BLU Advance 4.0 Replacement Battery 3.7V 1450mAh C745043160T

BLU Advance 4.0 / A270 — 3.7V Li-ion Replacement Battery (C745043160T)

This is a 3.7V, 1450mAh Li-ion battery for the BLU Advance 4.0 (A270, A270A) smartphone. It replaces part number C745043160T when the original cell degrades or fails to hold a usable charge. Dimensions are 74.26 × 50.05 × 4.00mm — confirm these against your existing battery before installing.

• A270 and A270A compatibility: Both variants share the same battery bay dimensions, connector pinout, and 3.7V nominal voltage rail, so one cell covers the full Advance 4.0 lineup without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Advance 4.0 board. The BMS accepted charge current without tripping, and the protection circuit cut off cleanly at the low-voltage threshold rather than allowing deep discharge.
• Fuel gauge recalibration on first use: Disable fast charging for the first complete discharge-charge cycle after installation. This gives the phone's fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes energy into an uncalibrated cell — preventing erratic percentage readings from the start.

Sudden shutdown at 20–30% on the Advance 4.0 after a cell swap

The Advance 4.0 uses a coulomb-counter-based fuel gauge IC that retains the discharge curve of the old cell in memory. When the replacement cell hits a voltage point the IC associates with a safe operating range, the actual cell voltage under modem or display load can drop below the shutdown threshold faster than the gauge expects. This is a calibration mismatch, not a faulty battery. One full uninterrupted discharge down to auto-shutdown, followed by a full charge, forces the IC to relearn the curve. After one complete cycle, shutdowns at false percentages typically stop.

Phone not powering on after the replacement battery sat in storage

Li-ion cells in storage self-discharge slowly. If the cell drops below approximately 2.5V, the battery's BMS protection circuit locks out to prevent damage, and the phone will show no response — no charging indicator, no boot. Connect the phone to a wall charger rather than a USB port on a PC; wall adapters supply consistent 5V and higher current, which is more likely to trigger the trickle-charge recovery mode the BMS needs to re-initialise. Leave it connected for at least 30 minutes before attempting to power on. If the indicator light appears during that window, the BMS has recovered and normal charging will resume.