Merlin Power Systems
version: 2.0.2
SmartGauge Installation and User Guide
Page 3
Monitoring and Display of Auxiliary Battery Voltage
Monitoring and Display of Auxiliary Battery State of Charge (SoC)
Monitoring and Display of Secondary Battery Voltage
User Defined High/Low Battery Voltage Alarms for Each Battery
User Defined High/Low SoC Alarm for Auxiliary Battery
Bright LED Daylight Display Screen
Volt Free Alarm Contact for Firing External Alarms, Relays etc
Conventional battery monitor systems count amp hours in/out of the batter to determine SoC. This
method is inherently inaccurate due to the SoC of the battery not necessarily being linked to the
amount of energy a battery can deliver. Factors such as temperature, battery charge/discharge rate,
incorrectly installed shunts and battery age all contribute to this inaccuracy. Unless the conventional
battery monitor is regularly reset (either automatically by fully charging the battery or manually), the
reading error will compound (known as synchronisation error).
For batteries being used in standby (nominal zero current) applications, Amp Hour counters will run
out of synchronisation as there are very low or no amps flowing through the shunt. Self discharge of
the batteries cannot be accounted for so, simply by just not using your electrical system, an amp
hour counter will display incorrect State of Charge Values.
SmartGauge uses just two wires to monitor the battery. Proprietary test methods are employed by
the SmartGauge to generate data. This data is then compared to detailed computerised battery
models. SmartGauge compares real world data with those models to generate SoC information. In
independent testing SmartGauge was found to be within 5% accuracy at all times.
Highly accurate SoC information not only allows you to confidently make decisions about how you
use your electrical system, it also allows you to automate certain functions like load shedding or
generator start/stop.
SmartGauge uses a self-correcting algorithm to determine battery SoC – over time it becomes more
and more accurate. This self-correction also means that SmartGauge automatically adjusts for
battery degradation over time. SmartGauge only needs 2-3 charge/discharge cycles to synchronize
with the batteries.
SmartGauge also interfaces with the Merlin SmartBank for highly advanced split charging – see
SmartBank manual for details.
1.1 Main SmartGauge Features
1.2 Why SmartGauge?
