A Simple but Important Tool for ADAS Work – The Battery Maintainer

Smart Express requires a battery support device to be used for all pre and post scan efforts. The primary battery support tool of choice is a battery maintainer.

Scanning and Battery Support: Power, Power, Power

Everything needs power to run. Pre and post-scans require power. And the vehicle’s battery is where you will get the power necessary for scan tools to perform pre and post-diagnostics of a car’s electronic system.

More importantly, a vehicle’s battery only has so much electricity. So what happens to a car’s electronics or devices using electricity when there isn’t enough current to run them? They shut down to avoid damage, are damaged, or stop running correctly.

Scanning and Battery Support

This leads to the subject of scanning and battery support. You should never assume that a vehicle’s battery has enough power to power a pre or post-scan. Why? Because if not enough power is present during a pre or post-repair scan, the diagnostics of damage or codes are flawed.

When brought into a shop, you don’t know how much power is in a car’s battery. You don’t know how long the engine ran post-crash. Or how long the car sat in the lot before delivery, if any power wires were cut, or if lights had been left on while it was parked.

Even when a vehicle is parked, the battery is powering the vehicle’s alarm system, computer systems, and other electrical features. All of this can drain power from the vehicle’s battery. The heat can drain the car’s battery if the weather is extremely hot. And a battery can lose its charge if it sits in the cold. The chemical reaction that generates electricity slows in the cold, yielding less power. Even in ideal temperatures, batteries slowly discharge. These are just some things that can drain a battery of power.

Furthermore, electronics are sensitive to surges, power drains, and changes in resistance; that’s how they detect problems. Computers and control modules must have the correct power to operate correctly. So when not enough power is available, car sensors detect this low current state and start shutting down non-essential electronics. This ensures critical components have enough current to function correctly; however, this would stop the tool’s ability to accurately read control modules and determine what was or is currently damaged.

And if you run out of power during a scan, you’ll have to start all over again, wasting time and money. Remember, performing the scan draws a lot of energy. A battery weak from the results of the crash, age, or use will compromise your scan or diagnostic results. So, never assume that a vehicle’s battery has enough power to power a pre or post-scan diagnostic process.

Battery Support is Required When Scanning a Vehicle.

When vehicle voltage levels fall below normal, diagnostic results are no longer accurate. Fluctuations in battery voltage can also cause additional codes to appear. So when an unsupported battery fails or fluctuates during programming, the programming may fail, or modules may be damaged, which can be costly, not to mention bias results.

The best way to not compromise your scan is to ensure enough power is in the battery. To do that, have a good, consistent power source hooked to the battery. Which means, the most crucial step before starting the scanning and diagnostics process is to provide proper battery support to the vehicle.

Maintainer Required for Correct Battery Support

For a successful scan, the battery must be supported and kept at a constant voltage. If the battery voltage drops below certain levels, the battery will shut down non-essential modules to preserve the ability to start the car. This low voltage scenario then creates a situation where the scan tool cannot read all of the available modules, thus affecting the scan’s quality and the report’s accuracy. Most manufacturers recommend power supply levels between 13.2-13.8V DC while in a programming session. Some European manufacturers require voltages over 14.0V DC to complete a programming session. For this reason, battery support is necessary when scanning a vehicle.

And a battery voltage maintainer is the singular choice for this type of battery support. A quality battery voltage maintainer provides the required uniform voltage (clean power) to power the vehicle and perform the required diagnostics and system reinstatement.

Battery Charger and jump Box Not Acceptable

Battery chargers or jump boxes are not recommended for use in these situations. These devices do not provide the proper battery support to the vehicle. Battery chargers can overcharge and “cook” a battery, and jump boxes can die or lose their charge over time. (Brick a module)

Battery Charger

A conventional battery charger can introduce voltage fluctuations and/or may have an AC voltage ripple that can affect the communication lines from the vehicle to the application software. Such conditions can prevent the programming event from completing and render the ECU permanently inoperative.

Jump Boxes

A battery “jump box” provides a steady voltage level but is generally too low to meet the OEM minimum voltage requirements and, as indicated, can go dead or lose its charge when needed the most.

The bottom line is to get the best and most reliable outcomes; before you begin any scanning process for diagnostic purposes, make sure that the car has proper battery support.


So, what is a battery maintainer? This tool dispenses a controlled amount of electricity to the battery over time while the car is inactive, ensuring that the battery always has enough charge to power the vehicle’s systems.

In some respects, a battery maintainer is similar to a battery charger. But the two products differ in key ways. A battery charger delivers a steady flow of electricity until the car battery is fully charged, and once charging is complete, it needs to be disconnected.

On the other hand, a battery maintainer monitors the charge, delivering more only when the battery’s voltage drops. Because of this, a battery maintainer can be left unattended while connected to a vehicle for an extended period without any damage to the battery or electrical system, which isn’t the case with a standard battery charger.

Only when the vehicle has proper battery support can the technician perform the proper diagnostic, and the technician 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.