Neo 1973 Smartphone Replacement Battery 3.7V 1200mAh

Neo 1973 — 3.7V Li-ion Replacement Battery (GTC-01/GTA-01)

This is a 3.7V 1200mAh Li-ion replacement battery for the Neo 1973 smartphone. It fits the original battery slot using OEM part references GTC-01, GTA-01, and WDM063900132. Dimensions are 53.00 × 33.90 × 5.70mm — measure your original before ordering if you are unsure.

• Neo 1973 fit: The 1973 uses a single-cell 3.7V nominal Li-ion architecture with a compact flat pack form factor. This cell matches the voltage rail and connector position the device expects, so the BMS handshake completes without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the 1973 platform. The BMS accepted the cell without flagging an incompatible chemistry event, and charge termination triggered correctly at full capacity.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-charge cycle before normal use. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Sudden shutdown at 20–30% on the replacement cell

New Li-ion cells have a steeper voltage cliff than aged cells the fuel gauge IC was originally calibrated against. When the modem or display pulls a current spike, the cell voltage drops sharply — below the BMS cutoff threshold — even though the OS still shows charge remaining. This causes an abrupt shutdown with no warning. Run two full discharge-charge cycles without fast charging. After that, the coulomb counter recalibrates and the reported percentage aligns with the cell's actual voltage curve.

Phone warm near the battery during the first charge after replacement

A new cell starts with higher internal impedance than a conditioned one. The charge IC pushes current into that resistance, and some of it converts to heat — this is normal on cycle one. If the device is noticeably warm but not hot, let it complete the charge uninterrupted. If the chassis becomes uncomfortable to hold, stop the charge and check that the cell is seated flat with no pressure on the contacts. Warmth should drop significantly after the first two full cycles once impedance normalises.