About this replacement
Saflok 20280 — 6V Li-MnO2 Replacement Battery (DL-9)
This is a 6V, 1300mAh lithium-manganese dioxide battery for the Saflok 20280 electronic door lock. It replaces OEM part number DL-9 and powers the lock's keypad, motor, and access control electronics. Dimensions are 35.40 × 33.30 × 16.70mm — verify fitment before ordering.
- Saflok 20280 compatibility: The 20280 lock series requires a 6V Li-MnO2 cell to meet the voltage threshold for the control board and latch motor. A lower-voltage chemistry will cause intermittent operation or prevent the lock from cycling at all.
- Bench tested on actual hardware: We ran this cell through full lock cycles and confirmed the BMS holds voltage steady across motor engagement. No sag or cutoff was triggered during normal latch operation.
- Post-swap access method check: After fitting the new battery, test keypad, keycard, and any Bluetooth or RFID access before closing the door. The 20280 may require a brief power-on handshake to recognise all credential types after a full power interruption.
Low battery warning on the Saflok 20280 immediately after a fresh install
Li-MnO2 cells can sit in warehouse stock for extended periods, and some arrive below the voltage threshold the 20280 uses to confirm a healthy battery. The lock's controller reads open-circuit voltage on startup — if the cell is below roughly 5.8V, the warning triggers regardless of rated capacity. This is not a fault in the lock. Check the cell voltage with a multimeter before installing; a fresh DL-9 should read 6.0–6.4V at rest.
Saflok 20280 not responding after battery replacement
When power is fully interrupted during a swap, the 20280's control board can enter a low-power standby state that does not self-recover on battery insertion alone. The fix is a deliberate power cycle: remove the new battery, wait 30 seconds for capacitors to drain, then reinsert. If the lock still does not respond, confirm polarity is correct and that the cell voltage reads at least 6.0V before re-seating.