Battery Life Estimator: Calculate Duration by Usage and mAh/Wh
◎ SEOlust

Advanced Battery Life Estimator

Predict your device's total battery duration based on capacity, voltage, and a breakdown of your typical usage patterns (power consumption).

1. Device Battery Specifications

Milliamp-hours (e.g., 5000 mAh for a phone).

Volts (e.g., 3.7V for Li-ion, 12V for a car battery).

2. Define Usage Scenarios (Must total 100%)

Scenario Name Consumption (**W**) Usage (**%**) Est. Duration (H:M)
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**Tip:** Use lower wattage values for standby/sleep modes. Power (W) can be found in device specs or online reviews.

Current Total Usage %: 100

The Science of Battery Life Estimation

Predicting battery life requires converting the battery's stored chemical energy into electrical energy available for consumption, which is typically measured in **Watt-hours (Wh)**. The duration is then determined by the rate at which the device consumes this energy, measured in **Watts (W)**.

Key Calculations:

The fundamental relationship between capacity, voltage, and power consumption is governed by these formulas:

  1. **Energy Conversion:** Batteries are often rated in **mAh** (milliampere-hours), but this depends on voltage. We convert this to the universal energy unit, Watt-hours (Wh): $$ \text{Energy (Wh)} = \frac{\text{Capacity (mAh)} \times \text{Voltage (V)}}{1000} $$
  2. **Duration per Scenario:** The time a battery can run under a constant load is: $$ \text{Duration (h)} = \frac{\text{Energy (Wh)}}{\text{Power Consumption (W)}} $$
  3. **Weighted Average Life:** The final estimate is a **weighted average** of the duration of each scenario, based on the percentage of time you spend in that mode. This provides a much more realistic, composite estimate than a single maximum-drain test.