Capacidade bateria
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
I × horas
About this calculator
The battery capacity calculator helps determine the amount of energy stored in a battery. It uses the formula Ah = I × t, where Ah is the capacity in ampere-hour, I is the electric current in amperes, and t is the discharge time in hours. This calculation is useful for electronic projects, electric vehicles, or selecting the ideal battery for a device.
It works by multiplying the current consumed by a device by the time the battery can power it. For example, if a device draws 2A and the battery lasts 5 hours, the capacity will be 10 Ah. This allows sizing equipment autonomy and planning replacements or recharges.
Use this calculation in practical scenarios, such as checking if a battery supports a drone for 30 minutes or if a laptop charger provides power for 8 hours. Cautions: avoid fully discharging lithium-ion batteries and always check the manufacturer's technical specifications before using theoretical values.
Frequently asked questions
What does ampere-hour (Ah) capacity mean?
Ampere-hour (Ah) measures the amount of energy a battery can store, indicating how long it can maintain a constant current before discharging.
How to measure the current (I) of a device?
Use an ammeter in series with the device, ensuring it's turned off during measurement to prevent equipment damage.
Can I use this calculator for lithium-ion batteries?
Yes, but note that lithium-ion batteries have limited cycles and lose capacity over time, so the theoretical calculation may vary in practice.
Why is real-world usage time often shorter than calculated?
Energy conversion efficiency, thermal losses, and temperature variations affect real capacity, especially in extreme conditions.