Orbic R678L5 Replacement Battery BTE-5001 3.85V 4000mAh

Orbic R678L5 / Myra 5G / Magic 5G — 3.85V Li-Polymer Replacement Battery (BTE-5001)

This is a 3.85V, 4000mAh lithium-polymer cell for the Orbic R678L5, R678EL, Myra 5G, and Magic 5G smartphones. It replaces OEM part BTE-5001 and restores power to all core phone functions. Dimensions are 90.50 × 67.50 × 3.90mm — confirm these against your original cell before installing.

• R678L5, R678EL, Myra 5G, Magic 5G compatibility: These four Orbic models share the same battery footprint, connector pinout, and BMS handshake protocol, which is why a single BTE-5001 cell covers all of them.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the R678L5 platform. The BMS accepted the charge profile without fault flags, and voltage held steady under simultaneous screen and modem load.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.

Sudden shutdown at 20–30% on the Orbic R678L5

This is a voltage cliff problem, not a capacity problem. Li-polymer cells have a steep voltage drop near the end of their discharge curve. When the modem fires a transmission burst or the screen peaks in brightness, the cell voltage dips sharply below the BMS cutoff threshold — even though the OS still shows 20–30% remaining. The fuel gauge IC was calibrated to the old cell's curve and misjudges the remaining charge. One full discharge cycle from 100% to auto-shutoff, followed by a full charge to 100%, recalibrates the coulomb counter against the new cell.

Phone won't power on after sitting in storage with a flat battery

If the replacement cell or the original cell discharged below approximately 2.5V during storage, the BMS enters a lockout state to protect the cell from damage. The phone will show no response to the power button and may not display a charging indicator immediately. Connect the phone to a wired charger — not a wireless pad — and leave it for 15–20 minutes before attempting to power on. The charge IC trickle-charges the cell back above the BMS recovery threshold, typically 2.9V, at which point the BMS re-initialises and normal charging resumes.