Archos 50c Neon Replacement Battery 3.7V 1400mAh AC1850A

Archos 50c Neon / 45B Helium — 3.7V Li-ion Replacement Battery (AC1850A)

This is a 3.7V 1400mAh Li-ion cell rated at 5.18Wh, replacing part number AC1850A. It fits the Archos 50c Neon and Archos 45B Helium Android smartphones. Install it when the original cell no longer holds a usable charge or fails to power the device.

• 50c Neon and 45B Helium compatibility: Both models share the same battery bay dimensions, connector pinout, and BMS communication protocol — the AC1850A part number covers both. No adapter or modification is needed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on both device models and confirmed the BMS handshake completes without fault codes. The protection circuit tripped correctly at the low-voltage cutoff threshold during deep-discharge testing.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one full discharge-to-charge cycle before normal use. The fuel gauge IC on these Archos devices calibrates against the cell's discharge curve — skipping this step causes the percentage readout to drift against the new cell's actual capacity.

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

This is a voltage cliff issue, not a capacity defect. The fuel gauge IC still holds the discharge curve from the old degraded cell and predicts remaining charge incorrectly. When the modem or display draws a burst of current, the new cell's voltage drops below the cutoff threshold before the gauge reaches 0%. One complete discharge-to-charge cycle lets the coulomb counter relearn the new cell's actual voltage-versus-capacity curve and eliminates premature shutdowns.

Device not powering on after the replacement battery sat in storage

Li-ion cells self-discharge during storage. If the cell voltage drops below approximately 2.5V, the BMS enters lockout mode and blocks charge current to prevent thermal runaway on a deeply discharged cell. The phone will show no response when connected to a charger. Connect the device to a wall charger — not a USB port — and leave it undisturbed for 20–30 minutes. Most BMS circuits on these Archos models will accept a trickle recovery current and release lockout once the cell climbs back above 3.0V.