Telefunken Selfie TS1 Compatible Battery LP435255A 3.7V 1500mAh

Telefunken Selfie TS1 — 3.7V Li-ion Replacement Battery (LP435255A)

This is a 3.7V, 1500mAh Li-ion cell built to the LP435255A spec for the Telefunken Selfie TS1 smartphone. It replaces the original battery when the phone no longer holds a usable charge, shuts down unexpectedly, or fails to power on. Voltage and capacity match the stock specification — 3.7V nominal, 5.55Wh total energy.

• Selfie TS1 fitment: The LP435255A cell dimensions — 58.50 × 51.95 × 4.30mm — match the battery bay on the Selfie TS1. The connector orientation and BMS pinout align with the charge IC on the TS1 mainboard, so the phone reads cell state correctly after installation.
• Bench tested on actual hardware: We cycled this cell through charge and discharge under modem and screen load conditions. The BMS held the cutoff voltage correctly and reported state of charge without erratic jumps after one full calibration cycle.
• First-cycle fuel gauge recalibration: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the Selfie TS1 after a cell swap

A fresh Li-ion cell has a slightly different discharge curve than the aged cell the fuel gauge IC was calibrated to. When the phone predicts 25% remaining but the cell voltage is already dropping sharply under modem or screen load, the protection circuit cuts power before the OS can save state. This is a calibration gap, not a faulty cell. One full discharge to automatic shutdown followed by an uninterrupted charge to 100% resets the coulomb counter against the new curve. After that cycle, the percentage readings stabilise and early shutdowns stop.

Phone warm near the battery during the first few charges after replacement

A new cell starts with higher internal impedance than a cell that has been cycled. The charge IC on the Selfie TS1 pushes the same current it used with the broken-in original cell, so more energy converts to heat in the first few sessions. This is normal and fades after three to five charge cycles as the cell's impedance drops. If warmth persists beyond five cycles or the phone feels hot rather than warm, check that the replacement connector is fully seated — a partial connection raises contact resistance and amplifies heating at the joint.