# Usable Battery Energy Calculator

Separate nominal stored energy, usable DC energy and estimated AC output.

[Open this tool](https://whatson.pk/usable-calculator/)

Category: Solar & Battery

Stored energy, usable DC energy and estimated AC output are different stages of the battery calculation.

Begin with rated nominal capacity and apply health, discharge and conversion factors only once. Review each reduction before comparing storage options.

## Inputs and controls

* Capacity format: Nominal kWh; Voltage and amp hours
* Nominal capacity (kWh). Allowed range: 0.001 to 10000000
* Bank voltage (V). Allowed range: 0.1 to 2000
* Bank capacity (Ah). Allowed range: 0.01 to 10000000
* Usable depth of discharge (%). Allowed range: 0.01 to 100
* Retained capacity / state of health (%). Allowed range: 0.01 to 100
* DC to AC efficiency (%). Allowed range: 0.01 to 100

## How to use

* Choose capacity format. Enter nominal capacity, bank voltage and bank capacity.

* Enter usable depth of discharge, retained capacity / state of health and DC to AC efficiency.

* Select Calculate result. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.


## Why use this tool

The staged result makes it easier to see which assumption removes capacity at each point.


## Before relying on the result

State of health scales nominal capacity before DoD. AC output excludes inverter idle draw. Enter rated nominal energy rather than already reduced usable energy.


## Tool limitations

State of health scales nominal capacity before DoD. AC output excludes inverter idle draw. Enter rated nominal energy rather than already reduced usable energy.

## Questions

### Should I enter an already reduced usable capacity?

No. Enter nominal energy on the stated basis. Otherwise the later reductions can be applied twice.

### What should I check before using Usable Battery Energy Calculator?

Check Capacity format, Nominal capacity, Bank voltage and Bank capacity. Use the exact units shown beside the controls and replace any example values with your own inputs.

Source page last modified (UTC): 2026-10-01T18:56:35+00:00

This profile describes the tool. It does not execute it or supply a professional certification.