MyPhone Hammer Iron BM-06 Replacement Battery 3.7V 2000mAh

MyPhone Hammer Iron / H-Smart — 3.7V Li-ion Replacement Battery (BM-06)

This is a 3.7V, 2000mAh Li-ion battery for the MyPhone Hammer Iron and H-Smart smartphones. It replaces part number BM-06 when the original cell has degraded through normal charge cycles. Capacity figure comes from product data — 7.4Wh total energy.

• Hammer Iron and H-Smart compatibility: Both models share the BM-06 footprint, connector pinout, and BMS handshake protocol. Swapping between these two devices is not recommended — each phone's charge IC is calibrated to its own fuel gauge curve, so cross-fitting can cause erratic percentage reporting.
• Bench tested on actual hardware: We cycled this cell through full discharge and charge on the Hammer Iron platform. The BMS accepted charge without tripping, held voltage above 3.5V under sustained screen and modem load, and reported state-of-charge consistently after one full calibration cycle.
• First-cycle fuel gauge recalibration: After installing this cell, disable fast charging in the phone's settings for the first complete discharge-charge cycle. The fuel gauge IC needs one uninterrupted cycle at standard current to map the new cell's discharge curve before high-current charging gives it accurate data.

Sudden shutdown at 20–30% on the Hammer Iron after a cell swap

The Hammer Iron's fuel gauge IC stores a discharge curve from the old cell. When a new cell arrives with a steeper voltage drop at low state-of-charge, the phone's cutoff threshold triggers earlier than the displayed percentage suggests. The phone shuts down not because the battery is empty, but because the fuel gauge IC is reading against the wrong curve. One complete discharge to automatic shutdown — followed by a full charge without interruption — re-maps the curve and brings the reported percentage back in line with real cell voltage.

Phone feels warm near the battery during the first few charges

A fresh Li-ion cell has higher internal impedance than a broken-in one. The Hammer Iron's charge IC pushes current into that higher-resistance cell, generating more heat than normal at the contact points. This is a temporary condition — internal impedance drops after two to three full cycles as the electrolyte settles. If the phone remains warm past the third charge cycle, check that the back cover is seated correctly and not trapping heat against the battery.