Olympia Vox Color Replacement Battery 3.7V 550mAh

Olympia Vox Color / Vox Color 2159 — 3.7V Li-ion Replacement Battery

This 3.7V, 550mAh Li-ion cell replaces the original battery in the Olympia Vox Color and Vox Color 2159 mobile phones. These compact early-2000s handsets used a slim 53 x 34 x 4.80mm cell format that is no longer widely stocked. This listing covers both model variants — same cell, same connector, same fit.

• Vox Color and Vox Color 2159 compatibility: Both handsets share the same battery bay dimensions and voltage rail. The connector orientation and cell thickness are identical across the two variants, so one SKU covers both without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Vox Color platform and confirmed the BMS accepted the new cell without triggering a protection cutoff. Charge current stabilised correctly at the termination threshold.
• Fuel gauge recalibration on first cycle: On first use after fitting, run the phone down to automatic shutdown, then charge uninterrupted to 100% before using it again. The fuel gauge IC in the Vox Color was calibrated to the original cell's discharge curve — one full cycle resets that reference point to the new cell.

Sudden shutdown at 20–30% on the Vox Color after a cell swap

The Vox Color's fuel gauge IC tracks charge state against a stored discharge curve from the factory cell. A new cell has a slightly different voltage-versus-capacity curve, so the IC can misread remaining charge. When the phone's processor and RF transmitter draw current simultaneously — during a call, for example — the cell voltage dips below the BMS trip threshold before the gauge reaches zero. The phone cuts out even though the display shows charge remaining. One complete discharge-charge cycle corrects the stored curve and eliminates the false cutoff.

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

Li-ion cells shipped or stored for extended periods can drop below 2.5V per cell. At that level, the BMS enters lockout mode and blocks current flow to protect the cell from damage. The Vox Color may show no sign of life — no boot screen, no charging indicator. Connect the phone to a charger and leave it for 15–20 minutes without pressing the power button. Most BMS circuits on cells at this voltage level will accept a trickle pre-charge that brings the cell back above the lockout threshold, after which normal charging resumes and the phone will power on.