HLXU02 Bell & Howell BH725 Replacement Battery 3.7V 1000mAh

Bell & Howell BH725 — 3.7V Li-ion Replacement Battery (HLXU02)

This 3.7V Li-ion cell replaces the original battery in the Bell & Howell BH725 smartphone. It runs at 1000mAh (3.7Wh) and uses OEM part number HLXU02. If your BH725 shuts down unexpectedly, drains fast, or won't hold a charge, this is the direct swap.

• BH725 fit: The BH725 uses a fixed connector and BMS handshake tied to this specific cell footprint — 52.95 x 33.07 x 8.01mm. The HLXU02 matches that footprint exactly, so the charge IC reads the new cell without throwing a fault code.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the BH725 platform. The BMS accepted the cell on the first cycle, charge termination triggered correctly at full voltage, and no thermal flags appeared during the charge phase.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one full discharge-charge cycle before enabling it again. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.

Sudden shutdown at 20–30% on the BH725 after a cell swap

The BH725's fuel gauge IC was calibrated to the original cell's discharge curve. When a new cell goes in, the IC doesn't yet know where the new cell's voltage cliff sits. Under modem or display load, the cell voltage can drop faster than the IC predicts, triggering an emergency shutdown before the reported percentage reaches zero. Running one full uninterrupted discharge down to automatic shutdown — then a full charge — gives the coulomb counter enough data to reset its model. After that cycle, reported percentage and actual cell voltage align properly.

BH725 not powering on after the battery sat in storage

Li-ion cells that drop below roughly 2.5V trigger a BMS lockout to prevent unsafe recovery charging. If the BH725 sat for months with a depleted cell, the BMS may refuse to pass current to the phone at all — the device appears completely dead. Connect the phone to a wall charger rated at 5V and leave it for 15–20 minutes without pressing the power button. The charge IC applies a low-current pre-charge trickle to bring the cell above the BMS re-enable threshold, after which normal charging resumes. If the screen still shows nothing after 30 minutes on charge, check that the charger output is confirmed at 5V — a failing cable is a common culprit here.