Many workshops, do not carry out a complete battery health check, during routine maintenance. The first time any checks are performed, is when problems arise. When the temperature drops, customers notice issues starting and other various electrical problems with their vehicles.

The simple sensor mounted on the negative battery terminal, is responsible for monitoring the state of health and charge of the battery, and can notify the driver of any issues. This sensor can be easily damaged by an incorrect boost start procedure. Often, but not always, warnings will be labelled next to the battery.

In the past, a simple battery drop tester would be sufficient to condemn a battery, but now we have much more complex battery technology in modern vehicles. Accordingly, battery testing has also changed.

The Correct Battery
The correct battery for the vehicle application is vital for the correct operation. Stop-Start systems require a suitable battery. An Absorbent Glass Matt (AGM) or Enhanced Flooded Battery (EFB) must be fitted.

Battery Testing
The equipment to test this resistance is a very specific tool called a milliohm meter. A normal ohm meter does not have the resolution for this type of test. There are specific battery testers available on the market that will complete the milliohm test and report the state of health and charge. There are testers that connect via Bluetooth to measure and report complete battery life information. They can send the report directly to the customer, or to your service records for the car.

Test equipment will not drop-test these batteries, but will apply an AC frequency across the terminals, to measure the internal resistance and capacitance. Resistance is an indicator of battery health. Too high of an internal resistance will indicate a poor battery. Typical internal resistance values are below 5 milliohms.

One capable tester is the Launch BTS360. With a simple Bluetooth connection to an app on your phone, it measures and reports complete battery life information, and can send the report directly to the customer.

Battery Replacement
It is good practice to keep the vehicle alive when replacing the battery. This avoids the need to reset certain systems and sensors, as this can cause extra unnecessary work. One recent tool that is very popular is the Power probe PPDRAW. Not only can it maintain system power during battery change but also reports the parasitic load at the same time.

After replacing a battery, the vehicle's onboard battery monitoring system has to be reset. Not doing this basic reset can end up damaging the new battery.

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