Need help designing off-grid system

[Bigbus]

Ok so forget the circuit panel. What about grounding the battery bank and inverter. Do I need to ground both? A wire from a negative battery terminal to the chassis and a wire from the inverter's grounding post to the chassis?

[thastinger]

Ok so forget the circuit panel. What about grounding the battery bank and inverter. Do I need to ground both? A wire from a negative battery terminal to the chassis and a wire from the inverter's grounding post to the chassis?

Doesn't sound like you're pulling a permit to do this. It is hard to get electrical answers here.
You can download a copy of the NEC for free, there is now a specific section of PV systems.
Battery ground isn't ground, don't ground your equipment to that, you need Earth ground which typically takes at least 2 8 foot long copper rods driven into the Earth to get the required Ohms to ground reading. NEC has a grounding and bonding section, keep in ind that the NEC is the minimum, you can always do more.
NEC also discusses your outlet questions with regard to one GFI outlet protecting X number of down-stream outlets.

[PNW_Steve]

Doesn't sound like you're pulling a permit to do this. It is hard to get electrical answers here.
You can download a copy of the NEC for free, there is now a specific section of PV systems.
Battery ground isn't ground, don't ground your equipment to that, you need Earth ground which typically takes at least 2 8 foot long copper rods.

permits and ground rods may present some challenges in this circumstance......