Inverter Battery Calculator

Battery Capacity Formula:

\[ \text{Battery Capacity (Ah)} = \frac{\text{Inverter Load (W)} \times \text{Time (h)}}{\text{Voltage (V)}} \]

Battery Capacity:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Inverter Battery Calculator?

The Inverter Battery Calculator helps determine the required battery capacity (in ampere-hours) based on your inverter's load, desired backup time, and system voltage. It's essential for designing reliable power backup systems.

2. How Does the Calculator Work?

The calculator uses the following formula:

\[ \text{Battery Capacity (Ah)} = \frac{\text{Inverter Load (W)} \times \text{Time (h)}}{\text{Voltage (V)}} \]

Where:

\( \text{Inverter Load} \) — Total power consumption of connected devices (watts)
\( \text{Time} \) — Desired backup time (hours)
\( \text{Voltage} \) — Battery bank voltage (typically 12V, 24V, or 48V)

Explanation: The formula calculates how much current (in amperes) your system will draw over time, determining the battery capacity needed to sustain your load.

3. Importance of Battery Capacity Calculation

Details: Proper battery sizing ensures your power backup system meets your needs without over-investing in unnecessary capacity. Undersized batteries may not provide enough backup time, while oversized systems are unnecessarily expensive.

4. Using the Calculator

Tips:

Calculate total wattage of all devices you want to power
Determine how many hours of backup you need
Know your system voltage (common values are 12V, 24V, or 48V)
For lead-acid batteries, multiply result by 1.2-2 to account for depth of discharge limitations

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between Ah and Wh?
A: Amp-hours (Ah) measure charge capacity, while watt-hours (Wh) measure energy capacity. Wh = Ah × V. Our calculator gives Ah which is standard for battery ratings.

Q2: How does battery type affect capacity?
A: Lead-acid batteries typically shouldn't be discharged below 50%, while lithium can often go to 80-90% discharge. Adjust your calculations accordingly.

Q3: Should I add a safety margin?
A: Yes, we recommend adding 20-30% to the calculated value to account for inefficiencies and battery aging.

Q4: How does temperature affect battery capacity?
A: Cold temperatures reduce battery capacity. Below freezing, lead-acid batteries may deliver only 50-60% of rated capacity.

Q5: Can I connect batteries in series/parallel?
A: Series connections increase voltage (capacity stays same), parallel connections increase capacity (voltage stays same). Always use identical batteries when connecting.