Explay X-Tremer 3.7V Replacement Battery 2000mAh Li-ion

Explay X-Tremer — 3.7V Li-ion 2000mAh Replacement Battery

This is a 3.7V, 2000mAh Li-ion replacement battery for the Explay X-Tremer smartphone. It slots into the X-Tremer's battery bay and restores full power when the original cell has degraded or failed. Dimensions are 70.00 × 59.90 × 4.40mm — measure your existing cell before ordering if you are unsure.

• X-Tremer fit: The X-Tremer runs a standard removable bay with direct contact terminals. This cell matches the voltage rail and physical footprint that the phone's charge IC and BMS expect — no adapter or modification needed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS held the cutoff correctly at both ends, and the charge IC accepted the cell without error flags on subsequent cycles.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build an accurate discharge curve for the new cell before high-current charging is applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the X-Tremer after a cell swap

This happens when the new cell hits a voltage cliff under load — the modem transmitting or the screen at full brightness pulls enough current to drop cell voltage below the BMS cutoff threshold, even though the fuel gauge still shows charge remaining. The fuel gauge IC is still calibrated to the old cell's discharge curve, so its percentage reading and the cell's actual voltage under load fall out of sync. Run one full discharge to 1–2% and a full uninterrupted charge to 100% without using the phone heavily. After that cycle, the coulomb counter resets its reference and shutdowns at 20–30% typically stop.

OS reporting wrong battery percentage after replacement

Android's fuel gauge IC stores a learned discharge curve from the previous cell. When a new cell goes in, that stored curve no longer matches the actual cell chemistry and impedance — so the percentage shown can jump, stall, or read 100% when the cell is not fully charged. The fix is one complete uninterrupted discharge down to automatic shutdown, followed by a full charge to 100% with the phone off or idle. After this single calibration cycle, percentage accuracy returns to normal. If jumping persists after two cycles, check that the battery contacts are fully seated.