Re: Can I stack inverters with different wattage?
Stacked inverters must be units designed for that application; you can't tie together any two inverters and get anything other than smoke, sparks, and fire. So two Outback 3524's, yes. One Samlex and one Magnum no. Likewise they should be of the same Wattage. In theory two different Watt but compatible units could be connected, but when the load goes up the smaller unit will be over-taxed in comparison to the larger one. Stack-compatible inverters synchronize by having one "Master" inverter from which the "Slave" inverters take their cue for frequency synchronization and power output. Mis-matched units would probably result in confused synch info. I don't know exactly because I don't build the things and I'm not going to try any such experiment!
Don't know if I'm explaining this well.
Grid-tie inverters function in a similar fashion, viewing the grid as a "stacked inverter".
There are experts in this field here who can give you quite a detailed explanation, if you wish.
Four 175 Watt panels, OB MX60, 232 Amp hrs, OB 3524, Honda eu2000.
Ohm's Law: Amps = Volts / Ohms
Power Formula: Watts = Volts * Amps