Introduction

Welcome! This battery size calculator will allow you to determine an appropriate battery size in Amp-hours given load, supplied voltage, duration, battery type and charge.
Choosing the most appropriate battery for a circuit is a critical choice in designing a selected circuit. The type of battery also plays a crucial part in implementing this.

Calculation

⬇️ Inputs



I
:2ampere



t
:20hours



Q
:50


⬆️ Outputs



B (Lith)
:80



B (Lead)
:173.913043



⛔️ No Load Current Given...

If the supplied load doesn't give a rated amperage, you can use the following calculation to manually determine the load current:

Where:



Rated power (W)
:5



Rated voltage (V)
:4



Rated current (A)
:1.25



💬 We'd love your feedback on this template! It takes 1min

Explanation

The most important specification of a battery is its current rating. The rated capacity of any battery expresses the average amount of current it releases over a period of time under normal use. For example, a 4000Ah battery can deliver 100 A for 40 hours.
The type of battery selected also plays an important role in battery size. Lead-acid batteries have a battery rating proportional to their discharge rate.

For lithium-ion batteries:

For lead-acid batteries:

Where:


Additional Resources

Check out our other calculators to calculate inductor reactance, generator fault current, and more!
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  1. 🔗 Transformer Full Load Current