Archos 45 Helium 4G Compatible Battery 3.7V 1550mAh TBW5986

Archos 45 Helium 4G — 3.7V Li-ion Replacement Battery (TBW5986)

This is a 3.7V, 1550mAh Li-ion cell that replaces the original battery in the Archos 45 Helium 4G, 45b Helium 4G, and 50c Neon smartphones. It matches OEM part numbers TBW5986 and AC300CA. Voltage, dimensions (64.53 × 49.75 × 4.56mm), and connector orientation match the original cell.

• 45 Helium 4G, 45b Helium 4G, and 50c Neon compatibility: All three models share the same battery bay dimensions, 3.7V supply rail, and connector pinout. The BMS handshake on each uses the same two-wire communication line, so one cell works across all three without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the 45 Helium 4G platform. The BMS accepted the cell without fault codes, held stable voltage under simultaneous LTE and display load, and cut off cleanly at the low-voltage threshold.
• First-cycle fuel gauge reset: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the charge controller applies high-current input to an uncalibrated cell.

Sudden shutdown at 20–30% on the Archos 45 Helium 4G

This is a voltage cliff failure. Under combined LTE modem and screen load, internal cell resistance causes voltage to drop sharply — even when the fuel gauge still reads 20–30%. The phone's low-voltage protection trips before the gauge catches up. It happens most often on aged cells where impedance has climbed. A new cell with lower internal resistance sustains voltage under that same load, so the cliff disappears.

Phone reports wrong battery percentage after cell swap

The fuel gauge IC on these Archos devices uses a coulomb counter calibrated to the discharge curve of the original cell. Swap in a new cell and the counter is working off the wrong reference — reported percentage drifts or jumps. One full discharge cycle from 100% down to the automatic cutoff, then a full charge to 100%, forces the IC to rebuild its curve against the new cell. After that cycle, percentage reporting stabilises.