The left side dash display is controlled by the shuttle control on the left side of the steering wheel. Moving left or right switches between groups of displays, and moving up or down switches between displays within a group. I'm not adept with this, but the battery temp display is in the same group as the compass /satellite radio preset / digital speed display option. When you see that one, move 'down' (I think) to get to the battery temp bar /capacity display. Someone correct me if I have this wrong, because I leave it on the battery temp in warm weather, and the aforementioned compass/speed/preset display in cool weather, rarely switching. It remembers the display choice when the car is off.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.