Epson 4SLC2-50 - Manual (Page 53)

7. Slide the battery cover back into place making sure the tabs on
the cover fit into the slots on the computer’s cover. Press the
cover from the back side until it snaps closed.
Note
When you replace the battery pack, make sure the new
battery is fully charged; otherwise you’ll need to recharge it
before you can use it.
8. Turn the computer right side up.
3-4 Powering the Computer