1. What is the Battery Capacity Formula?

The battery capacity formula calculates the required amp-hour (Ah) rating of a battery needed to power a 3000W inverter for a specified duration, accounting for system voltage and a safety factor.

2. How Does the Calculator Work?

The calculator uses the battery capacity equation:

Where:

• 3000 — Wattage of the inverter
• Time — Desired runtime in hours
• V — System voltage (typically 12V, 24V, or 48V)
• Safety Factor — Typically 0.7-0.8 to account for inefficiencies

Explanation: The equation converts watt-hours to amp-hours while accounting for system voltage and derating for real-world conditions.

3. Importance of Proper Battery Sizing

Details: Correct battery sizing ensures your inverter can handle the load for the desired duration without over-discharging the batteries, which can significantly reduce battery life.

4. Using the Calculator

Tips: Enter desired runtime in hours, system voltage in volts, and safety factor (typically 0.8). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical safety factor value?
A: Most systems use 0.7-0.8 to account for inverter inefficiency, voltage drop, and battery aging.

Q2: How does voltage affect battery capacity?
A: Higher system voltages require lower Ah capacities for the same wattage, as power = voltage × current.

Q3: What battery type is best for inverters?
A: Deep cycle batteries (AGM, Gel, or Lithium) are recommended as they handle deep discharges better than starter batteries.

Q4: Should I oversize my battery bank?
A: Yes, it's recommended to have 20-50% extra capacity to avoid deep discharges and extend battery life.

Q5: How does temperature affect battery capacity?
A: Cold temperatures reduce available capacity, while high temperatures increase capacity but reduce battery lifespan.