Simple solution for home battery backup and existing solar install?

[gvl]

I have a 9kW array with SolarEdge inverter that was put in service about 10 years ago. Are there off-the-shelf solutions that allow to charge a battery from the inverter (AC coupling I think is the term) in case of a power outage? I realize I will need to install a transfer switch between the inverter and the main panel/grid to be able to charge the battery.

Ideally I envision a poor-man's setup that consists of a backup power inlet feeding the main panel and a mechanical interlock installed on the main breaker. In case of an outage I flip the main breaker OFF/connect the battery to the backup power inlet/turn on the battery and flip the backup power breaker ON, this fools the solar inverter into thinking the grid is connected, it starts to produce power that powers the home and charges the battery. The battery naturally buffers any reductions in solar output.

What are my options?

[organic farmer]

In my system, the battery bank is 48vdc [the amperage is not material to this discussion]. I found a 52 volt power supply online, it may only put out 20 amps but that is enough for a slow charge.

I checked the fluid levels in all batteries, Then started charging. Every day that is was charging I checked the fluid levels again. Eventually after a week the battery bank was fully charged once again.