Know what a used
battery is worth
A capacity test costs a day on a bench cycler. This platform estimates state of health from an ordinary charge cycle, tells you why the pack is degrading, checks it against its own safety limits, and issues a signed passport a buyer can verify.
90% interval 74.9–81.9% · 1.57 Ah remaining
Six answers from
one charge cycle
Each block below is produced by a separately validated component, and each is labelled with how it was obtained. A number the model inferred is never presented the same way as a number that was measured.
State of health
A capacity estimate with a calibrated 90% interval, drawn from how the charge divides between its constant-current and constant-voltage phases.
Degradation attribution
Which mechanism is taking the capacity — lithium inventory loss, resistance growth, thermal stress — and the measured signals behind each claim.
Safety envelope
A risk score with named drivers, plus derated charge current, SOC window and temperature limits computed from the pack's own format specification.
Anomaly detection
Physical rule checks, statistical outlier detection and trajectory deviation, each reported separately so silence from a detector is distinguishable from a clean result.
Second-life grade
A reuse grade on the point estimate, with the grade marked ambiguous whenever the confidence interval straddles a boundary.
Signed passport
An Ed25519-signed document carrying the assessment, the model provenance and the method labels. Alter one field and verification fails.
Four steps, in this order
The order matters, which is why these are numbered: each step determines which model the next one is allowed to use.
- 01
Charge it
Run one ordinary charge. Either log it as CSV, or read six numbers off the charger display when it finishes.
- 02
Submit what you have
There is no fixed input set. The platform picks the richest tier your data supports and uses the model trained for exactly that tier.
- 03
Read the estimate
Health, safety, anomalies and reuse grade, each with the accuracy measured for your tier — not a headline number borrowed from the best case.
- 04
Issue the passport
Sign the assessment into a portable document. A buyer verifies it against the issuer's public key without trusting you.
The number you get is the one measured for your inputs
Mean absolute error in SOH percentage points, measured by leave-one-battery-out cross-validation on four NASA cells. Each tier has its own separately trained and separately validated model, so a missing input never becomes a silent null in a model that never saw one.
| Tier | What you supply | MAE | R² | Output |
|---|---|---|---|---|
Tier 1 Telemetry + impedance | Full charge curve plus EIS values | 2.67 pts | 0.867 | Full report |
Tier 2 Telemetry | Full charge curve, no impedance | 2.75 pts | 0.858 | Full report |
Tier 3 Charge summary | Six hand-typed numbers | 2.86 pts | 0.845 | Full report |
Tier 4 Minimal | Charge phase split only | 5.58 pts | 0.127 | Indicative |
A claim a buyer can check without trusting the seller
The passport is a JSON document signed with an Ed25519 key. It carries the health estimate, the confidence interval, the model provenance hash and an explicit label saying the figure was estimated rather than measured. Change the SOH from 78% to 97% and the signature stops verifying — which you can demonstrate from the dashboard in one click.
- Ed25519 detached signature over a canonical serialisation
- Method labels travel with the numbers, so an estimate can never be read as a test result
- Model version, training-data hash and validation method embedded in the payload
- Verify against a published key, or paste the document into any Ed25519 verifier
- A QR code provides instant access to the battery passport for quick verification and lifecycle tracking
{
"payload": {
"battery": { "battery_id": "B0005" },
"health_estimate": {
"soh_percent": 78.4,
"confidence_interval_90": [0.749, 0.819],
"method": "ESTIMATED"
},
"second_life_assessment": {
"grade": "B",
"grade_confidence": "MEDIUM"
},
"certified_test_status": "NOT_PERFORMED"
},
"signature": {
"algorithm": "Ed25519",
"value": "9f2c…a71b"
}
}Change soh_percent to 97.5 and the signature stops verifying. You can do exactly that from the dashboard.
The assessment doesn't end with a number
BATRIS turns the result of a battery assessment into a portable, verifiable record — one that can be shared, checked and carried forward with the battery.
Point it at a battery
Four NASA cells are loaded and ready to assess. Or bring your own charge log and see what your level of information actually buys you.