In this article, AutoTest takes a look at the challenges of battery testing and offers a solution

The electric charge your battery carries will not last a century – it can only carry so much electric charge for a specified amount of time and sooner or later it will discharge. In most cases, it is quite difficult to tell how much electric charge you have left.
AutoTest explains that state-of-health is not measured, but instead is estimated based on available symptoms.
It says that when testing a battery and trying to determine the state of health you must consider capacity (ability to store energy), internal resistance (ability to deliver current) and self-discharge (cell integrity and health).
The top indicator of a battery’s health is capacity (energy storage). A new battery should deliver 100 percent of the rated capacity.
This means a 10Ah pack should deliver ten amps for one hour, so if the battery fails to perform after 20 minutes, then the capacity is only 33 percent.
Lead acid starts at about 85 percent and increases in capacity through use before the long and gradual decrease begins, whereas Lithium-ion starts at peak and begins its decline immediately, but at a very slow pace.
Knowing when to replace a battery is difficult, as battery problems only become apparent with increased breakdowns, which may be caused by a lack of battery maintenance.
AutoTest says more than 40 percent of all roadside car failures are battery-related, and 30 percent involve either a discharged or defective battery.
Additionally, it says only a few starter batteries reach the average age of five years and the most common reason for battery failure is undercharge or sulfation. Further, failure during the warranty period is uncommon, with driving habits the main culprits.

The challenge of battery testing
AutoTest says the key problem lies in the difficulty of testing batteries, and this applies to repair shops, retail outlets, and service garages.
It states there is a significant shortfall in a reliable method of estimating the state-of-charge, which is based mostly on voltage and charge counting.
Assessing capacity is the leading health indicator of a battery and measuring the open circuit voltage and checking the internal resistance do not provide conclusive evidence of battery state-of-health.
While a dead battery is easy to check and most testers are 100 percent accurate, the challenge comes in evaluating a battery in the 80–100 percent performance range while in use.
AutoTest says most service and repair workshops struggle to introduce good battery test procedures, but says this is where its Battery System tester can assist.

The AutoTest BST-380 Battery System Tester 
The AutoTest BST-380 Battery System Tester uses the adjustable load test to decide whether a battery is still usable or needs to be replaced.
These testers measure the voltage drop when a voltage load that is half the battery’s CCA rating is used. The load is applied for about 15 seconds and the voltage drop is measured.
If the drop reading does not fall below 9.6 volts, then the battery is ideally conditioned, and is therefore, considered good.
AutoTest explains that it not only gives a complete view of battery health, but is a conveniently portable, easy to use battery analysis tool designed for automotive service, fleet maintenance and breakdown assist diagnostic use which takes the guess work out of battery diagnosis and alerting you to replace batteries before they fail.
The Battery System Tester is a professional quality unit that tests all 12V auto batteries, including new auxiliary batteries for hybrids.
It uses advanced conductance testing technology to easily, quickly and accurately measure the actual cold cranking amps capability of the vehicle starting battery, the health of the battery itself, and common faults in the vehicle starting system and charging system.
It can help maintenance personnel to identify problems quickly and accurately, thus leading to efficient vehicle repair.

Key AutoTest Battery System Tester features and benefits:  
• User friendly
• Built in Printer for an instant printout
• Test 12V/24V/30V batteries
• 100-2000 CCA (cold cranking amps)
• Polarity Reverse Protection
• Testing standards include a majority of the world’s battery standards, CCa, BCi, Ca, mCa, JiS, Din, ieC, en, Sae and G
• Stores 100 test results
• In-built real time clocks
• Registered Australian Made and Owned

Test functions include:
• Battery Test
• Charging System Test
• Start System Test
• Maximum Load Test
• Cranking Mode
• QC Mode

For more information, visit www.autotest.net.au