If your AVILOO FLASH Test shows a “Safety Risk – Potential Safety Hazard” warning and mentions a cell imbalance, this means that one or more cells inside your vehicle’s high-voltage battery are operating at significantly different voltages compared to the others.
What the Report Is Telling You
Every EV battery pack is made up of many smaller cells, grouped into modules.
During an AVILOO FLASH Test, each cell’s voltage is measured individually.
In a healthy battery, these cell voltages remain very close together — typically within 30–40 millivolts (mV) of each other.
If your certificate shows a “Delta” (difference) greater than 100 mV, as in the example below, the system flags this as a safety risk:
This voltage spread indicates that some cells are more charged than others, which is known as cell imbalance.
Why This Matters
An imbalanced battery can cause:
Reduced usable capacity – charging stops early because one cell hits its voltage limit first.
Shorter range – the vehicle’s available energy is limited by the weakest cell.
Potential overheating risk – extreme imbalance can cause stress on cells during charging or regeneration.
Inaccurate State of Health (SoH) readings – AVILOO suppresses the SoH score when a major imbalance is detected.
For this reason, a Safety Risk result overrides the normal battery score and requires further inspection.
Possible Causes
Cell imbalance can be triggered by several factors:
One or more deteriorating or faulty cells that the BMS can no longer balance.
A balancing circuit fault within the Battery Management System (BMS).
Extended storage or infrequent use, allowing small differences between cells to grow.
Previous deep discharge or high-temperature exposure that damaged one module.
Recommended Next Steps
Do not ignore the warning.
The red “Safety Risk” flag means AVILOO’s algorithms detected a measurable abnormality.Contact a qualified EV specialist or main dealer (e.g. Nissan-authorised workshop).
Ask them to:
Read out module voltages using a manufacturer diagnostic tool.
Check for DTCs relating to “Cell Voltage Deviation” or “Interlock Circuit.”
Attempt a balancing or calibration cycle if the hardware allows it.
Retest after service.
Once the vehicle has been inspected or balanced, run a new AVILOO FLASH Test to confirm the issue has been resolved.
Key Takeaway
A cell imbalance does not always mean battery replacement, but it does require expert assessment. Identifying and correcting it early helps protect the pack from further deterioration and ensures accurate State-of-Health readings in future tests.