Globul Z3 Replacement Battery 3.7V 1300mAh Li-ion

Globul Z3 — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1300mAh Li-ion replacement battery for the Globul Z3 smartphone. It slots directly into the Z3 and restores power to the device when the original cell has degraded or failed. Capacity is rated at 4.81Wh.

• Z3 platform fit: The Z3 uses a compact single-cell Li-ion pack at 3.7V nominal. This replacement matches the original cell's voltage rail and connector orientation, so the phone's charge IC and BMS handshake correctly from first boot.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the bench. The BMS held cutoff voltage cleanly at the low end, and the charge IC accepted standard current without rejecting the session or triggering a fault flag.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle. The fuel gauge IC in the Z3 is calibrated to the old cell's discharge curve — giving it one full uninterrupted cycle lets it remap against the new cell before you stress it with high-current input.

Sudden shutdown at 20–30% on the replacement cell

A fresh Li-ion cell has a slightly different discharge curve than the aged cell it replaced. The Z3's fuel gauge IC still holds the old cell's voltage-to-capacity map in memory. When the new cell hits a voltage point the IC associates with near-empty, it trips a shutdown even though real capacity remains. This is not a faulty battery — it is a calibration mismatch. Run one full discharge to auto-off followed by a full charge uninterrupted, and the IC rewrites its curve. After that cycle, shutdowns at 20–30% stop.

Phone feels warm near the battery during the first few charges

A new Li-ion cell starts with higher internal impedance than a broken-in cell. The Z3's charge IC pushes current into that higher impedance, generating more heat than normal during the first two or three charge sessions. This is expected and settles as the cell completes its initial formation cycles. If warmth persists past the third full charge, check that the back cover is seated fully — trapped heat with no airpath keeps temperatures elevated. After three cycles, surface temperature during charging should return to normal.