LG D320 Replacement Battery BL-52UH 3.7V 1450mAh

LG D320 / MS323 Series — 3.7V Li-ion Replacement Battery (BL-52UH)

This is a 3.7V, 1450mAh Li-ion cell that replaces the original BL-52UH battery in the LG D320, MS323, D325, D329, and compatible variants. It fits the standard battery bay with no modification. Physical dimensions are 61.90 × 46.90 × 5.30mm — confirm against your existing cell before ordering.

• D320 / MS323 platform fit: These models share the same battery footprint, connector orientation, and BMS communication protocol. The BL-52UH form factor and contact arrangement are consistent across the group, so one cell covers the full compatibility list.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the D320 platform. The BMS handshake completed cleanly, charge termination triggered at the correct cutoff voltage, and protection circuits responded normally to over-current conditions.
• Fuel gauge recalibration on first use: After installing a new cell, run one complete discharge down to automatic shutoff, then charge uninterrupted to 100% before resuming normal use. The LG fuel gauge IC calibrates its coulomb counter against this first full cycle — skipping it causes percentage jumps and early shutdown warnings against a perfectly healthy cell.

Why the D320 reports wrong battery percentage after a cell swap

The LG D320 uses a fuel gauge IC that tracks charge state by counting coulombs against a stored discharge curve from the original cell. When you install a new cell, the IC still references the old curve, so the percentage reading drifts immediately. The gauge reads high early in discharge and then drops sharply as the new cell's actual voltage profile diverges from the stored model. One full discharge-to-shutoff followed by a full uninterrupted charge resets the learned curve to match the replacement cell. After that single calibration cycle, percentage readings stabilise.

Sudden shutdown at 20–30% on the new cell

This happens when the modem or display draws a current spike that drops cell voltage below the BMS protection threshold — even though the reported percentage still looks healthy. A fresh cell with an uncalibrated fuel gauge cannot accurately predict that voltage cliff, so the phone cuts out without warning. The root cause is the same gauge calibration gap described above, but high-load moments — video playback, active calls, screen at full brightness — trigger it faster. Complete one full calibration cycle first; if shutdowns continue after that, check that the replacement cell rests at 3.6V or above under no-load conditions.