Battery Runtime
Estimate battery runtime t from capacity (mAh) and load current (mA).
Inputs
Formula
t = capacity / current
Real runtime depends on C-rate and temperature.
Fundamentals
Estimate battery runtime t from capacity (mAh) and load current (mA).
This tool computes Battery Runtime from the formula: t = capacity / current
History
Design theory of gears, threads and bearings matured with machine tools and standardisation (AGMA, ISO) since the Industrial Revolution.
Engineering applications
Used for transmission design, joint strength checks and component selection.
Glossary
| Capacity | Input parameter |
| Load current I | Input parameter |
| Runtime t | Output result |
How to use
- Fill in Capacity, Load current I in the Inputs section (watch the unit on each field).
- Click Calculate; the tool evaluates the formula shown above.
- Read Runtime t in the results area.
Formula · Worked Example · Knowledge
Formula
核心计算关系：t = capacity / current
输入变量：
- Capacity
cap— mAh - Load current I
I— mA
输出结果：
- Runtime t
t— h
假设/适用：Gearing/thread formulas assume standard, zero-backlash mounting; include error & load factors K_A.
Worked Example
根据公式 t = capacity / current，取 Capacity = 2,000 mAh；Load current I = 200 mA。
代入计算得：Runtime t = 10 h。
Key Points
- Gearing/thread formulas assume standard, zero-backlash mounting; include error & load factors K_A.
- Compare stress with allowable stress and keep a safety factor (≥1.5, ≥2 for critical parts).
- For high speed/load also check lubrication, heat and fatigue life, not just static strength.
Parameters
Inputs
| Parameter | Symbol | Unit | Default |
|---|---|---|---|
| Capacity (mAh) | cap | mAh | 2000 |
| Load current I (mA) | I | mA | 200 |
Outputs
| Result | Symbol | Unit |
|---|---|---|
| Runtime t | t | h |
Applications
- Common engineering use cases
FAQ
What formula does this tool use?
This tool computes per ISO / AGMA / ASME standard formulas: t = capacity / current
How accurate are the results?
Results match input precision, based on SI units and common engineering approximations; for critical duty re-check with a safety factor.
Where is it used?
Common engineering use cases