I have 675w solar, 1000 AH battery and 2000w inverter all at 12 volts. Works great. Large battery is not a big deal but a larger inverter and solar starts to be impractical. With 1500 watts solar may need 2 or more controllers at 12 volt. Inverter maybe 3000w would be 12v maximum and even that would be better at 24v.
Equipment at 36v is fairly thin. I would avoid this. Equipment at 48v is probably overkill unless powering a 50 amp RV with two A/C and probably 2kW+ solar.
Charging from the vehicle needs a step up converter, powering existing 12v items needs a step down converter. Step up for charging may not matter much with 1500w solar. Step down need enough power to run the slide, emergency braking, and leveling system if equipped. Some of these 12v items can be high amp draws and exceed the rating of most equipment.
Post a list of primary equipment for evaluation before purchasing.