1. What is Solar Battery Backup?

The solar battery backup calculation determines how much battery capacity (in amp-hours) you need to power your home based on your energy consumption, battery voltage, and desired depth of discharge.

2. How Does the Calculator Work?

The calculator uses the following equation:

Where:

• \( \text{House Load} \) — Your home's daily energy consumption in kilowatt-hours
• \( \text{Battery V} \) — Voltage of your battery bank (typically 12V, 24V, or 48V)
• \( \text{DoD} \) — Depth of Discharge (decimal from 0 to 1, typically 0.5-0.8)

Explanation: The equation converts your energy needs from kWh to watt-hours, then divides by the battery voltage and depth of discharge to determine the required amp-hour capacity.

3. Importance of Battery Sizing

Details: Proper battery sizing is crucial for solar systems to ensure you have enough power during periods without sunlight and to maximize battery lifespan by not exceeding recommended discharge depths.

4. Using the Calculator

Tips: Enter your average daily house load in kWh, your battery bank voltage, and your desired depth of discharge (typically 0.5-0.8 for lead-acid, 0.8-0.9 for lithium). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical DoD for different battery types?
A: Lead-acid: 50-80%, Lithium-ion: 80-90%, Saltwater: 100%. Check your battery specifications.

Q2: How do I determine my house load?
A: Check your electric bills for daily kWh usage or use an energy monitor to measure consumption.

Q3: What battery voltage should I use?
A: Common voltages are 12V (small systems), 24V (medium), or 48V (large). Match your inverter input.

Q4: Should I include days of autonomy?
A: This calculator gives daily requirements. Multiply by desired backup days for total capacity.

Q5: How does temperature affect the calculation?
A: Cold temperatures reduce battery capacity. In cold climates, you may need to increase capacity by 20-30%.