Category: 🔌 Electrical System

All wiring, components, diagrams, and research.

Reference: EcoFlow Delta Pro Transfer Switch Installation for Boondocking

Reference: EcoFlow Delta Pro Transfer Switch Installation for Boondocking

This post documents key takeaways from the video
“Best EcoFlow Delta Pro Setup for Boondocking – Install a Transfer Switch!”.
The creator demonstrates how to integrate an EcoFlow Delta Pro into an RV electrical system using an
automatic transfer switch (ATS), allowing the power station to safely power all onboard circuits while remaining protected inside a storage compartment.

This installation method is relevant to my electrical planning, especially as I evaluate the EcoFlow DELTA Pro 3, the Smart Generator 4000, and a 50‑amp shore power inlet for the cargo trailer conversion.

Overview of the Setup

The video shows how the installer wires an ATS into the RV’s existing shore‑power line so the EcoFlow Delta Pro can power the entire RV without running an external cord. The Delta Pro remains inside a storage compartment, protected from weather and theft. The ATS automatically switches between:

  • Shore power
  • EcoFlow Delta Pro
  • Generator input

This allows all interior outlets and circuits to remain live regardless of the power source. The EcoFlow can also recharge from shore power through the same wiring path.

Key Details from the Installation

  • Shore power line is cut and routed into the transfer switch, then back out to the RV’s breaker panel.
  • EcoFlow Delta Pro output is connected to the second input of the ATS.
  • Generator plug is connected to the third input.
  • The Delta Pro remains inside a storage compartment, protected from weather and theft.
  • The system allows the RV to recharge the Delta Pro from shore power without moving the unit.

Safety Considerations Mentioned

Several comments and responses highlight important safety notes:

  • Ventilation: The storage compartment in the video has ~15 sq in of airflow, preventing overheating. The Delta Pro’s BMS will throttle or shut down if temperatures rise too high.
  • Aluminum-to-copper wiring: When joining dissimilar metals, an anti‑oxidant compound should be used to prevent oxidation and fire risk.
  • Breaker management: Some RVs require turning off the onboard battery charger to avoid unnecessary load on the power station.

Why This Setup Is Useful for My Build

This installation method aligns well with my electrical system goals:

  • Keep the EcoFlow unit inside the trailer for protection.
  • Use a transfer switch to safely manage shore, generator, and battery power.
  • Allow the EcoFlow to power all circuits without external cords.
  • Enable automatic charging from shore power.
  • Maintain a clean, modular, serviceable electrical system.

This video serves as a practical reference for integrating the EcoFlow ecosystem into the cargo trailer conversion, especially as I evaluate the DELTA Pro 3, the Smart Generator 4000, and a 50‑amp shore power inlet.

Notes for Future Planning

  • Determine ATS size and compatibility for a 50‑amp shore power inlet.
  • Evaluate ventilation requirements for the EcoFlow storage compartment.

Marine Grade DC Wiring Under Consideration

Marine Grade DC Wiring Under Consideration

For the 12V DC side of this cargo trailer conversion, I am strongly leaning toward using
marine grade wiring rather than standard automotive or household wire.
Because this build will be mobile and exposed to varying temperatures, humidity, and potential condensation,
moisture resistance and corrosion resistance are important factors in the wiring choice.

One specific product I am considering is:


12 Gauge Wire 3 Core Conductor Triplex Twin and Earth Marine Grade 12AWG Electrical Cable – SAKAKI

Product Overview

This cable is a 12 AWG, 3-core, flat triplex “twin and earth” marine grade wire designed for low-voltage DC applications.
It is intended for use in boats, automotive environments, and other mobile installations where vibration, moisture, and corrosion are concerns.

  • Type: Flat Triplex Twin and Earth Marine Grade Cable
  • Gauge: 12 AWG (12/3 wire – three conductors)
  • Conductors: Stranded, tinned copper
  • Insulation: PVC insulated
  • Voltage Rating: 300V (suitable for 5V, 12V, 24V up to 300V)
  • Waterproof Level: IP68
  • Working Temperature Range: -68°F to 176°F
  • Flame Retardant Grade: VW-1
  • Intended Use: Marine, automotive, and other mobile low-voltage applications

Why Marine Grade Wiring Is Being Considered

The cargo trailer conversion will experience vibration, temperature swings, and potential moisture from condensation and outdoor conditions.
Marine grade wiring offers several advantages in this environment:

  • Tinned copper conductors: More resistant to corrosion than bare copper, especially in humid conditions.
  • Stranded and flexible: Better suited for vibration and movement than solid conductors.
  • IP68 waterproof rating: Provides a high level of protection against moisture ingress.
  • Wide temperature range: Suitable for both hot and cold operating conditions inside a trailer.
  • Flame retardant insulation: Added safety in an enclosed space.

Potential Uses in the Build

If selected, this 12 AWG 3-core marine grade cable could be used for:

  • 12V DC branch circuits (lighting, fans, small loads)
  • Runs where multiple conductors in a single jacket are helpful for organization
  • Areas where moisture or condensation is more likely (near exterior walls, floor cavities, or utility chases)

The flat triplex configuration also helps with cable management and routing, keeping related conductors bundled together in a clean, repeatable way.

Notes for Future Evaluation

  • Confirm ampacity and voltage drop for planned circuit lengths and loads.
  • Compare cost versus standard automotive primary wire and duplex marine cable.
  • Plan routing paths to take advantage of the flat triplex form factor.
  • Verify compatibility with planned fuse blocks, terminals, and distribution hardware.

This page is intended as a reference for the type of wiring being considered.
Final wire selection will be made after the electrical layout and load calculations are fully defined.

EcoFlow DELTA Pro 3 – Portable Power Station

EcoFlow DELTA Pro 3 – Portable Power Station (Reference for Consideration)

As I continue evaluating electrical system options for the cargo trailer conversion, I am now considering a broader EcoFlow ecosystem that includes the
DELTA Pro 3 Portable Power Station, the EcoFlow Smart Generator 4000 (Dual Fuel), a 50‑amp shore power inlet, and a future solar charging setup (roof‑mounted or portable).
This post documents the DELTA Pro 3 as a potential core component of that system.

This page is for reference only. I have not selected this unit for the build, but I am documenting it here as a potential option worth evaluating.

Product Overview

The EcoFlow DELTA Pro 3 is a high‑capacity portable power station designed for home backup, off‑grid use, and mobile applications. It combines a large lithium iron phosphate (LFP) battery, inverter, charger, and distribution system into a single integrated unit.

  • Model: EcoFlow DELTA Pro 3 (UL9540 Certified)
  • Price: $3,199.00 (at time of reference)
  • Battery Capacity: 4096Wh (4kWh)
  • Battery Chemistry: LFP (Lithium Iron Phosphate)
  • Cycle Life: 4000+ cycles to 80% capacity
  • Output Power: 4000W continuous, 6000W with X‑Boost
  • Voltage: 120V / 240V split‑phase capable
  • Expandability: Up to 48kWh with additional batteries
  • Charging Methods: AC, solar, generator, EV charger, vehicle
  • UPS Function: 10ms transfer time

Additional Components Under Consideration

EcoFlow Smart Generator 4000 (Dual Fuel)

To support extended off‑grid use, I am also considering the
EcoFlow Smart Generator 4000 (Dual Fuel).
This generator integrates directly with the DELTA Pro 3 ecosystem and provides automatic or manual charging when solar or shore power is unavailable.

  • Dual Fuel: Gasoline or propane
  • Smart Charging: Automatically charges the DELTA Pro 3 when battery levels drop
  • High Output: Designed for fast, efficient charging
  • EcoFlow Integration: Controlled through the app or linked directly to the power station

50‑Amp Shore Power Inlet

I am leaning toward installing a 50‑amp shore power inlet on the trailer.
This would allow the DELTA Pro 3 to charge quickly from campground hookups or home power, while also providing a stable AC source for high‑demand appliances.

Solar Charging (Portable or Roof‑Mounted)

Solar will be part of the system, though I have not yet decided between:

  • Portable solar panels for flexible positioning and maximum sun exposure
  • Roof‑mounted solar array for convenience and continuous charging while parked

The DELTA Pro 3 supports high‑wattage solar input, so either option—or a combination—can be integrated.

Why This System Is Worth Considering

The DELTA Pro 3 ecosystem offers several advantages for a cargo trailer conversion, especially for a build that prioritizes simplicity, modularity, and safety.

  • Plug‑and‑play operation: No need to design or wire a full inverter/charger/battery system.
  • High output power: Capable of running HVAC, induction cooking, and other heavy loads.
  • Expandable capacity: Additional batteries can increase total storage up to 48kWh.
  • Multiple charging options: Shore power, solar, generator, EV charger, or vehicle alternator.
  • UL9540 certification: Provides a high level of safety for indoor installation.
  • Integrated generator support: The Smart Generator 4000 adds reliable backup charging.
  • Portable and removable: The system can be taken out of the trailer if needed.

Limitations to Keep in Mind

  • Recharge dependency: Solar, shore power, or a generator is still required for extended off‑grid use.
  • Cost: Higher upfront price compared to a DIY battery/inverter system.
  • Weight: Large portable units add significant weight to the trailer.
  • Integration limits: May not replace every component of a full RV electrical system.
  • Generator noise: Even efficient generators produce some noise during charging.

How This Could Fit Into the Trailer Build

If selected, the DELTA Pro 3 would serve as the primary power hub for the trailer.
The Smart Generator 4000 would provide backup charging, the 50‑amp shore inlet would support fast AC charging, and solar would maintain battery levels during daily use.

This approach simplifies the electrical system while still offering enough power for HVAC, appliances, and tools planned for the build.

Notes for Future Evaluation

  • Confirm output capacity aligns with HVAC and appliance requirements.
  • Evaluate total weight and placement inside the trailer.
  • Compare cost and flexibility against a traditional inverter + battery bank system.
  • Determine solar capacity and whether portable or roof‑mounted panels make more sense.
  • Review generator noise levels and fuel storage considerations.

This page will continue to evolve as I refine the electrical system design and evaluate the full EcoFlow ecosystem for the build.