ViewSonic CR2032CL-58 NetTop VOT133 Replacement Battery 3V

ViewSonic NetTop VOT133 — 3V Lithium Replacement Battery (CR2032CL-58)

This 3V, 220mAh lithium coin cell replaces the CR2032CL-58 in the ViewSonic NetTop VOT133 and VS14165. It powers the real-time clock and CMOS memory, keeping system time and BIOS settings intact when mains power is removed. When the original cell depletes, the system loses its clock and may reset BIOS configuration on every cold boot.

• VOT133 and VS14165 fit: Both models use the same RTC circuit and CR2032CL-58 footprint. The cell sits on the same motherboard socket with identical polarity orientation and no BMS handshake — a direct socket swap covers both units.
• Bench tested on actual hardware: We measured open-circuit voltage at 3.00–3.05V before installation. On the VOT133 board, the RTC held time correctly across repeated power-off cycles and the CMOS checksum passed POST without error.
• RTC swap procedure for the VOT133: This is a desktop CMOS cell, not a hot-swap unit. Shut the system down fully and unplug the AC cable before opening the chassis. After fitting the new cell, re-enter BIOS on first boot to reset the system date and time — the RTC does not retain values from the dead cell.

Why the VOT133 shows the wrong date and time after a cold boot

The CR2032CL-58 is the sole power source for the RTC when AC power is absent. Once cell voltage drops below roughly 2.5V, the RTC circuit loses its reference and the clock resets to a default date — typically January 1, 2000 or the BIOS compile date. The system may also flag a CMOS checksum error at POST because stored settings are no longer validated against a live cell. Replacing the cell and manually resetting the clock in BIOS resolves both symptoms immediately.

BIOS settings reverting to defaults after every shutdown

If boot order, onboard device settings, or custom BIOS values reset every time the VOT133 is unplugged, the CMOS cell is no longer holding charge between sessions. A depleted cell reads below 2.0V under the light load of the RTC circuit — enough for POST to pass once but not enough to retain NVRAM writes. Fit the new CR2032CL-58, power the system on, re-enter BIOS, save all settings with F10, then confirm they persist across a full shutdown and cold boot. If settings still revert, check the cell socket for corrosion or a bent retaining clip preventing firm contact.