Archos 59 Titanium Replacement Battery AC59Ti 3.7V 2400mAh

Archos 59 Titanium — 3.7V Li-ion Replacement Battery (AC59Ti)

This is a 3.7V, 2400mAh Li-ion cell replacing part number AC59Ti in the Archos 59 Titanium and A59 Titanium smartphones. It matches the original voltage and capacity spec exactly. Physical dimensions are 86.95 × 71.05 × 4.30mm — measure your bay before ordering if your unit has been previously repaired.

• 59 Titanium and A59 Titanium fitment: Both model names reference the same hardware platform. The connector pinout, BMS communication protocol, and cell footprint are identical across the 59 Ti lineup, so one cell covers both designations.
• Bench tested on actual hardware: We cycled the cell through charge and discharge under screen-on and modem-active loads. The BMS held cutoff correctly at low voltage and accepted charge current without thermal events through a full cycle.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging and run one complete discharge-to-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated measurement baseline.

Sudden shutdown at 20–30% on the Archos 59 Titanium after a cell swap

This is a voltage cliff issue, not a faulty cell. When the modem transmits or the screen brightness peaks, the new cell draws a short burst of high current. If the fuel gauge IC is still calibrated to the old degraded cell's curve, it reads 25% while the actual cell voltage has already sagged below the shutdown threshold — roughly 3.2V under load. The phone cuts out to protect the hardware, not because the replacement cell is defective. One full discharge-charge cycle at standard current corrects the mismatch between the stored curve and the new cell's actual voltage profile.

Phone won't power on after the replacement cell sat in storage

Li-ion cells self-discharge in storage. If the cell voltage dropped below approximately 2.5V per cell, the BMS enters a lockout state and blocks normal charge current to prevent damage. The phone shows nothing — no charging indicator, no boot. Connect the phone to a wall charger and leave it undisturbed for 20–30 minutes; most BMS controllers accept a trickle current at this voltage and will exit lockout once the cell reaches roughly 3.0V. If the indicator still does not appear after 45 minutes, try a different cable and confirm the charger delivers at least 5V/1A before assuming the cell is at fault.