Brondi S602 Smartphone Replacement Battery 3.8V 2600mAh

Brondi Amico Smartphone XL — 3.8V Li-ion Replacement Battery (S602)

This 3.8V, 2600mAh Li-ion cell replaces the original S602 battery in the Brondi Amico Smartphone XL. It fits the physical bay and connector of the Amico Smartphone XL directly. Capacity comes from product data at 9.88Wh — no third-party estimates used here.

• Amico Smartphone XL fit: The S602 part number covers the Amico Smartphone XL specifically. The cell dimensions — 94.15 × 64.25 × 4.80mm — match the original bay. The connector pinout carries the same thermistor line the phone's charge IC expects, so the board accepts the cell without flagging an incompatible pack.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on a Brondi Amico Smartphone XL. The BMS reported no fault codes. The charge IC accepted the cell on the first connection and held a steady taper current through to termination.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-charge cycle at standard rate. The fuel gauge IC in the Amico Smartphone XL calibrates its coulomb counter against the discharge curve of whichever cell it sees first. Skipping this step causes the OS to report inaccurate percentages until the counter resets itself — which can take several uncontrolled cycles.

Sudden shutdown at 20–30% on the Amico Smartphone XL after a cell swap

A new cell has a slightly different voltage-to-capacity curve than the worn cell the fuel gauge IC was trained on. When the Amico Smartphone XL's modem fires a high-current burst — during a call or mobile data handoff — the cell voltage momentarily drops. If the fuel gauge still thinks 25% charge equals a safe voltage, but the actual cell hits the 3.0V cutoff under that load, the BMS trips and the phone shuts off. One full slow-rate discharge cycle lets the coulomb counter map the real curve of the new cell. After that cycle, the shutdown threshold and the displayed percentage align correctly.

Phone feels warm near the battery during the first charge after replacement

A factory-fresh cell has higher internal impedance than a cell that has been through several charge cycles. The Amico Smartphone XL's charge IC pushes current into the new cell at the same rate it used with the broken-in original. Higher impedance means more energy converts to heat at the cell surface during that first charge. This is normal and typically fades after two to three cycles as impedance drops. If the phone remains noticeably warm past the third charge, check that the back cover is seated fully — any gap reduces heat dissipation from the cell to ambient air.