About this replacement
Archos 45 Neon — 3.8V Li-ion Replacement Battery (AC3000A)
This is a 3.8V, 3100mAh (11.78Wh) Li-ion battery for the Archos 45 Neon smartphone. It replaces OEM part numbers AC3000A and AC3000B. When the original cell loses capacity or fails to hold charge, this cell restores full operation to the handset.
- Archos 45 Neon fit: The 45 Neon uses a specific connector pinout and BMS handshake tied to the AC3000A/AC3000B cell spec. This replacement matches that voltage rail and physical footprint — 74.92 × 55.43 × 5.80mm — so it seats correctly without modifying the battery bay.
- Bench tested on actual hardware: We cycled this cell through charge and load on the 45 Neon platform. The BMS accepted the cell without triggering a fault state, and the charge IC completed a full CC/CV cycle to 3.8V nominal as expected.
- First-cycle calibration tip: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map its coulomb counter against the new cell's discharge curve before high-current charging begins on an uncalibrated cell.
Why the Archos 45 Neon reports wrong battery percentage after a cell swap
The 45 Neon uses a fuel gauge IC that tracks charge state using a coulomb counter calibrated to the original cell's discharge curve. When a new cell goes in, that curve no longer matches. The IC reports percentage against stale reference data, so the number on screen drifts from the actual state of charge. One full discharge down to automatic cutoff, followed by a complete charge to 100%, forces the IC to re-anchor its reference points to the new cell.
Sudden shutdown at 20–30% on the replacement cell
This happens when the modem or display fires a high-current draw and the cell voltage drops below the BMS cutoff threshold faster than the fuel gauge tracks it. The phone shuts off even though the percentage counter still reads 20–30%. The root cause is the fuel gauge IC running an uncalibrated curve — it has not yet learned where the new cell's voltage cliff sits under load. Run two full discharge-charge cycles, and the IC recalibrates; shutdown should shift back to below 5% reported charge.