Motorola Moto P30 JK30 Replacement Battery 3.8V 2900mAh

Motorola Moto P30 — 3.8V Li-Polymer Replacement Battery (JK30)

This is a 3.8V, 2900mAh lithium-polymer replacement battery for the Motorola Moto P30 smartphone. It carries OEM part number JK30 and matches the original cell's dimensions at 82.40 × 64.60 × 3.20mm. It fits the P30 chassis connector directly with no modification.

• Moto P30 platform fit: The P30 uses a single-cell Li-Polymer pack with a 3.8V nominal rail tied directly to the PMIC. Any replacement must match that voltage and the BMS communication protocol on the flex connector — this cell does both.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the P30, verified BMS handshake at the connector, confirmed the charge IC accepted the cell without triggering a fault flag, and checked thermal behaviour across a full charge cycle.
• First-cycle fast-charge hold-off: After installation, disable fast charging for one complete discharge-to-charge cycle. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current charging pushes current into an uncalibrated coulomb counter.

Why the Moto P30 reports wrong battery percentage after a cell swap

The P30's fuel gauge IC builds its charge estimate from a learned discharge curve stored for the old cell. When you install a new cell, that stored curve no longer matches the new cell's actual voltage-versus-capacity profile. The gauge reads an old reference against a new reality, so the percentage shown can be 10–20 points off. One full discharge down to auto-shutdown followed by a full charge resets the coulomb counter and forces the IC to begin re-mapping the new cell's curve.

Sudden shutdown at 20–30% on the replacement cell

A new cell at rest can hold 3.7V at 25% state of charge, but under modem transmit or display brightness peaks, the internal resistance causes a voltage sag that briefly drops below the PMIC's cutoff threshold — typically 3.4V on the P30's protection circuit. The phone reads this as a dead cell and shuts down even though resting voltage recovers immediately. This is most common in the first five cycles before the cell's impedance settles. Run two or three full charge-discharge cycles and check that resting voltage at 20% reads above 3.55V before ruling out a faulty cell.