How to Calculate Battery Life
What is Battery Life?
Calculates battery runtime based on capacity, discharge rate, and device power consumption. Determines whether battery suits application.
Formula
Runtime = capacity ÷ consumption
Step-by-Step Guide
- 1Battery capacity in mAh or Wh
- 2Device power consumption in mA or watts
- 3Runtime = capacity ÷ consumption
- 4Account for temperature and age effects (10-20% penalty)
- 5Adjust for self-discharge over time
Worked Examples
Input
2000mAh, 500mA draw
Result
4 hours
Common Mistakes to Avoid
- ✕Using rated capacity without accounting for usable capacity
- ✕Ignoring temperature effects on performance
Frequently Asked Questions
Why does battery life differ from rated?
Temperature, discharge rate, load profile, battery age, and self-discharge all reduce actual runtime.
How do I extend battery life?
Reduce power consumption, optimize discharge rate, manage temperature, use lower drain modes.
Ready to calculate? Try the free Battery Life Calculator
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