Battery Amp Hours Calculator
Learn how to compute ampere hour, determine amp hours, and calculate battery Ah for UPS, inverter, and solar systems. This tool also shows total energy in Watt-hours (Wh) and can convert reserve capacity to Ah.
Calculate Battery Amp Hours (Ah)
What Are Amp Hours (Ah)?
Amp hours (Ah) measure how much current a battery can deliver over time. Knowing Ah helps you size batteries correctly for UPS, inverter, and solar systems.
Battery Ah Calculation Formula
Amp Hours (Ah) = Load Current (A) × Time (Hours)
Or if you know reserve capacity (RC in minutes):
Amp Hours (Ah) = (Reserve Capacity × 25) ÷ 60
Practical Examples of Ah Calculation
- LED Light: 2A × 5h = 10Ah
- Fan: 3A × 6h = 18Ah
- Total Required Capacity = 28Ah
- Reserve Capacity Example: 120 min → (120 × 25)/60 = 50Ah
Battery Total Energy (Wh)
Energy (Wh) = Voltage (V) × Amp Hours (Ah)
| Voltage | Capacity | Total Energy |
|---|---|---|
| 12V | 100Ah | 1200Wh |
| 24V | 100Ah | 2400Wh |
| 48V | 100Ah | 4800Wh |
Why Battery Ah Calculation Is Important
- Correct battery sizing
- Longer battery life
- Accurate backup time estimation
- Efficient solar and inverter systems
