NTT DoCoMo HT1100 NIKI160 Compatible Battery 3.7V 1200mAh

NTT DoCoMo HT1100 — 3.7V Li-Polymer Replacement Battery (NIKI160)

This is a 3.7V, 1200mAh Li-Polymer battery for the NTT DoCoMo HT1100 smartphone. It replaces part number NIKI160 and fits the original battery compartment without modification. Capacity is 4.44Wh — matching the stock specification from the original hardware.

• HT1100 fitment: The HT1100 uses a compact Li-Polymer cell with a specific connector orientation and BMS pinout tied to NTT DoCoMo's charge IC. This replacement uses the same NIKI160 form factor — same dimensions at 44.36 × 46.50 × 6.38mm — so the BMS handshake with the charge controller completes correctly.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a controlled test rig, confirming the BMS protection trips at the correct low-voltage cutoff and that the cell accepts a full charge without thermal event or premature termination.
• Fuel gauge recalibration on first use: After fitting this replacement, run one complete discharge-to-charge cycle with fast charging disabled if your charger supports it. The HT1100's fuel gauge IC was calibrated to the old cell's discharge curve — one full cycle against the new cell resets the coulomb counter baseline and stops percentage readings from drifting.

Why the HT1100 shuts down suddenly at 20–30% battery remaining

This is a voltage cliff failure. The original aged cell can no longer hold its voltage under load from the modem radio or display backlight, so it drops below the BMS cutoff threshold — even though the fuel gauge still reads 20–30%. The replacement cell has a healthier internal resistance, so it sustains voltage under that same load. After one full recalibration cycle, the percentage reading will align more accurately with actual remaining capacity.

Phone shows incorrect battery percentage after fitting the replacement cell

The fuel gauge IC stores a learned discharge curve from the old cell. When a new cell is fitted, the stored curve no longer matches actual cell behaviour, so percentage readings jump or read high and drop fast. This is not a fault with the replacement — it is the coulomb counter working from stale calibration data. Discharge the phone fully until it powers off, then charge it uninterrupted to 100% to force the fuel gauge to recalculate against the new cell. After that cycle, readings stabilise.