Can I add a battery to a Sungrow SG5K-D?
Yes, but not through an evidenced native battery port on the SG5K-D. The conservative retrofit path is to keep the solar inverter and add a separate AC-coupled battery system, or replace the inverter with a hybrid if the desired battery/backup architecture requires it.
What BecSpec can prove
Sungrow identifies the SG5K-D as a widely installed Australian PV inverter; Sungrow says more than 100,000 SG5K-D units were installed in Australia. The available OEM evidence does not establish it as a battery hybrid.
Backup
Do not infer backup from the existing inverter. Backup depends on the new storage inverter/controller, transfer arrangement and site wiring.
What to verify
Exact nameplate model, phase, existing export-control/metering configuration, the chosen AC battery architecture, backup circuits and current scheme/network requirements.