Explay MU220 Replacement Battery 3.7V 1050mAh

Explay MU220 / SL240 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1050mAh Li-ion cell replacing the original battery in the Explay MU220 and SL240 smartphones. It fits the same physical cavity and connector as the factory cell. Dimensions are 53.00 × 33.90 × 5.60mm — measure your original before ordering if you are unsure.

• MU220 and SL240 shared platform: Both models run the same 3.7V single-cell architecture with an identical connector footprint and cell bay dimensions. One cell fits both because Explay used a common battery specification across this compact phone tier.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS accepted the charge IC handshake without error, and protection thresholds — overvoltage, undervoltage, and short-circuit cutoff — triggered at expected points.
• Fuel gauge recalibration on first cycle: On first use after installation, run one complete discharge down to auto-shutdown, then charge uninterrupted to 100%. The fuel gauge IC in the MU220 is calibrated to the old cell's discharge curve — this single full cycle resets it to the new cell's actual capacity profile.

Sudden shutdown at 20–30% on the Explay MU220

This is a voltage cliff failure, not a capacity issue. When the modem transmits or the screen brightness spikes, current draw pulls the cell voltage below the BMS cutoff threshold faster than the fuel gauge can track. The phone shuts down even though the percentage counter still shows charge remaining. One full discharge-charge cycle after installation corrects this — the fuel gauge IC maps the new cell's actual voltage-to-capacity curve and the early shutdowns stop.

OS showing wrong battery percentage after cell swap

After fitting a new cell, the Android fuel gauge IC is still running the coulomb counter model it built around the degraded original battery. It reports percentage against the wrong baseline, so readings jump or plateau at incorrect values. This is not a fault with the replacement cell. Charge to 100%, let the phone discharge fully to auto-shutdown, then recharge to 100% without interruption — that single cycle resets the coulomb counter to the new cell's actual charge curve.