Philips BL3601 Smart Lock Replacement Battery 7.5V 5000mAh

Philips 301-FVP / 708-FVP Series — 7.5V Li-ion Replacement Battery (BL3601)

This is a 7.5V, 5000mAh Li-ion replacement battery for Philips electronic smart door locks. It fits the 301-FVP, 708-VP, 708-FVP, 709-FVP, and over a dozen additional models in the same series. The BL3601 / BL3602 / BL3603 and PB3601 / PB3602 / PB3603 OEM part numbers all cross to this unit.

• 301-FVP and 708/709-FVP platform fit: These models share the same battery bay geometry, 7.5V power rail, and BMS handshake protocol. The lock's motor driver and keypad controller both draw from a single cell pack — a voltage mismatch here causes the lock to refuse operation entirely, not just warn low.
• Bench tested on actual hardware: We cycled this battery through the lock's full wake sequence — motor actuation, keypad polling, and Bluetooth radio activation. The BMS held the output steady across all three loads without tripping the overcurrent cutoff on motor start.
• Post-install access method check: After fitting this battery, test every access method — keypad, Bluetooth app, and keycard — before closing the door. The 301-FVP runs a firmware handshake on first power-up after battery interruption. If that sequence does not complete, the lock may accept the motor command but reject credential input until it finishes.

Why the 708-FVP shows low battery immediately after a new pack is fitted

The 708-FVP reads cell voltage at startup, not capacity. If the replacement battery has been sitting in storage, its resting voltage may have dropped below the lock's warning threshold — typically around 7.0V on this platform. The lock interprets that as a depleted battery and triggers the alert before the BMS can stabilise output. Charge the battery to full before installing it, then power-cycle the lock to clear the low-battery flag.

Bluetooth app not connecting after battery swap on the 301-FVP

Cutting power to the 301-FVP resets the Bluetooth module's pairing state on some firmware versions. The lock radio comes back up in a restricted mode and will not complete a connection handshake with a previously paired phone. Open the Philips Home Access app, remove the lock from the device list, and re-add it using the QR code or manual ID on the lock body. The motor and keypad will continue to work independently during this process — only the app link is affected.