Mr Calcu | Get accurate battery runtime in seconds—perfect for planning off-grid, backup, or portable power needs.
Calculate battery runtime instantly and optimize your power usage. Gain peace of mind with this precise, easy-to-use battery life estimator.
Battery Life Estimator Description
Battery Life Estimator Tool
The Battery Life Estimator helps you determine how long a battery can power a device under specific conditions. This is crucial for professionals designing backup systems, off-grid electronics, or portable setups.
Key Inputs
- Battery Capacity (Ah): Total charge the battery can deliver.
- Battery Voltage (V): Nominal voltage rating of the battery.
- Device Power (W): Power draw of the connected device.
How It Works
Use the following formulas:
Runtime (hours) = (Battery Capacity (Ah) × Battery Voltage (V)) / Device Power (W)
Or if using current draw directly:
Runtime (hours) = Battery Capacity (Ah) / Discharge Current (A)
Pro Tip: Always include 10–20% safety margin for real-world inefficiencies like inverter loss, aging batteries, or cold weather effects.
Real-World Factors Affecting Runtime
- Discharge Rate: Higher current draw reduces actual capacity.
- Temperature: Cold lowers efficiency; heat accelerates wear.
- Battery Age: Older batteries hold less charge.
- Internal Resistance: Increases voltage drop under load.
- Conversion Losses: Inverters lose 10–20% of energy.
Case Study 1: Off-Grid Surveillance
- Battery: 100Ah, 12V
- Device Power: 15W
- Estimated Runtime: (100 × 12) / 15 = 80 hours
- Adjusted for cold weather: ~64 hours
Case Study 2: Medical Backup
- Battery: 75Ah, 12V
- Device Power: 90W (CPAP machine)
- Estimated Runtime: (75 × 12) / 90 = 10 hours
- Adjusted for inverter loss: ~8.5 hours
Start planning smarter—calculate your battery life now and power your devices with confidence.