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Solar Assisted Battery Backup System

This DIY system consists of a Schneider XW6848 inverter, Schneider 60-150 charge controller, 12 AGM batteries, and 3 SolarWorld 310XL modules on a mobile frame.  This permits me to aim it at the sun during the winter and get more power during an outage.

The battery bank’s specification is 48v @ 300aH (14.4kWh), and consists of 12 DEKA Solar AGM batteries wired in parallel/series.  Usable power at 80% depth of discharge is 11.5kWh.

The XW6848 hybrid inverter is rated at 6.8kW continuous (12kW surge) and powers all the computers and IT equipment, two refrigerators, a chest freezer, and a bunch of receptacles.  When the grid is operational, it cancels out grid-side draw from the backed up load.  When the power fails, it islands itself and keeps those critical loads running without a hiccup.

It’s basically a large solar assisted UPS.  If solar gain is too low, I can fire up the 8kW portable generator to recharge the batteries.  The main benefits here are that there is no interruption of power during an outage, the generator doesn’t need to run 24/7, and the solar panels help reduce gas usage.