Test Results
Note: Most rapid-tests have been conducted on automotive (starter) batteries. This was done due to easy availability to prove the Spectro™ concept. test results on wheeled mobility (deep-cycle) batteries and traction batteries will soon be published also.
Note: Most rapid-tests have been conducted on automotive (starter) batteries. This was done due to easy availability to prove the Spectro™ concept. test results on wheeled mobility (deep-cycle) batteries and traction batteries will soon be published also.
Capacity readings approach laboratory standards
To verify the accuracy of the reserve capacity readings, Cadex prepared a test bed of 24 car batteries and measured the actual RC values of each battery (black line on chart). The test was based on the SAE J537 standard and consisted of a full charge, a rest period and a 25A discharge to 1.75V/cell, during which the reserve capacity was measured. The tests were then repeated with the Spectro™ technique (purple line) using model-specific matrices. The chart reveals close RC values done by discharge and Spectro™ methods
To verify the accuracy of the reserve capacity readings, Cadex prepared a test bed of 24 car batteries and measured the actual RC values of each battery (black line on chart). The test was based on the SAE J537 standard and consisted of a full charge, a rest period and a 25A discharge to 1.75V/cell, during which the reserve capacity was measured. The tests were then repeated with the Spectro™ technique (purple line) using model-specific matrices. The chart reveals close RC values done by discharge and Spectro™ methods
Reserve Capacity comparison of 24 batteries with model-specific matrix.
The purple line (Spectro™) follows the black line very closely.
The purple line (Spectro™) follows the black line very closely.
Repeatability of test results
Capacity readings of lead acid batteries are difficult to capture, even under the best circumstances. To verify the repeatability, Cadex tested 91 car batteries with diverse performance levels and plotted the results on the chart below. We prepared the batteries by giving them a full charge and a 24-hour rest period. We then measured the capacity by applying a 25A discharge to 10.50V or 1.75V/cell (black diamonds). The procedure was repeated for a second time and the resulting capacities were plotted (purple square). This produced a whopping +/-15% variation in capacity readings across the entire population. Some batteries produced higher readings the second time; others were lower.
Capacity readings of lead acid batteries are difficult to capture, even under the best circumstances. To verify the repeatability, Cadex tested 91 car batteries with diverse performance levels and plotted the results on the chart below. We prepared the batteries by giving them a full charge and a 24-hour rest period. We then measured the capacity by applying a 25A discharge to 10.50V or 1.75V/cell (black diamonds). The procedure was repeated for a second time and the resulting capacities were plotted (purple square). This produced a whopping +/-15% variation in capacity readings across the entire population. Some batteries produced higher readings the second time; others were lower.
Capacity fluctuations.
Capacities of 91 car batteries measured with a conventional discharge method show a fluctuation of +/-15%.
Capacities of 91 car batteries measured with a conventional discharge method show a fluctuation of +/-15%.
CCA Estimations
To verify CCA test results, Cadex tested 6 batteries using the following three test methods:
To verify CCA test results, Cadex tested 6 batteries using the following three test methods:
- CCA derived by the SAE J537 methods (black diamonds)
- CCA by the Spectro rapid-test method (red square)
- CCA by singe-frequency rapid-test method (blue triangle)
CCA readings
of 6 batteries.
Spectro™ (red) follows the CCA (black) readings closely. The single-frequency method (blue) shows large deviations.
Spectro™ (red) follows the CCA (black) readings closely. The single-frequency method (blue) shows large deviations.
State-of-charge compensation on CCA
Automotive batteries are often perceived faulty due to low charge. With the single-frequency methods, a low charge may also yield low CCA readings. To verify immunity to SoC, Cadex took the CCA readings of a starter battery at various SoC. As the chart indicates, Spectro™ provides reasonably stable results from 50-100% SoC (red squares). In comparison, the readings of the single-frequency method (blue diamonds) are severely affected by state-of-charge.
Automotive batteries are often perceived faulty due to low charge. With the single-frequency methods, a low charge may also yield low CCA readings. To verify immunity to SoC, Cadex took the CCA readings of a starter battery at various SoC. As the chart indicates, Spectro™ provides reasonably stable results from 50-100% SoC (red squares). In comparison, the readings of the single-frequency method (blue diamonds) are severely affected by state-of-charge.
SoC compensation
on CCA readings.
Spectro (red squares) provides robust CCA readings from 40-100% SoC. The single-frequency method (blue diamonds) is less consistent.
Cadex then took three batteries of various performance level and measured
the CCA of under different state-of-charge. The high performing battery F (green
diamonds) provides solid readings from 10-100% SoC; battery D (yellow triangles)
is steady from 40-100% SoC. The poorly performing battery C (pink squares)
provides less stable readings.Spectro (red squares) provides robust CCA readings from 40-100% SoC. The single-frequency method (blue diamonds) is less consistent.
Spectro™ performs CCA test of three batteries at various SoC levels.
High-performing Battery F provides solid readings from 10-100% SoC while marginal Batteries C and D are less tolerant to SoC.
Note:The capacity of these three batteries can be estimated on the number of test points per battery. Battery F produced the most as it took the longest to discharge.High-performing Battery F provides solid readings from 10-100% SoC while marginal Batteries C and D are less tolerant to SoC.
Reads capacity, conductivity and state-of-charge without discharging; reduces test time to seconds and finds hidden battery faults.
Find out more about how Cadex Battery Rapid Testers can help in these applications:
Find out more about how Cadex Battery Rapid Testers can help in these applications:
