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Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 100 Amp

Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 100 Amp

Item # 331-SBI12D
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331-SBI12D - Vehicle Battery to Auxiliary Battery Redarc Battery Isolators
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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 charger part number 331-SBI12D 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 - 100 Amp. Battery Charger reviews from real customers.
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  • Reviews (1)
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Redarc Battery Charger - 331-SBI12D

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

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
    • 8-Gauge cables, fuses, and connectors sold separately
  • Made in Australia


Specs:

  • Application: vehicles with standard or temperature-compensating alternators
  • Maximum continuous current: 100 amps
    • Standby current: less than 5 mA
  • Output connection: 12V DC
  • Overall dimensions: 3-1/8" long x 2-15/16" wide x 2-1/2" 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 8 AWG. If you will be using between 10' and 20' of cable, you will want to select a thicker 6-gauge wire. To prevent damage from overload and short circuits, you will want to use MIDI fuses (331-FK100 - 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



SBI12D REDARC Smart Start Battery Isolator - Dual Sensing - 12 Volt - 100 Amp

Installation Details 331-SBI12D Installation instructions


California residents: click here



Customer Reviews

Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 100 Amp - 331-SBI12D

Average Customer Rating:  5.0 out of 5 stars   (1 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-SBI12D
by:

works great would but anain 686744


Comments
works perfect would buy again
David - 08/14/2020

97259
1
1

Ask the Experts about this Redarc Battery Charger

  • Should Batteries be Connected of Redarc Smart Start Battery Isolator
    Thank you for your purchase of the Redarc Smart Start Battery Isolator # 331-SBI12D from etrailer. In regards to the isolator, the two batteries would not be connected. Like you mentioned, the negative posts of each batteries would be grounded, as stated in the linked directions. I have added links to video reviews for you to check out as well.
    view full answer...
  • Are Fuses Needed When Using Redarc Smart Start Battery Isolator to Charge Secondary Battery
    If you're using the Redarc Smart Start Battery Isolator # 331-SBI12D between the start battery and your auxiliary battery (which is what I recommend for transferring the charge back and forth) then you will want to add a couple 100-amp MIDI fuses in-line before and after the isolator. These fuses can be found in the Redarc Fuse Kit # 331-FK100, which also comes with the fuse holders, hardware, and 4 cable crimp lugs. I have attached an image to assist. The Smart Start Battery Isolator...
    view full answer...
  • Redarc Smart Start Battery Isolator Recommendation for 150 Amp/Hour Alternator
    Since the alternator is 150 amp/hours you'd want the Redarc Smart Start Battery Isolator # 331-SBI212D which is rated for 200 amps. The 100 amp kit would be too low rated for your alternator.
    view full answer...
  • Using a Redarc Battery Isolator to Add a Second Battery to a 2009 Chevy Suburban 2500
    Yes, you can use the Redarc Smart Start Battery Isolator # 331-SBI12D on your 2009 Chevy Suburban once you add a second battery. Basically this charger will install between the two batteries. Your regular battery will get a charge from the vehicle alternator and the 2 batteries will "feed" each other as needed. You may also consider adding the TorkLift HiddenPower Under-Vehicle Battery Mount with Battery Box # TLA7730 which was designed for Chevy trucks but could be used with your Suburban...
    view full answer...
  • Can Redarc In-Vehicle BCDC Battery Charger be Used to Jump Start Battery
    In addition to the Redarc In-Vehicle BCDC Battery Charger # 331-BCDC1225D you need to use a Redarc Smart Start Battery Isolator. I recommend using the Battery Isolator with Wiring Kit # 331-SBI12KIT if you don't already have the fuse kit, or part # 331-SBI12D if you do already have the fuse kit. With the isolator installed you can then connect a push-button into your system to help jump your start battery.
    view full answer...
  • Redarc Auxiliary Battery Isolator for 1992 Jeep Comanche with 90 Amp Alternator
    You basically just need to go with the Redarc Smart Start Battery isolator that has at least the amount of amperage required that your alternator puts out so for a 90 amp alternator you'd want the part # 331-SBI12D.
    view full answer...
  • Parts Needed to Add Second Battery and 12V Outlets to Bed of Chevy Silverado
    To add an additional battery in your 2002 Chevy Silverado I recommend adding the Redarc Smart Start Isolator # 331-SBI12D in-line between the truck's start battery and the auxiliary battery. This will transfer power in either direction to maintain the charge on both batteries. Then to add 12V outlets to the bed you can use the Roadmaster # RM-9332 and run the wiring up to the Silverado's battery using 12 gauge wire # 12-1-1 (sold by the foot), butt connectors # 05732-2, a 12 gauge fuse...
    view full answer...
  • Recommended Battery Isolator for Diesel Truck Start and Nearly Dead Trailer Batteries
    With the Tow Ready Battery Isolation Solenoid # TR118665 you very likely could have the issue you are describing with a diesel truck if your accessory is connected to your ignition. If you want an isolator that will ensure you will be able to start your diesel truck a much better option is the Redarc Smart Start Battery Isolator - Dual Sensing - 12 Volt - 100 Amp # 331-SBI12D. This is designed for the dual battery systems of most diesel applications and will give you parallel charging....
    view full answer...
  • Recommendation for Charging Five Lawn Equipment Batteries on Trailer During Stops
    Your best and most economical option for being able to charge up the batteries for each of your crews during stops or lunches may be to just equip each trailer with a generator like etrailer.com 3,200 Watt # 333-0003. This generator will provide you with two 120V 20-amp power outlets to charge your batteries. It features an electric-start engine with a handheld remote and has a continuous run time at 1/4 load of up to 9 hours. Whether this will work well will also depend a bit on just how...
    view full answer...




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Info for this part was:

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

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