BL-5H Microsoft Lumia 630 Replacement Battery 3.7V 1650mAh

Microsoft Lumia 630 / 636 / 638 — 3.7V Li-ion Replacement Battery (BL-5H)

This is a 3.7V 1650mAh Li-ion replacement for the BL-5H battery. It fits the Microsoft Lumia 630, Lumia 630 Dual SIM, Lumia 636, and Lumia 638. If your original cell is swelling, no longer charging, or dropping out under load, this is a direct swap for the OEM part.

• Lumia 630 / 636 / 638 platform fit: These four models share the same battery bay dimensions, 3.7V rail, and BL-5H connector pinout. The BMS handshake protocol is identical across the series, so one cell covers the full range.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on a Lumia 630. The BMS accepted the charge handshake on the first cycle, voltage held stable at 3.7V nominal, and no thermal events occurred during a full charge sequence.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging for the first complete discharge-charge cycle. This lets the phone's fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the Lumia 630 after a cell swap

This happens because the fuel gauge IC still holds the discharge curve from the old, degraded cell. When the new cell hits a voltage point the IC associates with a low-battery cutoff on the old curve, it triggers a shutdown — even though actual capacity remains. The fix is one full uninterrupted discharge down to automatic shutdown, followed by a complete charge to 100% without interruption. After that single cycle, the IC recalibrates its curve to the new cell and percentage readings stabilise.

Phone warm near the battery compartment during first charge

A new Li-ion cell has higher internal impedance than a broken-in cell. During the first few charge cycles, the charge IC pushes current into that higher-impedance cell, and some energy converts to heat rather than stored charge. This is normal and reduces after two to three cycles as the cell's impedance settles. If the device feels hot rather than warm, or if warmth persists beyond the third charge cycle, check that the replacement cell is seated flat with no gap between the cell and the battery contacts — a misaligned cell raises contact resistance and compounds the heating.