About this replacement
Kyocera SE47 / SE44 / V5 Slider — 3.7V Li-ion Replacement Battery (TXBAT10020)
This is a 3.7V, 950mAh Li-ion replacement battery for the Kyocera SE47, SE44, and V5 Slider smartphones. It replaces OEM part numbers TXBAT10020 and TXBAT10035. Fits the original battery bay without modification.
- SE47, SE44, and V5 Slider compatibility: These three models share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers all three. The 3.7V nominal voltage rail matches what each device's charge IC expects.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the SE47 platform and confirmed the BMS communicated cleanly with the device charge IC, with no false low-battery shutdowns during the test sequence.
- Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before fast charge pushes higher current into an uncalibrated cell.
Sudden shutdown at 20–30% on a freshly installed cell
The Kyocera SE47 uses a fuel gauge IC that was calibrated to the discharge curve of the original aged cell. A new cell holds voltage higher for longer, then drops off at a steeper cliff under modem or screen load. The gauge misreads that cliff as 20–30% remaining and the phone shuts off before the percentage hits zero. One full discharge-charge cycle at standard rate resets the coulomb counter and resolves this within two to three cycles. After recalibration, the percentage readout tracks the actual cell state correctly down to the low-voltage cutoff near 3.0V.
Phone stays on the Kyocera boot screen and will not reach the home screen after battery swap
If the replacement cell shipped or sat in storage below 2.5V per cell, the BMS enters lockout mode and cannot supply enough current to complete the boot sequence. The phone draws a surge during modem initialisation that the locked BMS cannot deliver. Connect the phone to a wall charger — not a PC port — and leave it for 20 minutes before attempting to power on. A wall adapter delivers enough trickle current to bring the cell above the BMS recovery threshold of approximately 2.7V, at which point the protection circuit re-engages and the phone will boot normally.