FS3 Factstar:

Float Current Monitor

The FS3 Factstar is a cost effective battery monitor. The device uses Polytronics revolutionary float current monitoring technique along with battery segment measurements to determine battery status. Factstar records discharge/charge frequency and duration, and will alarm the user of open or shorted strings, high float current, and pending thermal runaway conditions.

The FS3 uses float current measurements in conjunction with measurements of battery segment voltages to provide a clear indication of battery health and alert personnel of impending battery problems well in advance of failure.

The high sampling speed and low cost of the system make it ideally suited for monitoring batteries used in Telco and Diesel Generator applications.

The FS3 is designed with simplicity in mind. The system can be installed in minutes. Simple alarms indicate whether the battery is good, bad, or in need of service while the system collects and stores battery data that can be analyzed using the BTM Global or imported directly into a spreadsheet or database application.

Battery Segment Voltages

Battery segment voltages provide additional information on the battery health and age. The system can be used as a standalone device or integrated into an existing facility management system or UPS. is is compatible with our BTM Global, which allows the monitoring of thousands of distinct sides from a centralized location.

Float Current

Float current is the current present when the battery is in a floating condition. Float current will commonly change in a very predictable nature, thus leading to the FS3 easily discovering possible battery failure.

Impending Thermal Runaway Detection

By monitoring battery floating current and temperature, our patented Float Current Monitor (FactStar) is capable to detect impending thermal runaway conditions well before they become dangerous. FactStar can be configured to generate an alarm that provides advanced warning of approaching thermal runaway.

Using the available Ethernet option, the FS3 is capable of acting as a standalone web server on a network, thus making it viewable from any browser

Detection and Measurement of:

  • Impending Thermal Runaway
  • Common Charger Malfunctions
  • Aging Battery Conditions
  • Shorted Battery Cells
  • Open Battery String
  • High Temperature
  • Insufficient Cooling
  • High AC Ripple
  • Battery Segment Voltages
  • Discharge/Charge Profiles


Technical Specifications
Supply 12 - 60 V DC
Power Source AC Adapter or directly from battery
Analog Output 0 - 3 V (optional)
Digital Output RS232 / RS485 / Fiber Optic Mode / Ethernet (determined at time of purchase)
Operational Range Max. Current: 600A
Max. Voltage: 750 VDC
Alarm Conditions
  • High Float Current
  • Thermal Runaway
  • Ground Fault
  • Temp. out of limits
  • Open String
  • High AC Ripple
  • String Exhausted and segment V abnormalities
Sampling Speed 200 milliseconds
Averaging Configurable
Size 5.625" x 3.5" x 1.25"
Resolution 1mA and 0.3V
Records and store AH, Float, Charge, Discharge and Ripple Current (rms and peak), segment voltages can withstand thousands of amperes of current

Sample Configuration

Facstar Diagram