Off-Grid Trailer Electrical System

Designed and built a complete off-grid electrical system for our tiny house on wheels, combining renewable energy with smart monitoring for reliable, sustainable power anywhere we travel.

The Challenge

Living in a mobile tiny house requires a robust electrical system that can:

• Generate sufficient power without grid connection
• Store energy for cloudy days and nighttime use
• Handle the vibrations and weather of constant travel
• Power modern appliances and electronics reliably

System Overview

Solar Generation

• 3.2kW solar array with 8x 400W monocrystalline panels
• Custom tilt-adjustable mounting system for seasonal optimization
• MPPT charge controllers for maximum efficiency

Energy Storage

• 800Ah LiFePO4 battery bank (10.24kWh usable capacity)
• Integrated BMS with temperature protection and cell balancing
• 5,000+ cycle lifespan

Power Distribution

• 3000W pure sine wave inverter for clean AC power
• Separate DC circuits for efficient LED lighting and 12V appliances
• Smart breakers with remote monitoring capabilities

Smart Monitoring

Built a comprehensive monitoring system using Victron components and custom software:

• Real-time power generation and consumption tracking
• Historical data analysis for usage optimization
• Remote monitoring via cellular connection
• Automated load shedding during low battery conditions

Key Features

• Weather-resistant: Survived multiple storms and temperature extremes
• Code compliant: Meets RVIA and NEC standards
• Expandable: Designed with future upgrades in mind
• Efficient: 99.8% uptime over 2+ years of continuous use

Results

The system has powered our off-grid lifestyle for over two years:

• Generates 8-16 kWh daily (season dependent)
• Eliminated all electrical utility costs
• Enabled true location independence
• Zero critical failures

Technologies Used

• Victron Energy components for reliability
• LiFePO4 batteries for safety and longevity
• Home Assistant for automation and monitoring
• Custom Python scripts for predictive energy management

Lessons Learned

Building this system taught me the importance of overengineering for reliability, the value of quality components, and how software can enhance hardware systems. The intersection of sustainable technology and practical engineering has made our mobile lifestyle not just possible, but comfortable.