Doogee S30 Replacement Battery BAT17S305580 3.8V 5000mAh

Doogee S30 — 3.8V Li-Polymer Replacement Battery (BAT17S305580)

This is a 5000mAh, 3.8V lithium-polymer cell that replaces the original BAT17S305580 battery in the Doogee S30 rugged smartphone. It fits the S30 directly and restores power capacity when the original cell has degraded or failed to hold charge. Capacity is 19Wh as rated.

• S30 platform fit: The S30 uses a fixed battery bay with a specific connector pinout tied to the BAT17S305580 spec. This cell matches that connector, voltage rail, and physical footprint — 79.60 x 56.04 x 6.50mm — so it seats without modification.
• Bench tested on actual hardware: We ran charge and discharge cycles through the S30's charge IC and confirmed the BMS handshake completed correctly. Cell voltage held steady above the protection cutoff under sustained screen and modem load.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one full discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the system applies high-current fast charging to an uncalibrated cell.

Why the S30 reports wrong battery percentage after a cell swap

The S30 uses a fuel gauge IC that tracks charge state against a learned discharge curve from the old cell. When a new cell goes in, that stored curve no longer matches the actual cell chemistry or capacity. The IC keeps estimating from stale data until it relearns. One complete discharge below 5% followed by a full charge to 100% at standard rate forces the IC to recalibrate against the new cell's actual voltage slope.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC still holds the old cell's voltage-to-capacity map and calls a false low-voltage cutoff too early. Under modem or display load, voltage sags briefly — the IC reads that sag as a dead cell and trips the shutdown. The fix is the same recalibration cycle: drain the phone to automatic shutdown, then charge uninterrupted to 100% without interruption. After one full cycle the gauge IC re-anchors its zero point to the new cell's resting voltage of approximately 3.6V at low state-of-charge.