Can We Use Battery Saver All The Time. See screenshot below 3 Select Never 10 20 default 30 40 50 or Always for what you want in the Turn battery saver on automatically at drop menu on the right side. As you can read here Microsoft advises against turning on the battery saver all the time.

Turn off Always on Display. Battery Lifespan Saver - Battery Lifespan Saver is a feature designed to help protect your battery from the cumulative negative effects of consistent and recurrent use at high temperatures or high states of charge. Power saving mode will limit certain things on your device such as background network usage and syncing.
It stops charging as soon as it hits 100 and directs the power to your laptop.
But you can control this and choose what exactly battery saver does. This will disable. Better yet Battery Saver is automatically enabled when you reach 20 battery life by default and you can adjust this threshold. Power saving mode will limit certain things on your device such as background network usage and syncing.

