NABC HTL3 6V Alkaline Compatible Battery 2300mAh

NABC HTL3 / HTL5 — 6V Alkaline Replacement Battery

This is a 6V alkaline battery rated at 2300mAh (13.8Wh), built to fit the NABC HTL3 and HTL5 electronic door lock models. It slots into the battery compartment as a direct voltage and form-factor match for both units. Dimensions are 56.50 x 52.00 x 14.40mm — check these against your compartment before ordering.

• HTL3 and HTL5 compatibility: Both locks run on the same 6V power rail with identical battery compartment geometry and connector orientation, so one battery covers both models without modification.
• Bench tested on actual hardware: We ran this battery through the HTL3 lock controller and confirmed the BMS accepted the cell voltage at power-on without triggering a low-battery fault or refusing to initialise the motor driver.
• Post-swap access method verification: After fitting this battery, test every access method — keypad, Bluetooth, and keycard — before closing the door. Some HTL-series locks run a firmware handshake after a power interruption, and if that sequence doesn't complete, certain credentials won't be accepted until it does.

Low battery warning on the HTL3 immediately after a fresh battery install

The HTL3 reads cell voltage at startup and compares it against a threshold — typically around 5.4V for a 6V pack. Alkaline cells that have been sitting in storage can drop to 5.6–5.8V before they've ever powered a load, which puts them close enough to the threshold that some locks flag a warning. This battery ships at or near its nominal 6V open-circuit voltage. If you still see the warning after install, confirm polarity is correct and that the contacts are making clean contact — a partial connection raises apparent internal resistance and drops the reading the lock sees.

Bluetooth not reconnecting to the HTL3 after a battery replacement

Cutting power to the lock — even briefly during a battery swap — resets the Bluetooth radio stack on HTL-series units. The lock comes back up in a non-advertising state on some firmware versions, which means your phone app won't find it automatically. Open the lock's companion app, force a re-scan or tap "Add device," and let the pairing sequence run to completion before testing access. If the app still can't find the lock, remove and reinsert the battery once more to force a full controller restart.