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Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp

Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp

Item # 331-SBI212D
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331-SBI212D - DC to DC Redarc Battery Chargers
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Connect this isolator in-line with 2 batteries - 1 that is charged by your alternator and another that connects to an outside source - and it will transfer power in either direction to keep both batteries charged. Shuts off if battery drops to 12.7V. Call 800-298-8924 to order Redarc battery chargers part number 331-SBI212D or order online at etrailer.com. Free expert support on all Redarc products. Guaranteed Lowest Price and Fastest Shipping for Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp. Battery Chargers reviews from real customers.
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  • Reviews (3)
  • Q & A (8)
  • Videos (2)
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Redarc Battery Chargers - 331-SBI212D

  • Battery Isolators
  • Redarc
  • Vehicle Battery to Auxiliary Battery
  • 12V
  • DC to DC

Connect this isolator in-line with 2 batteries - 1 that is charged by your alternator and another that connects to an outside source - and it will transfer power in either direction to keep both batteries charged. Shuts off if battery drops to 12.7V.


Features:

  • Dual-sensing battery isolator connects in-line with 2 batteries and transfers power in either direction
    • Transfers charge from start battery to auxiliary battery once start battery gains charge from alternator
    • Pulls power from auxiliary battery that is connected to outside power source to charge start battery
  • Isolator function stops power transfer from the charging battery if its voltage drops too low
    • Prevents excessive discharge and dead battery
  • Override wire allows for emergency starts and simple fault detection
    • Attach to a switch (sold separately) to manually reverse charge and jump-start a dead start battery
    • Connect to an LED (not included) that can be mounted in your cab for easy viewing of diagnostics
  • Silver contact points ensure long life and corrosion resistance
  • Durable housing protects sensitive electronics
  • Compact design allows for versatile installation
    • Mount the isolator in a convenient location near the start battery
    • 4-Gauge cables, fuses, and connectors sold separately
  • Made in Australia


Specs:

  • Application: vehicles with standard or temperature-compensating alternators
  • Maximum continuous current: 200 amps
    • Standby current: less than 5 mA
  • Output connection: 12V DC
  • Overall dimensions: 3-15/16" long x 3-3/4" wide x 3-1/2" tall
  • 2-Year warranty


This dual-sensing battery isolator can transfer charge from either your start battery or your auxiliary battery to keep both batteries in your setup charged. Turn on your vehicle, and once the alternator begins to supply power to the start battery, the Smart Start will transfer some of that power to your auxiliary battery. If your start battery is low, make sure that your auxiliary battery is connected to an outside power source, like a solar panel, and it can transfer some of its charge to the start battery. The isolator function of this system will stop the charge transfer to and from either battery if the charging battery's voltage drops too low. This ensures that both batteries are protected so that you can venture out without the fear of running into a dead battery.


Parallel Charging for Optimal Functioning

REDARC Smart Start Dual Sensing Battery Isolator Parallel Charging Setup Diagram

The Smart Start connects in-line between your start battery and the auxiliary battery. This way it can pull the charge directly from the battery instead of pulling from an outside source, like your vehicle's alternator. This method of charging is called parallel charging.


REDARC Smart Start Dual Sensing Battery Isolator Priority Charging Setup Diagram

Most other battery isolators on the market use priority charging. In a typical priority charging setup, the alternator provides charge to either the start battery or the auxiliary battery, but not to both simultaneously. This can leave both batteries underpowered. With parallel charging, the power is drawn directly from the start battery, which removes stress on the alternator because it doesn't have to manage both batteries separately. This streamline connection of the Smart Start to the start battery also prevents potentially damaging voltage surges that can occur when a priority charger switches over between batteries.


2-Way Charging

Dual-sensing technology allows this Smart Start isolator to monitor the voltage of both the start battery and the auxiliary battery. If the auxiliary battery is connected to an external power source, then the Smart Start will recognize when the auxiliary battery reaches a full charge (13.2V) and it will redirect the current to provide a charge to the start battery. This allows you to use a solar panel (sold separately) or an additional battery charger (sold separately) to charge not only the auxiliary battery, but also the start battery.


Additional Features

The blue override wire attached to the Smart Start allows for additional features, like the Start Assist function. This function allows you to jump-start a dead start battery using the auxiliary battery. Just connect the blue wire to a push-button switch (sold separately) to create a bridge of power from the auxiliary battery to your dead battery. Great for those mornings when you leave the radio on too long or forget to close the vehicle door.


You can also connect the blue wire to an LED (not included) to create an in-cab fault indicator. There is an internal LED on the unit itself that provides fault detection. This system communicates by causing the LED to flash a certain number of times to indicate errors. For example, 2 flashes signals over-voltage, and 3 flashes signals a voltage drop or excessive current draw fault. By connecting an additional LED to the blue wire, and running that up to your cab, you can more quickly assess these faults than if you had to peer into your engine compartment to see the light on the unit itself.


For assistance in wiring the Smart Start to include these optional features, please refer to the diagrams below:


Redarc Smart Start Battery Isolator Optional Wiring

Compact Design for Versatile Mounting

Mount the battery isolator in a location near your vehicle's start battery. The compact design of the unit allows you to have a good deal of flexibility when selecting a mounting location. A couple of places to consider would be in front of the radiator or behind the headlight assembly. You will need to make sure that the location you choose is not exposed directly to engine heat.


Once the unit is securely mounted, attach each battery to one of the terminals on the Smart Start. It is important to use the proper gauge wire for your particular application. If the cable length that you need is under 10', make sure that the wire gauge is 4 AWG. If you will be using between 10' and 20' of cable, you will want to select a thicker 3-gauge wire. To prevent damage from overload and short circuits, you will want to use properly rated fuses or circuit breakers (sold separately) to ensure that current is efficiently transferred.


For assistance in properly wiring the Smart Start, please refer to the diagram below:


REDARC Smart Start Dual Sensing Battery Isolator Wirisng Diagram



SBI212D REDARC Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp

Installation Details 331-SBI212D Installation instructions


California residents: click here


Video of Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Redarc Smart Start Battery Isolator Manufacturer Demo

The Smart Battery Isolator, or SBI, allows your auxiliary battery to charge from the alternator while the vehicle is running, and protect the start battery from discharging when the engine is off. It can also be used in conjunction with an in-vehicle battery charger, or BCDC, to allow the start battery to be jump-started from the auxiliary battery in the event that the start battery is discharged or fails.This product works best with standard alternators, not with smart or variable alternatives. In a dual battery set up where one battery is used as a starter battery to operate the vehicle and one as a secondary to run electrical devices, the SBI ensures your start battery doesn't run flat when you use your secondary battery, while the engine is turned off.When the engine is turned off, and therefore the alternator is no longer running, the start battery will drop below 12.7 volts and the SBI will disengage the secondary battery. This will stop any loads connected to the auxiliary battery from draining the start battery.The Smart Battery Isolator comes in 12 and 24 volt, both 100 and 200 amp models, and a dual sensing range is also available. You can pair the Smart Battery Isolator with in-vehicle battery chargers, which will allow the start battery to be jump-started from the auxiliary battery in the event that the start battery is discharged or fails.When programmed as a low disconnect isolator, it can also be paired with battery management systems to protect the auxiliary battery from excessive discharge. The Smart Battery Isolator is ideal for four-by-fours, motor homes, marine craft, and heavy industrial vehicles.(silence).


Customer Reviews

Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 200 Amp - 331-SBI212D

Average Customer Rating:  5.0 out of 5 stars   (3 Customer Reviews)

Connect this isolator in-line with 2 batteries - 1 that is charged by your alternator and another that connects to an outside source - and it will transfer power in either direction to keep both batteries charged. Shuts off if battery drops to 12.7V.

- 331-SBI212D
by:

I purchased the Redarc 331-SB1212D battery charger during the 2018 Christmas holiday season, it shipped with good efforts from etrailer. It is installed on a 2009 Chevy 5500 diesel powered cab and chassis truck , 2 on-board factory batteries in combination with add on 2 battery auxiliary bank, chassis mounted. I have extra heavy auxiliary power leads wire loom insulated routed with 350 amp Anderson connectors located at the ends , 1 lead to the front bumper , 2 leads to the rear bumper and a small 2/0 lead routed to the cab with 175amp Anderson connector for a 650 watt inverter. This application provides jumpstart service and remote power for dump trailer and 3000watt inverter power . This system has an additional provision to combine all batteries for heavy winching or sub zeros self jumpstart . My installer provided the additional switching to Redarc design specification. 734539



- 331-SBI212D
by:

Product works as expected and I would recommend it to anybody needing a product like this. 671485



- 331-SBI212D
by:

This bad boy had me at dual sensing, and 200 amps is exactly what I need for my beefy house battery bank. One knock might be a short ground wire, but otherwise great product. 460888


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Info for this part was:

Edited by:
Lindsey S
Installed by:
Jeff D
Expert Research:
Jameson C
Video Edited:
Chris R
Written by:
Brian T
Updated by:
Kristina F

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