01 / Diagnostics
Data integrity & anomalies
Check units, timestamps, sensor consistency and counter behavior before treating an anomaly as a battery or system fault. Identify which signals are usable and what needs verification.
Independent battery & BESS engineering
Turning field data into engineering decisions.
Independent battery energy storage system (BESS) diagnostics and performance analysis—connecting data quality, operating context and health trends to the next engineering step.
What I work on
Separate the signal from the assumption.
02 / Performance
Operation & system limits
Read battery, converter and supervisory-control signals together. Compare commanded and delivered behavior to investigate dispatch changes, operating limits and potential equipment constraints.
03 / Degradation
Health trends in context
Assess state-of-health (SOH) evidence and change relative to a documented baseline. Account for temperature, load and measurement history rather than treating a single value as the whole diagnosis.
Decision relevance. Prioritize investigation and maintenance, and clarify the technical assumptions behind asset valuation and insurance risk review. The role is evidence-based technical due diligence—not asset pricing or underwriting.
How I work
“Before deciding what is wrong, determine whether the data supports the conclusion.”
- Data
- Context
- Analysis
- Engineering Decision
I first examine signal quality and comparison conditions, then interpret persistent changes and remaining uncertainty. A baseline-relative trend adds context; it does not automatically remove bias or operating-condition differences.
The output: a clear account of what is supported, what remains unresolved and which measurements or checks should come next.
Selected public work
From laboratory cells to operating systems.
Public-data case studies connecting observations, engineering interpretation and decision limits. Start with Case-003 for operating BESS telemetry.
Case-003 · Operating BESS telemetry
Can the BMS Data Be Trusted?
M5BAT Pb1 / Exide1 · Flooded lead-acid storage · Public operating data
Less throughput does not, by itself, prove less capacity. The audit separates telemetry defects, recorded command changes and a remaining battery-health concern.
A separately filtered field-resistance indicator increased, but neither that signal nor the energy decline establishes a direct percentage of capacity loss or a unique root cause.
- Observed absolute
AC throughput - −78.0%
- Recorded absolute
command energy - −77.4%
2022 → 2024, analyzed records. These are energy changes, not capacity-loss estimates; the cause of lower commands remains unresolved.
Case-001 · Laboratory lithium-ion cell
When SOH Looks Wrong
NASA PCoE B0005
Capacity rises briefly within an overall declining trend. Check measurement history and persistence before calling it recovery; the observations do not establish a single physical cause.
Case-002 · Laboratory lithium-ion cells
Why Single-Point SOH Is Questioned in the Field
NASA PCoE B0005 / B0006 / B0007 / B0018
Voltage rebound varies across cells, rest times and the aging sequence. Compare baselines and conditions before inferring degradation; neither rebound nor a smoother trend establishes ground-truth SOH.
These are independent public-data studies, not client project outcomes, verified site recoveries or quantified financial savings. Methods, data coverage and reproducibility are case-specific; the studies do not establish a universal SOH model or transferable thresholds across chemistries.
About the practice
Anthony Chou, Ph.D.
Battery & Energy Systems Consultant
BESS Diagnostics is my independent consulting practice, focused on system-level BESS analysis and integration. The work is supported by hands-on battery and system testing up to approximately 500 kW.
Based in Houston, Texas. Typically working remotely, with site or vendor calls when needed.
Start a conversation
What decision does your data need to support?
Share the symptom, the operating context and the decision at hand. A focused first conversation can clarify the evidence needed for the next engineering step.
anthony@bessdiag.comPlease keep initial inquiries non-confidential.