Ezviz VOC Smart Lock Replacement Battery 7.5V 5000mAh

Ezviz VOC Smart Door Lock — 7.5V Li-ion Replacement Battery (BL3601)

This 7.5V 5000mAh (37.5Wh) lithium-ion battery replaces the internal pack in the Ezviz VOC smart door lock. It powers the motorised bolt, keypad, Bluetooth module, and wireless connectivity functions. Compatible OEM part numbers include BL3601, BL3602, BL3603, PB3601, PB3602, and PB3603.

• VOC platform compatibility: The VOC series shares a single internal battery form factor across its lock variants. The BMS on this pack communicates at 7.5V to keep the motor driver, keypad backlight, and RF module on separate regulated rails — a mismatch in voltage or connector pinout causes the lock to report a fault before the bolt cycles.
• Bench tested on actual hardware: We ran this pack through full charge and multiple bolt-cycle draws on a VOC lock body. The BMS held voltage stable under motor-start surge and did not trigger an overcurrent cutoff during repeated lock and unlock sequences.
• Post-swap access method verification: After fitting this battery, test every access method — keypad PIN, Bluetooth app, and keycard — before closing the door. The VOC performs a firmware handshake on power restoration, and some access credentials will not be accepted until that sequence completes.

Bluetooth not connecting to the VOC after battery replacement

When power is interrupted during a battery swap, the VOC's Bluetooth module resets its pairing state on some firmware versions. The lock reinitialises its radio stack on first boot, which can cause the Ezviz app to show the lock as offline or unresponsive even with a fully charged battery installed. Force-close the Ezviz app, then reopen it and navigate to the device — the app will re-establish the Bluetooth session without a full re-pair on most units. If the lock still appears offline, hold the lock's reset button for three seconds to restart the radio module without clearing access codes.

VOC keypad unresponsive immediately after fitting a new battery

This happens when the BMS on the new pack enters protection mode during installation — usually caused by a brief short at the connector terminals. The keypad and motor receive no power, and the lock appears completely dead. Remove the battery, wait 10 seconds, then reinsert it firmly. The BMS resets on reconnection and the pack should read above 7.2V at the terminals before reinsertion — below that, the lock's controller will not boot the keypad.