just after going down the elevator is one sitting in the room on the right next to what appears to be some kind of fushion generator. There is another in Boston Mayoral Shelter. There is another one in lexington sitting under a weapons workbench on the right side of lexington (right of the monumental statue that sits near the middle before the bridge with the raider decked out in power armor)

There is one in hardware town behind the main counter sitting under a weapons workbench there should be a couple to a few floating around in there (but these don't respawn if you got them all) If you didn't pick fort Hagen completely clean. There is another battery in the Croup Manor basement under a weapons workbench. There is another battery inside the cambridge diner sitting underneath a yellow laundry sink There is a makeshift battery on the robotics disposal grounds sitting in the bunker near a weapons workbench. not all of them are super reliable when you've picked them clean. or at least the atomics galleria gym doesn't. Right now, I'm still in vanilla game without mods, but with the mod that respawns all cells immediately. but, makeshift batteries is primarily what I look for.

not even wiki pages have any locations for where junk should respawn. I was actually surprised that no one has really done this. I made my own lists where things respawn. I'm the most unconventional player in the Fallout Universe probably, and noticed that since all of the environmental pieces respawn. I'm not sure if you still want this information since you made this a year ago.

Fallout 4 where to find lead