About this replacement
Kyocera DuraTR / E4750 — 3.85V Li-ion Replacement Battery (SCP-71LBPS)
This is a 3.85V, 2700mAh (10.4Wh) Li-ion cell built to fit the Kyocera DuraTR and E4750 smartphones. It matches the OEM footprint at 76.60 × 51.00 × 5.65mm and uses the same SCP-71LBPS / 5AAXBT108GEA part numbers. Drop this in when the original cell no longer holds a usable charge through a standard day.
- DuraTR and E4750 shared platform: Both devices run the same battery bay dimensions, connector pinout, and BMS handshake protocol — the same cell serves both without any modification to the contacts or housing.
- Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the DuraTR platform. The BMS negotiated charge termination correctly, and the coulomb counter registered capacity within expected tolerance of the 2700mAh rating.
- Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge down to automatic shutdown, then charge to 100% uninterrupted. This gives the fuel gauge IC one clean cycle to map its reference curve against the new cell before fast-charge current is applied to an uncalibrated state.
Sudden shutdown at 20–30% on the DuraTR after a cell swap
The DuraTR's fuel gauge IC retains the discharge curve from the old, degraded cell. When the modem fires a high-current burst or the screen peaks in brightness, the new cell's voltage profile doesn't match the stored curve. The phone interprets the voltage reading as critically low and shuts down — even though actual capacity remains. One complete discharge-to-shutdown and full recharge cycle forces the IC to relearn the new cell's voltage-to-capacity relationship and eliminates most premature shutdowns.
USB fast charging not activating on the first cycle after replacement
On the initial charge after a cell swap, the charge IC may default to a low-current trickle mode while it verifies the new cell's internal resistance and BMS response. This is normal behaviour — the phone is not faulted. If fast charging still won't engage after the first full cycle, check that the cable supports the required current rating and that the adapter output matches the phone's charge profile. Fast charging typically resumes normally from the second cycle onward once the BMS has confirmed the new cell is within safe parameters.