Battery Charge Time Calculator
Estimate how long a battery needs to charge using its capacity, charging current, current state of charge, and battery chemistry efficiency.
The formula matches the Omni reference: available capacity divided by effective charging current.
Estimated Charge Time
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Run the calculation to see the full charging estimate.
Quick Answer
This calculator estimates the time required to charge a battery from its current state of charge to full using the effective charging current.
How to Calculate
- Enter the battery capacity and choose the unit.
- Enter the charging current and choose the unit.
- Set the current state of charge and battery type.
- Click Calculate to get hours and minutes.
Formula
Available capacity = capacity × (1 - state of charge / 100)
Effective charging current = charging current × efficiency
Charge time = available capacity / effective charging current
Worked Examples
Example 1: 200 Ah, 40% SoC, 48 A, 95% efficiency gives about 2.63 hours.
Example 2: 5,000 mAh, 20% SoC, 1,000 mA, 95% efficiency gives about 4.21 hours.
Example 3: 60 Ah, 50% SoC, 10 A, 85% efficiency gives about 3.53 hours.
How to Interpret the Result
| Output | Meaning |
|---|---|
| Hours and minutes | Estimated charging duration under the selected current and efficiency assumptions. |
| Higher time | The battery is larger, emptier, or charging more slowly. |
| Lower time | The battery is smaller, already partially charged, or charging faster. |
Frequently Asked Questions
Related Calculators
References
- OmniCalculator reference page
- The formula uses available capacity and effective charging current, as shown in the reference calculator.
- Last reviewed: March 2026.