Orange Sydney Li3708T42P3h553447 Compatible Battery 3.7V 800mAh

Orange Sydney / N295 / Atlanta — 3.7V Li-ion Replacement Battery (Li3708T42P3h553447)

This is a 3.7V, 800mAh Li-ion replacement cell for the Orange Sydney and compatible models including the N295, Atlanta, and F160. It slots into devices where the original cell has degraded and can no longer hold voltage under screen or call load. Capacity is 800mAh (2.96Wh), matching the original specification.

• Sydney, N295, Atlanta, F160 platform fit: These models share the same battery bay dimensions (54.29 × 33.71 × 4.43mm), connector pinout, and BMS handshake protocol — one cell covers the full group without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Sydney platform. The BMS accepted the cell cleanly, charge termination triggered correctly at full voltage, and the protection circuit tripped as expected on simulated over-discharge.
• Fuel gauge recalibration on first install: After fitting this cell, disable fast charging and run one complete discharge-to-charge cycle before normal use. The fuel gauge IC on these devices calibrates its coulomb counter against the cell's discharge curve — skipping this step causes the OS to report inaccurate percentages for the first several cycles.

Sudden shutdown at 20–30% on the Orange Sydney after a cell swap

This is a voltage cliff issue, not a capacity problem. The fuel gauge IC still holds the discharge map from the old, degraded cell, so it underestimates how quickly the new cell's voltage drops under modem or display load. When the actual cell voltage falls below the BMS protection threshold — typically around 3.0V — the device cuts out even though the OS shows charge remaining. One full discharge-recharge cycle forces the coulomb counter to remap against the new cell and eliminates the premature shutdown in most cases.

Device won't power on after sitting in a drawer for months

Li-ion cells self-discharge at roughly 2–3% per month in storage. If the Sydney sat unused long enough, the cell voltage can drop below 2.5V — the threshold where the BMS enters lockout to prevent damage. The phone will show no response to the power button and may not register on the charger at all. Connect it to a wall charger rather than a PC USB port, which limits current; wall charging delivers enough current to pull the cell back above the BMS re-enable threshold, typically around 2.9V, after which normal charging resumes.