change the refresh rate to 60hz on Razer blade 15 2018 advance and get more battery time

HI! I have razer blade 15 2018 advance 144hz, and unfortunately i cannot lower the refresh rate to 60hz in order to save battery. Is there a way to reduce the refresh rate to 60hz? I tried on razer synapse, Nvidia control panel, Intel control panel, Windows settings. Basically everywhere i've looked i wasn't able to change the refresh rate. Currently my battery last around 2.5-3.5 hours on browsing, While the battery settings are on "Battery saver", Keyboard leds off and screen on medium brightness. I've read online about reducing cpu & gpu performances but i haven't found good tutorial in the topic. So, how can i change the refresh rate from 144hz to 60hz, even tough i tried everywhere i can to change the settings. And second, how i can get more battery time. Thanks