Telstra T930 Replacement Battery 3.7V 900mAh Li-ion

Telstra T930 / Bubble Touch / E810 — 3.7V Li-ion Replacement Battery (Li3710T42P3h483757)

This is a 3.7V Li-ion cell rated at 900mAh (3.33Wh), built to the same form factor as the original battery in the Telstra T930, Bubble Touch, and E810 handsets. All three models share the same battery bay dimensions and connector, so one cell covers the full compatibility range. OEM part number Li3710T42P3h483757 confirms the match.

• T930, Bubble Touch, and E810 compatibility: These three handsets use the same 47.67 × 37.27 × 5.80mm cell with a shared connector pinout and identical voltage rail. The BMS communication protocol is consistent across the range, so no firmware mismatch occurs on swap.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a T930 unit. The BMS accepted the cell without fault flags, and the charge IC reached termination voltage cleanly at 4.2V with no trickle-phase errors logged.
• Fuel gauge recalibration on first use: On first installation, run the phone down to automatic shutdown, then charge to 100% uninterrupted. The T930's fuel gauge IC calibrates its coulomb counter against the new cell's actual discharge curve during this first full cycle — skipping it causes erratic percentage readings for days afterward.

Why the T930 reports wrong battery percentage after a cell swap

The T930 uses a fuel gauge IC that stores a learned discharge curve from the previous cell. When a new cell goes in, the IC is still referencing the old cell's internal resistance and capacity profile. Until it completes a full uninterrupted discharge-to-charge cycle, the percentage display reflects the old curve rather than actual charge state. One complete cycle — flat to full with no interruptions — resets the learned parameters and brings the percentage reading back into accuracy.

Sudden shutdown at 20–30% remaining on the T930

This is a voltage cliff failure, not a capacity issue. Under peak modem or display load, the cell voltage drops sharply below the BMS cutoff threshold — even though the fuel gauge still shows charge remaining. It happens most often on cells that have aged past their cycle rating, or on a replacement cell that has not completed its first full calibration cycle. A fresh cell that has been properly calibrated holds its voltage rail stable under load. After installing this replacement, complete one full discharge cycle and verify stable voltage above 3.6V under active use.