BLU Tank 2.4 Torch Replacement Battery 3.8V 2800mAh

BLU Tank 2.4 Torch / T550 — 3.8V Li-ion Replacement Battery (C814670300L)

This is a 3.8V, 2800mAh Li-ion replacement battery for the BLU Tank 2.4 Torch and T550. It fits the original battery bay using the same connector and cell dimensions as the factory unit. Swap it in when the original cell no longer holds a charge or the phone shuts down unexpectedly under load.

• Tank 2.4 Torch and T550 fitment: Both models share the same battery bay geometry, connector pinout, and BMS handshake protocol, so one cell covers the full Tank 2.4 Torch line. The 80.50 × 46.04 × 7.00mm form factor seats flush without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Tank 2.4 Torch platform. The BMS accepted the charge handshake on the first cycle, and the protection circuit tripped correctly at the low-voltage cutoff threshold without nuisance shutdowns.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge down to automatic shutoff before charging back to 100%. This gives the fuel gauge IC a complete reference curve against the new cell before high-current charging begins. Skipping this step is the main cause of erratic percentage readings in the first week.

Sudden shutdown at 20–30% on the Tank 2.4 Torch after a cell swap

The Tank 2.4 Torch runs an active modem and a bright torch LED simultaneously, both of which spike current draw hard and fast. If the fuel gauge IC is still calibrated to the old cell's discharge curve, it reads the state of charge too optimistically. When the new cell hits its actual voltage floor under that combined load, the BMS cuts power before the OS has a chance to initiate a graceful shutdown. One full slow-charge cycle resets the coulomb counter and maps the new cell's real discharge profile. After that cycle, shutdowns at 20–30% typically stop.

Phone not powering on after the replacement battery sat in storage

Li-ion cells self-discharge in storage, and if this battery dropped below approximately 2.5V per cell before installation, the BMS will have locked out to prevent damage. The phone will show no response — no charging animation, no boot attempt. Connect to a wall adapter rated at 5V and leave it for 20–30 minutes without pressing anything. The charge IC will trickle current into the cell until the BMS re-initialises and releases the lockout. Once the charging animation appears, proceed with a normal full charge before powering on.