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!