Battery health certificates
for used EVs.
BattGrade is an app for EV inspectors, dealers and fleet teams. Plug a supported OBD2 adapter into the car, read the high voltage battery in a few minutes, and send your customer a signed PDF certificate that anyone can verify at battgrade.com.
From plug in to signed certificate
in four steps.
You need a phone, the BattGrade app and a supported Bluetooth OBD2 adapter. Nothing is written to the car.
Read the methodologyConnect
Plug a supported Bluetooth OBD2 adapter into the car's diagnostic port and pair it with the BattGrade app: the OBDLink MX+ on Android, or a Bluetooth LE adapter such as the OBDLink CX on iPhone.
OBDLink MX+ · pairedRead
The app identifies the car from its VIN and reads the battery management system with read-only requests: cell voltages, temperatures, capacity or energy, and the State of Health (SoH) the car itself reports. Nothing is written to the car.
Reading cell voltages · 64%Score
BattGrade's server recomputes the result from the raw data. You get an SoH percentage with the method used and an uncertainty band, a grade from A to F on the same scale for every make, and warnings such as uneven cells.
SoH 91.3% · ±6 pointsDeliver
Enter your customer's name and email. They receive a signed PDF certificate with a QR code that anyone can check at battgrade.com/verify. Each certificate is valid for 6 months.
PKS-2026-EU-00012345Built for the people who move the EV market.
One app and one certificate, used in four ways.
What's inside every BattGrade certificate.
A PDF that records the condition of the high voltage battery on the day of the test: the State of Health, how it was obtained and how precise it is, the grade, any warning signs and who ran the test.
Method and uncertainty
The SoH comes with the method behind it (energy-based, capacity-based or BMS-reported) and an uncertainty band in points.
Checks
Cell voltage spread, temperature spread, insulation and signs of a BMS reset, wherever the car provides the data.
QR verification
Every certificate carries a unique QR code that opens its live, public record on battgrade.com.
Digital signature
Signed with an ECDSA P-256 key over a hash of its data, and stamped with the algorithm version used to score it.
6-month validity
Time-bound by design, so a certificate always reflects a recent reading.
Why you can trust the number.
A grade only helps if nobody can bend it. This is how BattGrade keeps it honest.
Recomputed on our server
The app sends the raw data with every test. Our server decodes and scores it again, and only its result goes on the certificate. Nobody can type or edit the score.
Signed and verifiable
Every certificate is digitally signed. The verification page checks the signature each time it opens, and our public keys are published.
Method and uncertainty shown
The certificate names how the SoH was obtained and how precise it is, in points either side of the score.
Read-only requests
The app only reads. It never writes to the car, clears fault codes or resets a control unit.
The inspector is named
The certificate shows who ran the test, with their company logo if they choose. BattGrade is not a public authority and not an accredited test lab.
No special hardware
No proprietary box to buy. The app works with supported Bluetooth OBD2 adapters such as the OBDLink MX+ and the OBDLink CX.
Ready to issue your first certificate?
Get early access to the app, or book a 20-minute call where we walk you through a real test and certificate.