I'd just charge with with mains AC.
I can buy mains power at $0.06 to $0.16 during daylight hours as I get wholesale realtime rates with my provider. As my panels are also mains connected I could charge the batteries from wall socket AC provided by the solar as well. I get that that's a little...
Tried searching for previous discussion on this but perhaps I'm using the wrong search terms.
Recently I purchased a portable power station for my wife's business as she is a musician and often needs to run her PA with no mains power available. I was really impressed by the quality and price...
Sorry I should have been clearer im considering stand alone batteries with their own inverters as a "portable power station". So a centralised inverter wouldn't be necessary.