Airmax Power Usage
Topics Included
1. Safety Information
2. Device Impact on Vehicle Battery
3. Airmax Device Power Modes
1. Safety Information
Please adhere to the following safety and installation information at all times.
RTU Supply Voltage +6V to +16V Maximum neg ground.
(Overvoltage and transient protection.)
+6V to +16V Maximum neg ground.
RTU Power Consumption
Operating current <100mA (2.0 Amp peak) Sleep current < 5mA, “Sleep” < 5mA
Note:
- The Airmax RTU is internally fused
- The currents indicated above are worst case scenario when the device is transmitting at peak power (2.0 Amp peak) and typically a lot lower than illustrated
Important – the device’s power supply for the vehicle installation MUST utilise a permanent power feed provided by the vehicle OBD connector, that is NOT subject to a battery isolation ‘kill switch’ technology. If the vehicle is fitted with a battery isolation ‘kill switch’ then the permanent power feed must be taken directly from the vehicle battery terminals whereby you may wish to use additional fuses.
2. Device Impact on Vehicle Battery
Under normal conditions, the Airmax device does not impact the vehicle’s battery life.
Subject to the vehicle, the Airmax device uses either motion, ignition, crank detection, or battery voltage to wake up and switch to full-power mode. After each trip, the Airmax device remains in full-power mode for up to 10 minutes before shifting to low-power mode. If all data is transmitted when the key is turned off, the device enters sleep mode within 30 seconds. Otherwise, it stays active for up to 10 minutes to transmit any pending data before entering low-power mode.
The device is configured to wake up periodically during extended vehicle parking or underutilisation periods (known as a ‘Heartbeat’). The purpose is to report on device health and the latest location position. This is subject to GSM signal coverage, which could be impacted by the parking location.
These intervals are dynamic and will back off from 6 to 48 hours over a 5-day period.
During this period, the device will be in low-power mode (“sleep”). During the Heartbeat state, the device does not communicate over CAN and draws minimal power for 30 seconds.
3. Airmax Device Power Modes
When the vehicle is powered on and in operation, the device functions with all features fully enabled. However, after the engine is turned off, the Airmax device shuts down to conserve energy and reduce power consumption. This limited operation helps preserve battery capacity, especially for smaller batteries, and extends the battery life for vehicles that remain idle for long periods.
If the Airmax device detects the vehicle battery voltage dropping below 10.8V while the vehicle is stationary, it will automatically suspend Heartbeats until the battery voltage increases. During a period where Heartbeats are suspended, the Portal will display ‘No Comms’ and its last reported values and location. The device will only return to full-power mode as soon as it detects movement, engine cranking, ignition and battery voltage improves.
The table below outlines the active features for each phase of the battery power cycle:
The device reports battery voltage and sends alerts when thresholds are exceeded. The default configuration reports the resting battery level as outlined in the table below.
