Testing Batteries with a DC Electronic Load

Introduction

Because energy efficiency and reliability are important design criteria in most applications in today’s battery-intensive environment, it is important to use suitable test equipment capable of accurately measuring and displaying the results that define the performance of the batteries under test.

This is becoming a very intense area for research and development as products such as electric vehicles, 4G cellular phones, portable computers, and battery-powered drones become prevalent in modern society.

A popular device to accomplish this testing is a programmable DC electronic load, which will help you test various settings, configurations, schemes, and methodologies. This article concerns using a DC electronic load to test batteries.

Overview

Testing batteries under load is the optimal method for determining energy efficiency and battery lifetime. This reflects the energy efficiency of the battery power source. A standard test of performance consists of analyzing the discharge curves that represent the performance characteristics of the battery source under the conditions defined by the programmable DC load. Observing these curves allows the engineer to measure the battery life and compute the battery’s efficiency.

Some DC loads provide this feature to provide battery discharge measurements. The total charge is provided in Ah (Amp-Hours) to a specified voltage. Several of the  programmable DC electronic loads available from Circuit Specialists provide this useful built-in function, which enables you to quickly set up and test. Below is a description of a simple discharge test designed for testing consumer-grade “AA” sized batteries. This example can be applied to a wide variety of other battery types and configurations.

Setup

Step one is to connect the battery being tested to your electronic load. Both soldering wires to the battery or using a battery holder will work. You may use the software provided by the manufacturer of the programmable load or write a custom program using LabVIEW or SCPI commands so they can save the data points in real-time when the test cycle begins. Ensure that you have a suitable connection to your PC using an RS232 or USB cable.

DC Load Setup

The setup of the DC electronic load testing the battery is controlled by the software program. Be sure to manually set the voltage and current range before running the test program. If the current is quite large, you may want to use the remote voltage sensing feature of the DC load

Results:

The plot shown below is a simple example of the battery discharge curve for a consumer-grade “AA” alkaline battery tested with a DC programmable electronic load. This test was completed in constant current (c.c) mode with a ½ amp load and a cutoff voltage of 0.5 volts. If you look at the discharge curve, you can determine and analyze the behaviour of the battery and the battery’s capacity under this loading condition.

Wayne

It was 1971 when an amazing new device called the Integrated Circuit became the new big thing in electronic design and manufacturing, and the Thorpe family started their mail order catalog, Superconductor Supermart. Wayne is still active on a daily basis with Circuit Specialists, serving as a consultant and intermediary to all of its international vendors.

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