SuperCalX

Battery Size Calculator

Calculate the required battery capacity for a specific load and runtime.
Calculator
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Analysis
Interpretation of the current calculator output

Enter values to see detailed analysis and insights.

How to Use

Step-by-step instructions
  1. 1Enter the load current (Amps).
  2. 2Enter the desired runtime (Hours).
  3. 3Enter the safe Depth of Discharge (e.g., 50% for Lead Acid, 80% for Li-ion).
  4. 4The calculator will show the required battery capacity.

Capacity Sizing

Determines the total battery capacity needed by dividing the total energy required by the safe Depth of Discharge (DoD) percentage.
Capacity (Ah) = (Load × Time) / DoD

Variables:

LoadCurrent in Amps
TimeRuntime in Hours
DoDDepth of Discharge (decimal)

Example

Solar Storage

Inputs:

Load:1 A
Time:10 hrs
DoD:50%

Steps:

  1. 1.Total Load = 1 * 10 = 10 Ah
  2. 2.Required = 10 / 0.50 = 20 Ah
Result:
20 Ah

Frequently Asked Questions

What is DoD?

Depth of Discharge is how much of the battery's capacity you use. Regularly draining a battery to 100% (0% remaining) can damage it. Lead-acid batteries typically shouldn't go below 50%.