Orange Rio Replacement Battery 3.7V 800mAh Li3709T42P3h504047

Orange Rio / GX991 / X990 / X998 Series — 3.7V Li-ion Replacement Battery (Li3709T42P3h504047)

This is a 3.7V, 800mAh Li-ion cell for the Orange Rio, GX991, X990, and X998 smartphones. It replaces the OEM cell when the original has degraded past normal use. Fits the physical bay and connector used across this device family.

• Rio / GX991 / X990 / X998 platform fit: These four models share the same battery bay dimensions (50 × 39 × 5mm), connector pinout, and BMS handshake protocol — a single cell covers all of them without modification.
• Bench tested on actual hardware: We cycled the cell through charge and discharge on the Rio platform. The BMS accepted the cell without triggering protection cutoff, and charge termination fired correctly at 4.2V.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's actual discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the replacement cell

The Rio's fuel gauge IC stores a learned discharge curve from the old cell. When a new cell goes in, that curve no longer matches the actual voltage-to-capacity relationship. The phone sees a voltage cliff — the cell voltage drops below the SoC threshold under modem or screen load — and trips a protective shutdown before the displayed percentage reaches zero. Running one full discharge cycle from 100% to auto-off, then charging uninterrupted to 100%, resets the coulomb counter. After that cycle, reported percentage tracks actual capacity correctly.

Phone stays on the Orange logo after fitting the replacement cell

If the original battery sat discharged for an extended period, the BMS on the replacement cell may have also dropped below its lockout threshold during storage — typically below 2.5V per cell. The phone cannot boot from a cell in BMS lockout because the protection circuit blocks output. Connect the phone to a wall charger and leave it for 15–20 minutes without pressing the power button; the charger feeds a trickle current that brings the cell above the lockout floor. Once the cell clears approximately 3.0V, the BMS re-enables output and the phone will boot normally.