What is a Truck APU System and How Does It Work?

Introduction

An Auxiliary Power Unit (APU) for trucks is a small power system that keeps your sleeper cab comfortable without running the main engine. Think of it as a backup generator specifically designed for long-haul trucking needs - providing air conditioning, heating, and electrical power during rest periods.

How Traditional APU Systems Work

Traditional truck APUs typically use a small diesel engine to generate electricity. While they consume less fuel than idling the main engine, they still:

• Burn diesel fuel continuously
• Require regular maintenance (oil changes, filters, belts)
• Generate noise and emissions
• Have many moving parts that can fail

The Modern Electric APU Solution

Electric APUs, like our A1, A2, and A3 series, work differently:

Basic Components:

• Large capacity LiFePO4 battery (460-560Ah for A1, or multiple 100Ah G31 batteries for A2/A3)
• 12.8V DC air conditioner (7,500-15,000 BTU cooling capacity)
• Battery charger (charges via the vehicle's engine; shore power functionality requires the purchase of an optional external charger)
• Optional heater and inverter (for complete climate control and AC power)

Operating Principle:

1. While driving, the battery charges from your truck's alternator. Our shore power charger can be purchased separately to meet specific needs.
2. During your 10-hour break, the battery powers the air conditioner directly
3. No engine running = no fuel consumption, no noise, no emissions
4. Next day, the battery recharges as you drive

Key Advantages

Cost Savings:

• Zero fuel consumption during rest periods
• Eliminates idle hours (typically 8-10 hours per night)
• At current diesel prices, saves $30-50 per night compared to idling
• Minimal maintenance costs

Compliance:

• Meets anti-idling regulations in California, New York, and other states
• No emissions during rest periods
• Reduces engine wear and hours

Comfort & Convenience:

• Silent operation
• Consistent cooling/heating power
• No engine vibration or noise
• Reliable overnight operation

System Specifications

Our electric APU systems operate on 12.8V DC power, which is the standard voltage for LiFePO4 (lithium iron phosphate) batteries. This voltage is compatible with truck electrical systems and provides:

• Runtime: 4-10 hours depending on configuration
• Cooling capacity: 7,500-15,000 BTU
• Recharge time: 4-8 hours of driving (varies by battery size)
• Lifespan: 3,000+ charge cycles (8-10 years typical use)

Who Benefits Most?

• Long-haul drivers who sleep in their trucks 4-7 nights per week
• Owner-operators looking to reduce fuel costs
• Small fleets (1-50 trucks) wanting to cut operating expenses
• Anyone operating in states with strict anti-idling laws

Next Steps

Choosing the right APU system depends on your specific needs:

• A1 Series: Ideal for maximum runtime and simplicity, featuring a single high-capacity battery
• A2 Series: Modular design that can be customized to fit your specific budget and needs
• A3 Series: Premium option with engine start-stop capability; when paired with our I3 3kW inverter, it delivers higher current and power output for demanding appliances

Need help selecting the right system? Our technical experts can guide you through the options based on your operation.