• 5
EN
FUNCTIONS
• General
SMARTPASS 120T is a Power Management Solution which distributes, controls and maximizes
available energy from the vehicle alternator to service batteries and other consumers.
SMARTPASS 120T connects the service battery to the alternator/starter battery in order to split
charge and deliver up to 120A continuously to the service battery and parallel consumers.
• Split charging
SMARTPASS 120T connects the service battery to the starter battery when the alternator is
running, or when the starter battery voltage is kept above a set threshold by another power
source, for example an external battery charger.
• Battery separation
SMARTPASS 120T separates the starter battery from the service battery when the engine is not
running. The battery separation protects the starter battery from being discharged, this eliminates
the needs for diodes and VSR relays
• Service Battery guard (Deep discharge protection)
Turns off all the equipment connected to the SMARTPASS 120T consumer output when service
battery voltage is low, this protects the service battery from deep discharge and will extend
battery life. The consumer output will reconnect when service battery voltage has increased back
to a level within specified operating range.
• Critical consumers
If there are some consumers with low power consumption that must be prioritized (critical
consumers), they can be connected directly to battery. This will ensure they are always connected
to the service battery. Please note: by connecting consumers directly to the service battery, the
SMARTPASS 120T can no longer protect against deep discharge.
• Assigning current source priority
When the alternator is running, the SMARTPASS 120T will supply consumers with current directly
from the starter battery (alternator). This feature will maximize the charging efficiency when a
D250T is used in the system as no consumers will take any power from service battery.
• Dynamic overcurrent protection
SMARTPASS 120T can handle temporary inputs and outputs of up to 350A for fast charging. It
has an overcurrent protection and internal temperature monitoring to protect electronic circuits and
keep the electronics within safe operation.
• Smart Alternator
SMARTPASS 120T can also be used when vehicle is equipped with a smart alternator (with
variable charging voltage). This is activated by connecting the red smart alternator cable
according to the instruction in this manual.
• Overvoltage protection
The Alternator input is electronically overvoltage protected. If voltage from alternator is too high
SMARTPASS 120T will turn off the connection to service battery and consumers.
• Service battery temperature protection
SMARTPASS 120T is equipped with a temperature sensor to be attached to the service battery
pack. This protects the battery by switching off the connection between starter battery and service
battery if the service battery temperature is too high, i.e. not allowing charge from the alternator to
the service battery.
• Starter battery trickle charging
When the service battery voltage is higher than the starter battery, the SMARTPASS 120T will
trickle charges the starter battery by periodically connecting the service battery output to the
alternator input. This can be helpful to compensate for the self-discharge of the starter battery. It
is especially useful if another power source is feeding the service battery, for example a battery
charger.
• Compatible with D250T
To get the optimal dual battery management system the SMARTPASS 120T should be combined
with D250T DC-DC charger to get a stable, reliable and optimized charging system. D250T and
SMARTPASS 120T can together charge the service battery and provide the consumers up to
130A of power.
• Overvoltage protection
Alternator input is electronically overvoltage protected. If voltage from the alternator is too high
the SMARTPASS 120T will disconnect the connection to the service battery and consumers.
When voltage is back within the normal range SMARTPASS 120T will automatically open the
connections.
SMARTPASS 120T
SMARTPASS 120T
