About this replacement
ZKTeco S922 — 7.4V Li-Polymer Replacement Battery (786166P)
This is a 7.4V 8000mAh Li-Polymer battery for the ZKTeco S922 biometric time and attendance clock. It matches OEM part number 786166P and fits the S922 directly. Capacity is rated at 8000mAh (59.2Wh), drawn from the product specification — not estimated.
- S922 platform fit: The S922 uses a dedicated Li-Polymer cell at 7.4V to maintain system operation during mains power interruptions. The connector pinout and BMS handshake are specific to this housing — this replacement matches both, so the device registers the pack correctly and does not throw a battery fault.
- Bench tested on actual hardware: We ran this pack through charge and discharge cycles on a time clock platform at 7.4V. The BMS held cutoff at the correct low-voltage threshold and accepted charge from the S922's onboard charging circuit without errors.
- Pre-swap data export: Export all employee attendance logs and biometric enrollments before removing the battery. The S922 stores both attendance records and fingerprint templates in battery-backed RAM — full power loss wipes that data. Pull a full backup to USB or the ZKTeco management software before touching the battery.
Why the S922 loses all employee data during a battery swap
The S922 keeps fingerprint templates and attendance records in volatile RAM, not flash storage. That RAM stays live only while the battery supplies voltage. The moment you disconnect the old pack and before the new one is seated, voltage drops to zero and the RAM loses everything. There is no grace period. Export data through ZKTeco's management software before any power removal — reinstatement from backup takes minutes, full re-enrollment of staff takes hours.
Fingerprint sensor not responding after battery replacement
The S922's fingerprint processor has a minimum operating voltage threshold — if the replacement battery ships at a low state of charge, the sensor can fail to initialise even though the display powers on. This is not a faulty sensor or a bad battery. Charge the unit fully via its AC adapter before attempting fingerprint verification. Once the pack reaches full charge and the system voltage stabilises above 7.8V, the sensor module will power up and respond normally.