1. This really isn't a project for the faint of heart

2. To install four PVX-2580s in the four-tier configuration, the PSR is assembled around the batteries. To remove the batteries, the PSR must be disassembled

3. You cannot assemble/disassemble a four-tier configuration below a PS2.
4. You cannot assemble/disassemble a four-tier configuration in the corner of a room.
5. You cannot assemble/disassemble a four-tier configuration and use the top KO on the PSR.
6. You'll need to install 1"x1" or 2"x2" strips on the plywood shelves to prevent the batteries from sliding. Otherwise, a battery terminal could come in contact with a shelf bracket.
7. It would be a good idea to put a piece of plywood in the top panel of the PSR to prevent an accidental short directly across the terminals of the top battery.
8. The PSR-SZ4 seismic kit is highly recommended. The electrical inspector will probably require some kind of support that will prevent the PSR from tipping over.
9. Concorde PVX-2120 batteries are a little narrower than the PVX-2580 and could be installed in the PSR by lowering them through the shelf brackets. This would be a little less effort than assembling the PSR around the batteries. Still, this only works if there is nothing above the PSR and the top KO isn't used.