Archos AC35BTI 35b Titanium Compatible Battery 3.7V 1600mAh

Archos 35b Titanium — 3.7V Li-ion Replacement Battery (AC35BTI)

This is a 3.7V, 1600mAh Li-ion replacement battery for the Archos 35b Titanium and 35b Titanium Dual SIM smartphones. It replaces OEM part AC35BTI and fits the original battery bay without modification. Capacity is 5.92Wh — matching the factory specification in the product data.

• 35b Titanium and Dual SIM compatibility: Both variants share the same battery bay dimensions (64.60 x 44.00 x 5.10 mm), the same 3.7V nominal voltage rail, and the same connector pinout. One cell fits both models without adapter or wiring change.
• Bench tested on actual hardware: We cycled this cell through a full charge and discharge on the 35b Titanium platform. The BMS accepted the charge current without interruption and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first cycle: After fitting this replacement, run one complete discharge to automatic shutdown, then charge uninterrupted to 100% before normal use. The Archos fuel gauge IC calibrates its coulomb counter against the new cell's discharge curve during that first full cycle — skipping it causes percentage drift from the first day.

Sudden shutdown at 20–30% on the 35b Titanium after a cell swap

The Archos 35b Titanium fuel gauge IC was calibrated to the original cell's internal resistance curve. A new cell has a different voltage-under-load profile, so the gauge misjudges remaining capacity. When the modem fires up for a call or the screen hits full brightness, current draw spikes and the cell voltage drops below the BMS cutoff threshold — even though the reported percentage still shows 20–30%. The fix is one full uninterrupted discharge-charge cycle, which forces the coulomb counter to remap against the new cell.

Device not powering on after the replacement cell sat in storage

Li-ion cells that have discharged below approximately 2.5V in storage trigger a BMS lockout to prevent damage during charge recovery. The 35b Titanium may show no response at all — no boot, no charging indicator — when this lockout is active. Connect the phone to a wall charger and leave it for 15–30 minutes without pressing the power button. The charge IC trickle-charges the cell back above the BMS re-enable threshold, typically around 2.9V, at which point the phone will show a charging screen and boot normally.