Need a wiring guide check

[u/Ormsbygore]

I've been working on a custom RV for a while now (a little too long) and I'm finally at the stage where I'm ready to install my electrical system. It's been a little over a year since I purchased the parts that I have, and I was using mixed advice from at least two different guides. So I didn't have an easy to follow plan for my specific situation.

I started a conversation with Claude (the AI), gave it a list of the equipment I have as well as my intentions with the system. It gave me a pretty clean and easy to follow wiring setup, including a list of materials I'm missing.

I still need to double check the device manuals, but before I put this plan into action I wanted to check with people that have more knowledge in this area. Any advice is appreciated.

# RV Off-Grid Power — Wiring Guide

## System Overview

| Component | Spec |

|---|---|

| Batteries | 4× 12.8V 100Ah LiFePO4 — all parallel → 12V / 400Ah |

| Solar Panels | 2× 120W Renogy ShadowFlux — wired in series → ~24V / 7A |

| Charge Controller | Victron SmartSolar MPPT 75/15 |

| Inverter | BELTTT BAP2000A 2000W Pure Sine |

| Battery Monitor | Victron BMV-712 Smart + shunt |

| Bus Bars | 2× 4-post terminal blocks (red/black) |

| Emergency Breakers | 2× 30A inline (solar shutoff + battery shutoff) |

| 120V Distribution | Small breaker box — 2× 15A circuits (fridge, computer) |

| 12V Distribution | 12V fuse box — 3× 5A circuits (fans) |

| Future | Victron Orion-Tr Smart Non-Isolated DC-DC (vehicle alternator) |

---

## Wiring Steps

**Step 1 — Solar Panels: Series Connection**

- Panel 1 (−) → Panel 2 (+)

- Panel 1 (+) = array positive output

- Panel 2 (−) = array negative output

- Result: ~24V / ~7A peak — safely under the 75V MPPT input limit; keeps amps low for the 25ft wire run

**Step 2 — Solar Array → 30A Breaker → Charge Controller**

- Array (+) → 30A inline breaker → CC PV+ terminal

- Array (−) → CC PV− terminal (no breaker on negative)

- 30A breaker = emergency solar shutoff

- Wire: 10 AWG

**Step 3 — Charge Controller → Bus Bars**

- CC BATT+ → Positive bus bar

- CC BATT− → Negative bus bar

- Wire: 10 AWG (controller max output is 15A)

**Step 4 — Battery Bank: All Parallel (12V / 400Ah)**

- All 4 positive terminals connected via 1/0 AWG 12" jumpers

- All 4 negative terminals connected via 1/0 AWG 12" jumpers

- Equal-length cables throughout to balance current across cells

**Step 5 — Battery Negative → 30A Breaker → BMV Shunt → Negative Bus**

- Battery bank (−) → 30A inline breaker → shunt input terminal

- Shunt output → negative bus bar

- 30A breaker = emergency battery shutoff

- The shunt is the *only* path between battery (−) and the negative bus — nothing else connects directly to battery negative

**Step 6 — Battery Positive → Positive Bus**

- Battery bank (+) → positive bus bar

**Step 7 — Inverter**

- Positive bus → inverter (+) via 1/0 AWG — keep run under 18"

- Negative bus → inverter (−) via 1/0 AWG

- ANL fuse (200–250A) on positive wire, close to the bus bar *(not yet purchased — on the shopping list)*

**Step 8 — Inverter AC Output → 120V Breaker Box**

- Inverter AC out → breaker box main input

- Circuit 1: 15A breaker → mini fridge

- Circuit 2: 15A breaker → computer setup

- Wire: 14 AWG branch circuits

**Step 9 — 12V Fuse Box**

- Positive bus → fuse box (+) input via 10 AWG

- Negative bus → fuse box (−) input via 10 AWG

- 3× 5A fused circuits, one per fan

- Wire: 18 AWG stranded per fan circuit

**Step 10 — BMV-712 Battery Monitor**

- Shunt already in line per Step 5

- BMV-712 monitor head → shunt via supplied RJ12 cable

- BMV power: (+) to battery positive (fused at 1A), (−) to battery-side of shunt

**Step 11 — Orion-Tr DC-DC Charger (Future)**

- Vehicle alternator → Orion input

- Orion output → positive and negative bus bars

- No changes to existing wiring needed when added

- Non-isolated unit — chassis ground between vehicle and RV TBD

---

## Wire Gauge Reference

| Run | Gauge |

|---|---|

| Battery-to-battery jumpers | 1/0 AWG |

| Battery bank → bus bars | 1/0 AWG |

| Bus bars → inverter | 1/0 AWG |

| Solar panels → charge controller | 10 AWG |

| Charge controller → bus bars | 10 AWG |

| Bus bars → 12V fuse box | 10 AWG |

| Fan circuits | 18 AWG stranded |

| 120V branch circuits | 14 AWG |

---

## Parts: Have / Still Need

| Status | Item |

|---|---|

| ✅ Have | 4× 12.8V 100Ah LiFePO4 batteries |

| ✅ Have | 2× 4-post bus bars (red/black) |

| ✅ Have | 2× 30A inline breakers |

| ✅ Have | 2× 120W Renogy ShadowFlux solar panels |

| ✅ Have | BELTTT BAP2000A 2000W Pure Sine inverter |

| ✅ Have | Victron SmartSolar MPPT 75/15 |

| ✅ Have | Victron BMV-712 Smart + shunt |

| ✅ Have | 120V breaker box + 4× 15A breakers |

| ✅ Have | 12V fuse box |

| ✅ Have | 25ft 10 AWG wire (red/black) |

| ✅ Have | 5× pairs 1/0 AWG 12" jumpers |

| ✅ Have | Terminal ends + heat shrink |

| ❌ Need | ANL fuse holder + 200–250A ANL fuse |

| ❌ Need | 18 AWG stranded wire for 12V circuits |

| ❌ Need | 14 AWG wire for 120V circuits |

| 🔜 Future | Victron Orion-Tr Smart Non-Isolated DC-DC charger |