Supporting the battery during diagnostic tests

Supporting the battery during diagnostic tests

3D Group explains why it’s essential technicians use the appropriate battery support when running diagnostic tests on a vehicle.

Imagine the following scenario: a vehicle has arrived at your workshop and you need to start the diagnostic or programming process. You start where you normally would by running a diagnostic test. You run a pre-scan of the vehicle to identify all of the DTCs – Diagnostic Trouble Codes; this is great. You now have a starting point for the repairs. However, a vehicle’s condition can often affect the vehicle’s battery displaying a low voltage. This condition may not allow all of the modules to be read, affecting the quality of the scan and the accuracy of the report.

For this reason, 3D Group suggests the use of battery support when scanning a vehicle. During diagnostic or programming operations, the vehicle’s systems are operated solely from the battery.

Battery support units provide a continual voltage to prevent data loss and possible damage to control units during diagnostic processes, software updates and module reprogramming.

Before running tests

The first and most crucial step is to provide adequate battery support to the vehicle before beginning any diagnostic and vehicle scans. Battery chargers or jump cables are not recommended as they cannot provide the proper battery support. It is also good to bear in mind that battery chargers can overcharge and damage a battery.


If the battery voltage drops below a certain level, the battery will start to shut down nonessential modules, allowing the vehicle to preserve the ability to start. Low voltage can create a situation where the scan tool might not be able to read all of the available modules.

Connecting an appropriate battery support tool to the vehicle battery will ensure that the battery will provide consistent voltage, which will allow you to provide the highest quality report and information to undertake the repairs or reprogramming.


A quality battery voltage maintainer provides stable voltage to the vehicle for more extended periods than an unsupported battery. The bottom line is to ensure that the vehicle has proper battery support before you begin any diagnostic or reprogramming tasks to provide the best possible outcomes.

When vehicle voltage levels fall below the normal levels, diagnostic results are no longer accurate – fluctuations in battery voltage can also cause additional codes to appear. If this does occur, it can cause the programming to fail, incurring extensive costs.

Additional uses

Not to forget there are additional uses for battery support units such as:

  • Charging: battery support units such as the 30 A GYSFLASH 30.12 PL can charge vehicle batteries (12 V Lead or Lithium (LFP)) from 5 to 1500 Ah
  • Showroom: battery support units provide power compensation when using the electrical accessories of a demonstration vehicle. It also manages the optimal charging of the battery
  • Tester: battery support units also allow technicians to check the battery voltage, evaluate the starting system (starter + battery) and the condition of the vehicle’s alternator

To recap, you can perform the relevant diagnostic and vehicle electronic scans only when the vehicle has proper battery support. A stable battery voltage ensures that you can generate the quality scan results and corresponding reporting necessary to provide the information needed to produce an accurate, efficient, and safe repair.

At the post-scan stage, battery support is required to ensure that all codes can be cleared, and additional codes aren’t introduced due to voltage fluctuations.

Want to know more? To see the full range of equipment offered by 3D Group, click here.

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