LN-4C Olympia Viva 1 Replacement Battery 3.7V 1200mAh

Olympia Viva 1 / Viva 2 — 3.7V Li-ion Replacement Battery (LN-4C)

The LN-4C is a 3.7V, 1200mAh Li-ion cell for the Olympia Viva 1 and Viva 2 mobile phones. Both handsets share the same battery bay geometry and connector, so one cell covers both models. Dimensions are 53.00 × 33.90 × 5.70mm — verify against your existing cell before installing.

• Viva 1 and Viva 2 compatibility: Both models run the same 3.7V battery rail with an identical connector and bay footprint. The BMS handshake requirements are the same across both, so one SKU fits either handset without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Viva platform and confirmed the BMS accepted the cell without triggering protection cutoff. Charge acceptance was consistent from the first cycle.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC applies higher current — skipping this step can leave the percentage counter miscalibrated by up to 15%.

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

The Olympia Viva's fuel gauge IC stores a discharge curve from the original cell. A new cell has a different internal resistance profile, so the IC underestimates how fast voltage drops under load from the modem or screen backlight. When actual cell voltage falls below the BMS cutoff threshold — typically around 3.0V per cell — the phone shuts down even though the OS still shows charge remaining. One full discharge-charge cycle at standard rate forces the coulomb counter to relearn the new curve. After that cycle, reported percentage and actual voltage align.

Phone won't power on after the LN-4C sat in storage discharged

Li-ion cells shipped or stored at very low state of charge can fall below 2.5V per cell, which triggers BMS lockout — the protection circuit opens and blocks current flow entirely. Plugging straight into the phone does nothing because the phone's charge IC won't fire until it sees a minimum voltage from the battery. Connect the phone to a wall charger and leave it for 15–20 minutes without pressing any button; most charge ICs apply a low trickle to recover cells from lockout before resuming normal charge. If the phone still shows no response after 30 minutes on the charger, check that cell voltage has recovered to at least 3.0V using a multimeter at the battery terminals.