Embodiments of the present invention relate to a battery system with internally powered real time clock, the battery system includes a plurality of battery cells connected in series and/or in parallel between a first terminal and a second terminal and a real time clock electrically connected to a first node of the plurality of battery cells, a voltage of a single battery cell of the plurality of battery cells applies to the first node, and the real time clock draws power via the first node in a first operation state and in a second operation state of the battery system.