IDA

Battery Bank Sizer

Determine the required capacity for your battery bank.

Inputs

Wh

days

How many days the system should run without any charging.

%

Max percentage of capacity to be discharged. 50% for Lead-Acid, 80-90% for Lithium.

V

Outputs

Total Required Capacity
20
kWh
Total Required Capacity
416.67
Ah

System Diagram

System Schematic

Battery Bank20 kWh / 416.67 AhAppliance Load

Details

Description

This tool calculates the total battery capacity (in Amp-hours and kilowatt-hours) needed to meet your daily energy needs, considering desired autonomy and battery health.

Design Principles

1. Energy Storage: The bank must store enough energy to cover your daily consumption (Wh). 2. Autonomy: Sizing for multiple days of autonomy provides power during cloudy weather. 3. Depth of Discharge (DoD): Limiting DoD (e.g., to 50% for lead-acid) significantly extends battery lifespan. Lithium batteries can handle a much deeper DoD (80-90%).

Relevant Equations

Total Wh Capacity = (Daily Wh * Days of Autonomy) / (DoD / 100) Total Ah Capacity = Total Wh Capacity / Battery Voltage