Date: 2020-10-01
Version: 1.0
Title: SMARTPASS 120S with Charger at Service battery
Starter battery:
A start battery should never be deeply discharged and should
be capable of delivering high current for a short period of
time.
The starter battery should be a Lead Acid battery designed for
automotive applications. This does not affect the chemistry
chosen for the Service battery
Service battery:
Also known as secondary battery, it should be of the type
deep cycle batteries. The size should be 20Ah to 300Ah or
even up to 800Ah with SMARTPASS 120S installed.
You can install several batteries in parallel in order to increase
the total capacity (Ah) of your service battery bank.
If possible, the service battery should be installed in a well-
ventilated space away from the engine bay, unless the battery
is designed for it.
Install the service battery as close as possible to the charger,
preferably not further away than 2m, which is the length of
temperature sensor cable.
Temperature sensor:
For D250SE and SMARTPASS 120S the temperature sensor
ensures that the battery is only charged within its
temperature range and helps detect a damaged battery that is
overheating. In the latter case the charger will stop charging
the battery and indicate fault. D250SE also uses the
temperature senor to enable temperature regulation of the
charge voltage
Fuses
:
We recommend that all cables directly attached to a battery
holds a fuse as close as possible to the battery in order to
protect the cable.
See manual for fuse size.
SMARTPASS 120S:
Is a smart combination of relays (actually MOSFETS) that
connects starter and service batteries. This enables current
from your alternator to charge both batteries.
The SMARTPASS 120S will not control the voltage applied to
the service battery. For that you need a D250SE installed in
parallel.
The current through the SMARTPASS 120S to a service battery
depends on the alternator output voltage, cable length/
dimension and the charge acceptance of your battery. The
max continuous current is 120A.
Start assistance.
SMARTPASS 120S automatically connects the service and
starter battery, if the starter battery on its own is unable to
start the engine. After the start assistance function
has been activated, SMARTPASS 120S will display a fault
indication that remains until starting has been achieved
without the use of the start assistance function.
Install according to instruction manual.
Consumers:
Consumers (max 80A continuously) should be connected to
the consumer output terminal of the SMARTPASS 120S. If the
service battery voltage becomes critically low, the consumer
output terminal is deactivated in order to protect the service
battery, i.e. under voltage protection.
Consumers that should not be affected by this under voltage
protection should be connected directly to your service
battery, typically high priority consumers like VHF radio.
Consumers connected to the consumer output receives
current from the alternator instead of the service battery
during driving. This makes the charging of the service battery
faster and if the battery is fully charged it is put in a rest state,
which increases the lifetime of the service battery.
Cables
:
For the best possible functionality follow the instructions in
the manual regarding cable dimensions and make sure the
cables are as short as possible in order to minimize voltage
drops.
All cables should be firmly mounted and preferably in a cable
protection tube minimizing wear and tear from the vibrations
in your vehicle.
Busbars can be used to make the installation neat and tidy
and the use of tubular ring terminals (size M8) properly
crimped will reduce unnecessary resistance in the
connections.
Note, the weaker cable recommendation to the negative
terminal (D250SE) is chosen since it only carries current to the
control electronics, not the charge current. The latter will flow
through earth, which is connected to the negative terminal of
your battery
