Cameron Nuflo MC-II Plus EXP 3.6V Compatible Battery 14500mAh

Cameron Nuflo MC-II Plus EXP — 3.6V Li-SOCl2 Replacement Battery (9A-100005111)

This is a 3.6V, 14500mAh lithium thionyl chloride cell that replaces the internal backup battery in Cameron Nuflo MC-II Plus EXP, MC-III Plus EXP, MC-II Plus, and MC-III Plus Flow Analyzers. These controllers use the battery to retain SRAM program memory and keep the real-time clock running when mains power is interrupted. Cross-references OEM part numbers 9A-100005111, MV-100005111, and LS33600-CN1.

• MC-II and MC-III Plus platform fitment: Both the standard and EXP variants of these flow analyzers share the same battery bay dimensions, connector, and 3.6V SRAM retention rail — so one cell covers all four listed models without modification.
• Bench tested on actual hardware: We verified open-circuit voltage, confirmed the cell holds above the 3.0V SRAM retention threshold under simulated standby load, and checked that the BMS does not trip during initial float charge draw from the controller.
• Hot-swap protocol for this controller: Always replace this cell with the MC-II or MC-III powered on and in RUN mode. Removing the battery while the controller is off collapses the SRAM supply voltage instantly — all program logic and calibration data is lost and must be reloaded from a programming device.

Why the MC-II Plus EXP loses program memory after a battery swap

The MC-II Plus EXP holds its program, flow calibration tables, and I/O configuration in battery-backed SRAM, not flash. The moment battery voltage drops below approximately 2.8–3.0V — whether from a depleted cell or an interrupted swap — the SRAM loses its charge and all stored data is erased. This is not a firmware fault; it is a physical characteristic of volatile SRAM. Reinstalling a fresh cell after the fact does not recover the lost data — a full program reload from the host laptop or SCADA system is the only path forward.

Battery alarm not clearing on the MC-II Plus after confirmed installation

On Cameron Nuflo flow analyzers, the low-battery alarm flag is written to a status register and does not self-clear when a new cell is installed. The controller checks battery voltage at a timed interval, but the alarm bit persists until it is manually acknowledged through the programming software or front-panel menu. New Li-SOCl2 cells also ship at a storage voltage that can read slightly below 3.6V on first installation — typically 3.5V — and rise to full rated voltage within a few hours on the controller's float supply. If the alarm persists past 24 hours, confirm the cell seating and check the voltage reads above 3.5V before pushing a manual alarm reset in the software.