July 2023 - Article

July 21, 2023
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The Brick reads capacity, CCA and SoC

The starter battery is the most service prone part in a vehicle. A “No Go” happens suddenly without warning. How can we make the starter battery more reliable? The secret lies in capacity measurement

When a German luxury car maker tested a large pool of starter batteries, it became apparent that 9 out of 10 failures were caused by low capacity. Capacity loss goes unnoticed until the battery lacks the energy required to crank the engine. 

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Most service prone part

To achieve reliable operation, a starter battery requires a Minimal Operational Reserve Energy (MORE) of 40%. Meeting this capacity level gives a grace period of about one year, good to next service. A fail below 40% calls for replacement, even if CCA is high.

The ability to read capacity gives the Spectro Modular (Brick) an advantage over competitive battery testers relying on resistance. The Brick measures capacity and CCA by Electrochemical Impedance Spectroscopy (EIS), a technology that ushers in a new era in battery testing. The non- invasive frequency scan creates a Nyquist plot that is modeled against a reference matrix to calculate capacity, CCA, and SoC. Test results are shown on a host. Cloud analytics is optional.

Calculating Grace Period of a Starter Battery

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Most starter batteries reach end-of-life by low capacity

A capacity threshold of 40% works well for cars. Trucks and buses may require higher settings when hotel load is used.

The non-invasive EIS test works especially well for large batteries. Scanning ability down to a frequency of 0.1 Hertz allows testing batteries of up to 300Ah.

Taking the electro-chemical evidence also complements the BMS as an on-board BMS cannot read battery capacity.

Test Methods

Most automotive testers check CCA by reading the internal battery resistance. CCA tends to stay high while capacity gradually fades without drop in performance.

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Use of tools demands skill

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The Brick does one thing best — verifying capacity to get Battery Peace

Connectivity

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The battery test results are shown on a host with printing capability. Connection is by Bluetooth. 

Cloud connectivity enables analytic work to study battery performance that may relate to geographic regions and battery usage. 

Starter batteries are serviced with a 12V generic matrix. Contact Cadex for batteries with higher voltages, including lithium-ion.

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