Battery Pack Aadhaar Anchored in the BMS: Hardware-Signed, Hash-Chained Health Records for Indian Two- and Three-Wheeler Packs Without a Blockchain

India's draft Battery Pack Aadhaar guidelines ask for a tamper-proof dynamic record of every traction battery, including state of health, yet leave that record to be uploaded by producers and service providers. Most published battery passport designs answer the integrity question with a blockchain. A ledger, however, protects data only after it has been written; it cannot show that a state-of-health figure was ever measured by the pack it describes. This paper moves the root of trust into the battery management system. A secure element inside the pack holds a non-exportable signing key bound to the pack identifier at end of line and a monotonic counter that numbers every daily health record. Records are hash-chained and signed, a fresh-nonce attestation exposes rollback, and a government registry stores chain heads in a witnessed Merkle transparency log. The scheme was implemented with standard elliptic-curve signatures and evaluated on 4000 simulated Indian two- and three-wheeler packs over six years under four duty cycles. Every cryptographic tampering attempt in the test suite was rejected with no false alarms on honest logs. Rollback of an exported log file went undetected unless the verifier challenged the live pack or held a registry anchor, a limitation we report rather than design around. A physics-based screen on the signed stress history detected state-of-health inflation with ninety percent probability once it exceeded about five to fourteen percentage points, depending on duty cycle and age, at a one percent false-alarm rate, but could not catch an attacker who controls the firmware and falsifies the stress counters consistently. Storage stays near 520 KiB for ten years of daily records. Because every log has exactly one writer, ordering needs no consensus, and a witnessed log gives the same tamper evidence without tokens, gas or wallets.