PBR-315 Pantech PN-315 Replacement Battery 3.7V 800mAh

Pantech PN-315 — 3.7V Li-ion Replacement Battery (PBR-315)

This is a 3.7V, 800mAh Li-ion battery for the Pantech PN-315 smartphone. It replaces OEM part number PBR-315 and fits directly into the PN-315 handset. Use it when the original cell has degraded past the point of holding a usable charge through a normal day of calls and messaging.

• PN-315 fit confirmation: The PN-315 uses a fixed 3.7V single-cell Li-ion configuration with a proprietary contact layout. This cell matches that voltage rail and connector pinout — no modification needed to seat it correctly.
• Bench tested on actual hardware: We ran this cell through the PN-315 charge IC and confirmed the BMS handshake completed without fault flags. The charge cycle accepted current normally from zero to full without interruption or thermal cutoff events.
• Fuel gauge recalibration on first use: After installing this cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. This lets the PN-315 fuel gauge IC map its coulomb counter to the new cell's actual discharge curve and stop reporting inaccurate percentages.

Why the PN-315 reports wrong battery percentage after a cell swap

The PN-315 uses a fuel gauge IC that learns the discharge curve of the installed cell over time. When you swap in a new cell, the IC is still calibrated to the old cell's internal resistance profile. This mismatch causes the reported percentage to diverge from actual state of charge — sometimes by 15–20%. One complete discharge-charge cycle resets the coulomb counter reference and brings the display reading back into alignment.

Sudden shutdown at 20–30% on the replacement cell

This happens when the phone's processor, modem radio, or screen draw a current spike the cell cannot sustain without voltage sagging below the BMS cutoff threshold. The display shows 25% remaining, but under load the cell voltage drops sharply — the BMS trips and the phone cuts out instantly. It is not a faulty battery. Charge to 100%, complete one full discharge cycle, and check that the shutdown threshold rises above the 3.0V floor the BMS uses to protect the cell.