Archos 50 Replacement Battery AC50PL 3.7V 1800mAh

Archos 50 Series — 3.7V Li-ion Replacement Battery (AC50PL)

This is a 3.7V, 1800mAh Li-ion replacement cell for the Archos 50, 50 Platinum, 50 Helium 4G, and Platinum 50 smartphones. It fits devices using the OEM part number AC50PL. Swap it in when the original cell no longer holds a usable charge across a normal day.

• 50 Series model compatibility: The 50, 50 Platinum, 50 Helium 4G, and Platinum 50 share the same battery bay dimensions, connector pinout, and BMS handshake — all four accept the AC50PL cell without modification.
• Bench tested on actual hardware: We ran the AC50PL through full charge and discharge cycles on the bench. The BMS accepted charge from standard 5V USB, cutoff cleanly at 4.2V, and tripped undervoltage protection at the expected low-cell threshold without false triggers.
• Fuel gauge recalibration on first cycle: After installing this cell, disable fast charging and run one full discharge down to auto-shutdown, then charge uninterrupted to 100%. This gives the fuel gauge IC one clean cycle to map its coulomb counter against the new cell's discharge curve before high-current charging begins.

Sudden shutdown at 20–30% on the Archos 50 after a cell swap

This is a voltage-cliff failure, not a capacity problem. The fuel gauge IC still holds calibration data from the old, degraded cell — so when the new cell's actual terminal voltage drops under modem or screen load, the phone hits real undervoltage before the percentage counter reaches zero. The BMS trips and the device cuts out. One full discharge-to-shutdown followed by an uninterrupted charge to 4.2V resets the coulomb counter to the new cell's curve and eliminates the premature cutoff.

Archos 50 shows incorrect battery percentage after replacement

The fuel gauge IC calibrates itself against a cell's measured discharge curve over time. When you swap in a fresh AC50PL cell, the IC is still running the old degraded cell's curve — so reported percentage drifts away from actual state of charge, often jumping several points at once. This is not a faulty cell. Run two complete discharge-charge cycles without interruption and the IC recalibrates against the new cell. After the second full cycle, percentage reporting stabilises and tracks accurately.