How to Calculate Kilowatt-Hours When Using a 72V Battery with an Inverter

Understanding the Basics: Voltage, Inverters, and Energy Conversion

If you're working with a 72V battery system and need to know how much electricity it can provide through an inverter, you're in the right place. Let's break down the math in simple terms – no electrical engineering degree required!

The Formula That Solves the Mystery

Here's what you need to calculate kilowatt-hours (kWh):

• Battery voltage (V) – in this case, 72V
• Battery capacity in amp-hours (Ah)
• Inverter efficiency (typically 85-95%)

Pro Tip: Always check your battery's spec sheet for accurate amp-hour ratings.

Real-World Calculation Example

Let's say you have:

• 72V lithium battery
• 100Ah capacity
• 90% efficient inverter

Calculation steps:

1. Calculate watt-hours: 72V × 100Ah = 7,200Wh
2. Apply inverter efficiency: 7,200Wh × 0.90 = 6,480Wh
3. Convert to kilowatt-hours: 6,480Wh ÷ 1,000 = 6.48 kWh

Quick Reference Table

Battery Capacity (Ah)	Usable Energy (kWh)
50Ah	3.24 kWh
100Ah	6.48 kWh
200Ah	12.96 kWh

Why This Matters for Your Energy System

Knowing your system's kWh capacity helps with:

• Estimating backup power duration
• Sizing solar panel arrays
• Calculating energy costs

"A 72V system's higher voltage means lower current draw, reducing energy loss in cables – especially valuable in large installations."

Industry Applications

Solar Energy Systems

72V battery banks paired with inverters are popular in:

• Off-grid solar installations
• Commercial backup power systems
• Telecom tower power supplies

Electric Vehicle Conversions

Many EV converters use 72V systems because:

• Balances power and safety
• Compatible with common motor controllers
• Easier to source components

FAQ: Your Questions Answered

Q: How long will a 72V 100Ah battery last? A: It depends on your load. A 1,000W appliance would run about 6.5 hours (6.48 kWh ÷ 1kW).

Q: Can I connect multiple 72V batteries? A: Yes! Connect in parallel to increase capacity while maintaining 72V.

Key Takeaways

• Always factor in inverter efficiency
• Higher voltage systems reduce energy loss
• Proper sizing ensures system reliability

Remember: A 10% difference in inverter efficiency can mean hundreds of kilowatt-hours lost annually in large installations!