!