To calculate battery drain time, divide the battery’s capacity in ampere-hours by the power consumption of the device in watts. The result is the number of hours the battery will last.

## Battery Drain Time Calculator

Enter any 2 values to calculate the missing variable

The **Battery Drain Time Calculator** helps you determine how long your battery will last when powering an appliance or device. Knowing the battery capacity and the power requirement of your device, you can easily estimate the run time. This is crucial for battery-operated systems, such as solar setups, appliances, and portable devices, to avoid unexpected power loss.

**Formula:**

Contents

$T = \frac{C}{P$

Where:

**T**= Time the battery will last (hours)**C**= Battery capacity (Ah – Ampere hours)**P**= Power consumption of the device (Watts)

**How to Calculate ?**

**Determine the battery capacity (C)**: This is usually provided in ampere-hours (Ah) and is indicated on the battery.**Find the power consumption (P)**: Identify the power draw of the device in watts.**Apply the formula**: Divide the battery capacity (C) by the power consumption (P) to find the run time in hours.

**Solved Calculations**

**Example 1:**

Variable |
Value |
---|---|

Battery Capacity (C) | 200 Ah |

Power Consumption (P) | 400 Watts |

$T = \frac{200}{400} = 0.5 \, \text{hours}$

**Answer**: The battery will last 0.5 hours (30 minutes).

**Example 2:**

Variable |
Value |
---|---|

Battery Capacity (C) | 150 Ah |

Power Consumption (P) | 600 Watts |

$T = \frac{150}{600} = 0.25 \, \text{hours}$

**Answer**: The battery will last 0.25 hours (15 minutes).

**What is Battery Drain Time Calculator ?**