User's Manual

9
FUNCTIONAL OVERVIEW
Device power. The PowerMon-5S device is drawing its supply power from the BATT+ / BATT- terminals.
If the device loses power, it will forget the internal clock. The device also monitors the voltage between the
BATT+ and BATT- terminals.
Current shunt. PowerMon-5S contains an integrated 500A / 0.25% precision current shunt. The current
shunt accepts 3/8” ring terminals. Due to the high current potentially passing through the shunt, make sure that
the connections are tight to avoid excessive heating or sparks. Current flowing from BATT+ towards LOAD
(discharging current) will appear in the app as a negative value while current flowing from LOAD towards BATT+
(charging current) will appear as a positive value.
Operation. Once the device receives power it will start advertising its presence to other Bluetooth
devices. Using a phone or tablet running the PowerMon app (found on the App Store / Play Store) the user can
scan for PowerMon devices and connect to one of them at a time (if multiple devices are present). Multiple
PowerMon devices can be distinguished after changing their Bluetooth name using the mobile app. This will be
displayed by the app upon scanning for Bluetooth devices. The factory default name is “PMON-5S”. Once the
mobile app is connected to a power monitor device, the app will display all the measured electrical parameters
in real-time. Tapping on a measurement value for longer than one second will open a menu that allows
operations and configuration specific to that measurement.
Radio performance. The device contains an internal Bluetooth Smart (LE) radio operating in the 2.4GHz
ISM band and an internal antenna. For best performance, the device should be installed in such a way to offer
a path for radio waves to reach it. Metal walls or enclosures can attenuate or completely shield the device. The
mobile device app displays the RSSI value (Received Signal Strength Indication) in real-time.
Power relay control. PowerMon-5S can drive a power relay (either mechanical or solid-state) using the
RELAY terminal. When active (relay turned on), the RELAY terminal is internally connected to ground by the
PowerMon device. The relay should be connected between its power supply (battery positive, typically), and
the RELAY terminal. The low/high voltage disconnect and over-current disconnect functions require the use of
a relay / SSR (Solid State Relay).
Low voltage disconnect. When this mode is enabled, and the battery voltage drops below a specified
value, the device disconnects the load, protecting the battery from over-discharge. In order to disconnect the
load, the voltage has to be below the set threshold for a configurable amount of time. This feature helps in
situations where cranking an engine or a short high current load causes the battery voltage to momentarily
drop. The device will re-engage the power relay a configured amount of time after the condition that caused it
to disconnect is removed.