Battery Life Calculator
Calculate how long your battery will last or find the right battery capacity for your needs.
Battery Details
V
Accounts for power loss (typical: 80-90%)
Common Devices:
Estimated Battery Life
8h 30m
8.50 hours (510 minutes)
Effective Capacity
4250 mAh
Energy
18.50 Wh
Power Details
Device Power1.85 W
Efficiency Loss15%
At 4hrs/day use2.1 days per charge
Battery Tips
- Real-world battery life varies with usage patterns
- Lithium batteries degrade over time (80% after 500 cycles)
- Temperature affects battery performance significantly
- Always add 20-30% margin for safety
Understanding Battery Specifications
Capacity Units
- mAh (milliamp-hours): Most common unit for small batteries
- Ah (amp-hours): Used for larger batteries (1 Ah = 1000 mAh)
- Wh (watt-hours): Energy capacity (Wh = Ah x V)
Formula
Runtime (hours) = Battery Capacity (mAh) / Device Current (mA)
Example: 5000 mAh battery / 500 mA device = 10 hours