Hello everyone,

Finalizing my wiring diagram for an off-grid 2019 Ram ProMaster 2500 electrical system and wanted to get some eyes on the logic before I start the physical electrical build. I'm building this primarily with Victron and marine-rated components. Most parts have been purchased besides the two Orion XS units, some fuses, and some wire.

**Specs:**

* **System:** 24V
* **Charging:** Shore, solar, and alternator/starter battery
* **Inverter:** MultiPlus II 3000VA
* **Solar:** (4) 12V 100W panels (wired in 2S2P)
* **Total Capacity:** 600Ah (Split into 400Ah Main bank + 200Ah Essential bank)

**The Dual-Bank Logic (BMS Limitations)** I originally wanted a single 600Ah bank, but I’m using Eco-Worthy 100Ah 24V batteries. Recently learned that their internal BMS dictates a strict maximum of 4 batteries wired in parallel. Because of that hard limit, I had to split the architecture:

* **Main Bank (400Ah):** Wired 4P in a star configuration to positive and negative busbars using equal-length 2/0 cables. This feeds the Lynx Distributor and powers my two DC draws: the MultiPlus-II (slot 1) and the Velit 24V Air Conditioner (isolated with in-line fuses and a Victron BatteryProtect) (slot 2). The MultiPlus then handles the heavy AC appliances: an 1800W induction cooktop, 1400W Our Place air fryer, and 1440W Camplux water heater (\*see load management). 
* On the charging side, the fourth slot on the Lynx acts as the primary input hub. The solar charge controller and the starter Orion XS are first combined at an external fused busbar, sending a single, unified charging cable into slot 4.
* **Essential Bank (200Ah):** The remaining two batteries are wired in parallel. The main bank charges this essential bank via a second Orion XS, which draws its power directly from slot 3 on the Lynx Distributor. This bank powers the Dometic 110U DC fridge, two 24V Govee light strips, the Cerbo GX, and an Orion 24/12 step-down converter which runs a Shurflo 12V water pump (90W, 7.5A max) and a Maxxair MaxxFan Deluxe (60W, 5A max).

\***Load Management** Since a 3000VA inverter can’t handle an induction cooktop, air fryer, and water heater simultaneously, I put the water heater on a physical on-demand toggle switch. It’s a hard forcing function so I can’t accidentally overload the inverter while cooking.

**Wiring & Fusing Choices**

* **Solar:** Wiring the four 12V nominal 100W panels in 2S2P to get the voltage up high enough (\~40V) to wake up the 24V SmartSolar MPPT.
* **Charging Inputs:** The MPPT and the starter Orion XS positives are combined at a heavy-duty busbar with MIDI fuses, then sent via a single cable to the 4th slot on the Lynx.
* **Main Fusing:** 400A Class-T fuse paired with a 450A manual isolation switch on the main 400Ah bank.
* **Grounding:** DC negative, AC breaker box ground, MultiPlus case ground, and all other DC negatives join at a central Earth Busbar, grounded to one bare-metal spot on the chassis.

**Grounding Question:** Since my starter battery is up front and the house bank is 23 feet away in the back, I’m running 2/0 AWG cable down the length of the rig to eliminate voltage drop. To adapt this heavy cable to the Orion XS, I’m routing the 2/0 line into a fused busbar first, to transition down to a short (6inch) 4 AWG run for the final connection. To properly ground the DC-DC charger, do I actually need to run a dedicated 23ft 2/0 negative cable all the way back to my rear busbar, or will grounding the starter at its factory bus and relying on the van's steel chassis work perfectly fine as the return path? Concerned this would create a ground loop?

Does this logic hold up? Are there any glaring bottlenecks or redundancy issues I'm missing with this architecture? Any safety issues I'm overlooking? Thanks in advance.

Dual-bank 24V / 600Ah Victron wiring diagram (DIY ProMaster van build). Split banks due to BMS limits. Sanity check my logic pleaseeee.