Effective EV Battery Health Test Routine

Upgrading Your Diagnostic Tools

To perform the original equipment (OE) EV battery health test routine, you may need to unlock the Security GateWay (SGW) depending on the brand. However, older diagnostic tools like the DS150 and DS450 cannot access this feature.

For this reason, we highly recommend upgrading to a DS180 or DS480 solution. These newer tools enable you to perform comprehensive tests and access the SGW for detailed diagnostics.

Comprehensive EV Battery Health Testing

Delphi has defined EV battery health testing across seven categories:

Voltage Test (No Load)

This measures the voltage of each module or cell without any load.

You can then compare the voltages; a variance greater than 40mV warrants further investigation.

Voltage Test (Light Load)

This looks at the voltage under a light electrical load, typically under 10kW. It helps identify voltage stability under normal operating conditions.

Voltage Test (High Load)

Using this test, you can monitor voltage during full acceleration. A major voltage drop indicates poor cell or module capacity.

Capacity Test (Ah)

You can drain the battery to its cutoff voltage and then recharge it. During this process, you can measure the actual capacity and compare it to the original specification.

Thermal Test

This test checks the battery's thermal management system for leaks. You can ensure the coolant or refrigerant is functioning correctly.

Integrity Test (Pressure)

Use this category to check the physical integrity of the battery pack. It uses pressure or vacuum tests to inspect the casing for external breaches.

Internal Inspection

Finally, this test involves a visual inspection of all connections, joints, and the casing. This is typically done during battery repair or refurbishment.

How These Tests Tie Into Battery Classifications and Components

To give you some more context on these tests and how they work together, let's break down the basics of EV batteries.

Battery Classifications

EV batteries are categorised based on their voltage and configuration:

• High voltage (HV) batteries range from 48V to 1,000V.
• Cells are the building blocks of the battery and are usually between 1.2V and 4.2V each.
• Modules are groups of cells that work together.
• Packs are multiple modules that form the complete battery pack.

Knowing these components helps you see where each test fits in and why it matters. For example, understanding cell configurations (series vs. parallel) can help you clarify why certain voltage drops happen during a high-load test.

Battery Components 

The main components of an EV battery include:

• Cells
• Coolant/refrigerant
• Heating elements
• A sealed case
• Connections
• Relays
• The Battery Management System (BMS)
• Current sensors
• Temperature sensors

Each of these parts contributes to the battery's performance and safety. For example, the BMS monitors the state of the battery and ensures it operates within safe limits. Current sensors measure the flow of electricity, and temperature sensors keep track of the battery's heat levels to prevent overheating.

The OEM test

Different OEM’s have different tests categories within the BMS, this is the test that the Delphi diagnostic solution can access.

Some OE’s chose a simple light load voltage test, others carry out a more in-depth voltage and capacity test. 

Whichever it is, the Delphi diagnostic solution has you covered.

At the Forefront of Your Industry

Using the latest tools and following recommended test routines positions you at the forefront of the EV revolution. Upgrade your diagnostic tools today, and make sure your workshop is ready to handle tomorrow's demands.