Honeywell 51199942-300 | 3.6V Controller Battery

Product Overview

This controller battery preserves system memory and maintains real-time clock accuracy during power loss events. Manufacturing plants cannot afford to lose configuration data after unexpected shutdowns. The 51199942-300 connects directly to Honeywell controller boards via a standard 2-pin connector. Its high-grade lithium chemistry ensures stable voltage delivery over many years. Control engineers can perform hot-swap replacements without cycling main system power. The battery’s robust construction withstands harsh industrial temperature extremes.

Technical Specifications

Parameter	Specification
Battery Chemistry	Lithium thionyl chloride (Li-SOCl₂)
Nominal Voltage	3.6 VDC
Rated Capacity	2700 mAh
Continuous Discharge Current	150 mA maximum
Pulse Discharge Current	500 mA (for 1 second)
Operating Temperature	–55°C to +85°C
Storage Life	10+ years (at 25°C)
Expected Service Life	6–8 years in typical applications
Recommended Replacement Cycle	Every 5 years
Connector Type	2-pin Molex-style with friction lock
Lead Wire Length	200 mm ±15 mm
Cell Dimensions	33.5 mm diameter x 64.5 mm height
Total Assembly Weight	0.14 kg
Safety Approvals	UL recognized, IEC 60086-4 compliant

Energy Storage and Discharge Profile

The 51199942-300 stores 9.72 watt-hours of energy at its nominal 3.6-volt rating. Its exceptionally low self-discharge rate retains 85% of capacity after ten years of storage. The battery sustains a flat discharge curve, which ensures consistent processor operation. Internal impedance measures below 3 ohms to support high peak current demands. This assembly tolerates extreme cold down to –55°C without performance degradation.

Physical Construction and Wiring

A rugged shrink-wrap sleeve protects the cell from moisture and physical damage. Stranded copper leads with tin-plated terminals provide reliable electrical connectivity. The friction-lock connector prevents accidental dislodging in high-vibration environments. Weighing just 140 grams, this assembly poses minimal strain on board-mounted headers. Its 200-millimeter lead length allows flexible placement away from heat-generating components.

Safety Engineering and Protection

A built-in venting mechanism releases internal pressure safely under fault conditions. The cell design incorporates non-flammable electrolyte to minimize fire risks. Series blocking diodes in the controller prevent any charging current from reaching the battery. Insulated leads feature dual-wall thickness for abrasion resistance. The battery meets all UN 38.3 transport safety requirements for hazardous materials.

Monitoring and End-of-Life Indication

The host controller continuously samples battery voltage through an on-board analog channel. A user-adjustable alarm threshold warns maintenance teams of impending depletion. The controller logs power-fail events and battery age in its diagnostic memory. Visual status LEDs display battery health as green, yellow, or red states.