Independent Diagnostics Trump BMS* Readout
A simple readout of battery health is not a reliable basis for professional decision making. Only independent battery diagnostics from AVILOO provide manufacturer-independent analyses at cellular level, supported by the most comprehensive EV battery database and certified procedures.
*BMS Battery Management System
Inaccurate Readings
Precise Testing
On this page
BMS Read-out VS.
Independent Battery Diagnostics
From Snapshot to
Standardized Transparency
The high-voltage battery accounts for a significant portion of the vehicle's value. Anyone who relies on a simple SoH value is making decisions blindly: when buying and selling, when returning leased vehicles, when making warranty promises, or when purchasing a vehicle privately.
Even professionals often overlook the fact that a read-out of the battery health is not comparable to a comprehensive and independent battery diagnosis.
During a standard readout, a tester or app only accesses data from the battery management system (BMS). The key factor here is the State of Health (SoH), which indicates the health of the battery as a percentage.
Battery State =
Biggest Value Factor in Electric Vehicles
Limits of Read-outs
It Sounds Straightforward, but There Are Limitations:
Manufacturer Logic Instead of Standard
Each OEM uses its own algorithms and thresholds. A SoH of 90% for manufacturer A may differ from 90% for manufacturer B.
Limited View Instead of Diagnosis
The SoH value only represents a snapshot. Whether individual cells are out of line, there are balancing problems, or anomalies are present remains invisible.
Potential for Distortions and Favorable Conditions
Software resets, updates, or certain charging profiles can affect how the SoH is displayed. The value is opaque and prone to distortion.
Only Independent
Diagnostics Create
Security
Independent battery diagnostics offer more.
Smart Diagnostics from AVILOO focus not on the display, but on the behavior of the battery.
The result is not just a percentage, but a diagnosis that can be explained and substantiated. Includes a certificate, clear benchmarks, and comprehensive risk indicators.
Key elements of an independent test include:
Standardized, Reproducible Test Methodology
same rules for all brands and models
Cell-level Analysis
instead of just one overall value, the behavior of individual cells and cell groups is considered
Big Data and AI-Supported Assessment
measured signals are compared with an extensive EV battery database
Objective, Manufacturer-Neutral Results
independent of OEM strategies or software versions
Read-out VS. Smart Diagnostics
In Comparison
Read-outs provide a number. Independent battery diagnostics provide a picture of reality.
Direct Comparison
Criterion |
SoH Read-outs (BMS / Standard Tools) |
Independent Battery Diagnostics 
|
|---|---|---|
Data Source |
BMS internal SoH calculation according to manufacturer logic |
Direct measurement and analysis via vehicle sensors of up to ~1,000 signals at cellular level, including big data comparison |
Standardization |
No uniform SOH standard, varies by manufacturer |
Standardized, reproducible procedure for all makes and models |
Depth of Analysis |
System level, usually an SoH value, hardly any diagnostics |
Cell-level analysis, balancing, anomaly and error detection, benchmarking vs. fleet database |
Independence |
Manufacturer-dependent, partially integrated into vehicle ECUs |
Manufacturer-neutral, independent platform and algorithms |
Tamper Resistance |
Potential for software resets, updates, "adjusted" SoH values |
Correction of distorted BMS values through independent analysis, certified processes |
Result |
Display in the tester or vehicle display |
Detailed AVILOO Battery Certificate with heat maps, flags (e.g., red/yellow), and benchmarks |
Time Required |
Short, but with limited significance |
Approximately 3 minutes, without a test drive – with a reliable indepentent diagnosis |
The Cell Level Makes the Difference
In the Readout Alone, Much Remains
Invisible
A traction battery consists of hundreds to thousands of cells. Individual cells can malfunction, overheat, degrade faster, or be poorly balanced—long before the overall SoH drops dramatically.
The AVILOO FLASH Test Detects, Among Other Things:
Degradation patterns
in certain cell groups
Balancing issues,
which indicate uneven loads
Data anomalies,
which indicate defects such as self-discharge of individual cells
Unusual temperature or voltage curves,
which are not shown in the BMS SoH
READ-OUTS ALONE ARE
BATTERY BLIND FLIGHTS
WITH A DISPLAY
The sooner these patterns are recognized, the better risks can be assessed, prices set, and warranty decisions made.
Risks for Business
- Misvaluation of residual values and returns
- Higher risk of complaints and warranty claims
- Uncertainty in buy-back programs and calculation models
- Lack of comparability between brands and models
Risks for Individuals
- Risk of purchasing a vehicle with a problematic battery
- Expensive surprises due to unexpected range loss
- Weak negotiating position without objective evidence
- Loss of trust when ads do not match lived experience
AVILOO THE STANDARD FOR
INDEPENDENT BATTERY DIAGNOSIS
AVILOO eliminates risks with independent, tamper-proof battery diagnostics for BEVs and PHEVs.
Independent & certified
AVILOO works independently of manufacturers and complies with recognized standards and certifications (e.g., ISO 9001, CE, ECE-RIO).
Accepted by the industry
AVILOO Tests and Certificates are used and recognized by leading OEMs, major leasing companies, dealers, and remarketing players.
Data competence instead of gut feeling
The evaluation is based on a broad real-world database and AI-supported models — not on individual snapshots.
The Right Solution
For Your Case
AVILOO FLASH Test
For Business
The ultra-fast battery test for workshops, dealers, remarketing, leasing, fleets, and OEMs—with a fully digitized process and API integration.
- Independent battery diagnosis at cellular level in approx. 3 minutes
- Plug-and-play hardware, DoIP compatible, no test drive required
- Up to ~1,000 signals, AI-powered analysis, benchmarking
- Certificate and "AVILOO Certified" seal as a standard of trust
*Exclusively for business customers
Do You Still Have Any
Questions?
Some questions come up again and again. If you cannot find your answer, we will be happy to assist you personally:
During a readout, tests only display values calculated by the manufacturer from the BMS, such as the SoH. These values follow the respective OEM logic and are not standardized. Independent diagnostics measure the actual behavior of the battery at cellular level and evaluate it according to a clearly defined, manufacturer-neutral procedure. The result is an objective diagnosis instead of a simple display.
SoH values provide a rough guide, but do not show how individual cell groups are really performing. Many problems remain invisible because the value is greatly simplified. An independent diagnosis reveals these hidden patterns and provides a reliable basis for decision-making.
Every OEM uses its own algorithms, thresholds and calculation logic. An identical percentage value can mean something completely different depending on the manufacturer. Independent diagnostics use a uniform methodology that makes results comparable across brands and models.
You may misjudge residual values or purchase or sell vehicles with hidden battery problems. This can result in complaints, warranty costs, or poor purchasing decisions. A readout only shows the surface. The real risk lies beneath.
Yes. An independent diagnosis evaluates hundreds to thousands of signals and examines the battery cell by cell. Weak cell groups, balancing problems, or unusual patterns in charging behavior become visible, even though the SoH value may appear to be normal.
AVILOO uses its own standardized testing methods and does not rely on the manufacturer's SoH calculation. The assessment is based on measurement data taken directly from the battery and a large EV battery database. The result is an independent, comprehensible diagnosis.
The FLASH Test takes about three minutes and is performed while stationary. Up to around 1,000 signals are recorded and evaluated. You will then receive a certificate that clearly explains the condition of the battery.
The test is passive and does not drain the battery. Data is only measured and analyzed. The evaluation runs on a tamper-proof, independent platform and cannot be altered by software resets or manual intervention.
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