Olympia Viva 1 LN-4C Replacement Battery 3.7V 750mAh

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

This is a 3.7V, 750mAh Li-ion cell that replaces the OEM LN-4C battery in the Olympia Viva 1 and Viva 2 smartphones. It fits the compact battery bay on both handsets and restores normal device operation when the original cell has degraded. Capacity figure is 750mAh (2.78Wh) as specified in the product data.

• Viva 1 and Viva 2 compatibility: Both models use the same LN-4C cell format — identical footprint at 53.00 × 33.90 × 5.70mm, same 3.7V nominal rail, and the same three-pad connector. One replacement cell covers either handset.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the Viva platform. The BMS accepted the cell without fault flags, and the charge IC cycled correctly through CC/CV phases to termination.
• Fuel gauge recalibration on first install: On first use after fitting this cell, disable fast charging and complete one full discharge-to-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging is applied to an uncalibrated cell.

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

A fresh Li-ion cell has a steeper voltage cliff than an aged one. When the Viva's modem fires a high-current burst — during a call or data sync — the new cell's terminal voltage dips sharply. If the fuel gauge IC still holds calibration data from the old degraded cell, it misreads remaining capacity and the phone shuts down before the percentage reaches zero. One full discharge cycle from 100% to automatic cutoff, followed by a full charge without interruption, resets the coulomb counter and eliminates the premature shutdown.

Phone won't power on after sitting in a drawer for months

Li-ion cells self-discharge in storage. If the Viva sat unused long enough, the cell voltage dropped below 2.5V and the BMS entered a protective lockout state to prevent cell damage. The phone will show nothing when you press the power button — no logo, no charge animation. Connect it to a wall adapter rated at 5V/1A and leave it for 20–30 minutes; the charge IC trickle-charges the cell back above the BMS re-enable threshold, typically around 2.9V, after which normal charging resumes.