Cricket Grand X Max 2 Replacement Battery 3.85V 3400mAh

Cricket Grand X Max 2 — 3.85V Li-Polymer Replacement Battery

This is a 3.85V, 3400mAh (13.09Wh) Li-Polymer battery for the Cricket Grand X Max 2 smartphone. It replaces the original cell when the phone no longer holds a full charge, shuts down unexpectedly, or fails to power on after extended use. No OEM part number is published for this cell; fitment is confirmed by physical dimensions (86.00 × 66.30 × 4.10 mm) and connector position.

• Grand X Max 2 fitment: The Grand X Max 2 uses a sealed unibody back panel with a single flat Li-Polymer cell at this exact footprint. The connector tab aligns to the logic board's ZIF socket without modification. Any deviation in cell thickness causes housing stress — this cell measures 4.10 mm, matching the original cavity depth.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the Grand X Max 2 mainboard. The charge IC accepted the cell without fault codes, BMS handshake completed on first connection, and voltage held stable under simultaneous display and modem load.
• Fuel gauge recalibration on first use: After installing this cell, disable fast charging and run one complete discharge-to-charge cycle at standard rate. The Grand X Max 2 fuel gauge IC is calibrated to the original cell's discharge curve — a single slow cycle lets it remap against the new cell before high-current charging begins.

Sudden shutdown at 20–30% on the Grand X Max 2 after cell replacement

This happens because the fuel gauge IC still uses the old cell's voltage-to-capacity curve. The new cell hits a voltage cliff — where voltage drops sharply under modem or screen load — at a point the gauge still reads as 20–30%. The phone interprets that voltage drop as a fault and shuts down to protect the board. One full slow discharge cycle forces the coulomb counter to relearn the new cell's actual curve, and the shutdowns stop.

Phone shows wrong battery percentage after the swap

The Grand X Max 2 tracks charge state using a fuel gauge IC that accumulated data on the original cell over months of use. Swapping the cell doesn't reset that learned data automatically. The gauge reports percentage against the old cell's internal resistance profile, so readings drift — sometimes jumping 10–15% in either direction. Power the phone down, charge it to 100% at standard rate without interruption, then drain it fully to 0% and let it auto-shutdown. After one complete cycle, the fuel gauge recalibrates and percentage accuracy returns.