ecactus WH-SPHA3.6H-5.12kWh User Manual page 19

Step 7 ：Install the second battery box
Put the second battery box smoothly on the top of the first battery box,
and be careful not to hit the Back plate.
Step 8 ： drilling holes
Put the pre-installed battery box in a specified position, so that it is
close to the fixture, mark it according to the hole position on the
back plate, then rotate the back plate at an angle (or take the
backboard away), and drill holes at the fixture with Ø10mm.
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