Manta TEL2405 Replacement Battery 3.7V 900mAh

Manta TEL2405 / TEL2408 — 3.7V Li-ion Replacement Battery

This 3.7V, 900mAh Li-ion cell replaces the original battery in the Manta TEL2405 and TEL2408 smartphones. It physically measures 53.00 × 34.00 × 4.30mm and slots into the same bay as the factory cell. If your phone is shutting down unexpectedly or no longer holding a charge, this is the direct swap.

• TEL2405 and TEL2408 compatibility: Both models run the same 3.7V single-cell architecture with an identical battery bay footprint. The connector pinout and BMS communication protocol are shared across the pair, so one cell covers both handsets without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a controlled rig. The BMS accepted charge input without error, held voltage within tolerance across the full discharge curve, and triggered protection cutoff cleanly at the low-voltage threshold.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.

Why the TEL2405 reports wrong battery percentage after a cell swap

The fuel gauge IC on these Manta handsets stores a learned discharge curve from the original cell. When a new cell goes in, the IC still references the old curve, so reported percentage drifts from actual state of charge. This shows up most often as the phone reading 40% and then jumping to 15% under modem load. One full uninterrupted discharge-to-shutdown followed by a full charge lets the coulomb counter reset and map the new cell accurately.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff issue, not a capacity fault. When the modem transmits or the screen peaks brightness, current draw spikes and a partially aged — or freshly installed uncalibrated — cell drops below the BMS cutoff voltage for a split second, triggering shutdown. The phone shows 25% because the fuel gauge IC hasn't mapped where voltage actually collapses under load on the new cell. Run one full discharge cycle without interruption, then charge to 100% — the IC recalibrates the cutoff threshold against real load data and the shutdowns stop.