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

Redarc Smart Start Battery Isolator - 12 Volt - 200 Amp

Part Number: 331-SBI212
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$280.00
Retail:$529.26
You Save: $249.26
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This 200-amp dual-battery isolator pulls power from your start battery to charge your auxiliary battery. Isolator switches off to prevent dead battery if start battery voltage drops too low. Compact design for versatile mounting. 1-800-940-8924 to order Redarc battery charger part number 331-SBI212 or order online at etrailer.com. Free expert support on all Redarc products. Great prices and Fastest Shipping for Redarc Smart Start Battery Isolator - 12 Volt - 200 Amp. Battery Charger reviews from real customers.
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  • Reviews (24)
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Redarc Battery Charger - 331-SBI212

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

This 200-amp dual-battery isolator pulls power from your start battery to charge your auxiliary battery. Isolator switches off to prevent dead battery if start battery voltage drops too low. Compact design for versatile mounting.


Features:

  • Battery isolator protects start battery from auxiliary drain in multiple battery setups
    • Transfers charge from start battery to auxiliary battery once start battery gains charge from alternator
    • Stops charge transfer if start battery voltage drops too low, preventing excessive discharge
  • 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
  • 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


With this dual-battery isolator, you can transfer power from your start battery to an auxiliary battery without draining your start battery. As long as your vehicle is on and the alternator is supplying power to the start battery, the Smart Start will transfer some of that power to your auxiliary battery. When your vehicle is shut off, the isolator will separate its connection and stop pulling power. This ensures that your start battery is protected so that no matter how weak your auxiliary battery becomes, your start battery won't be left flat. As a result, 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.


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 Battery Isolator Wiring Diagram



SBI212 REDARC Smart Start Battery Isolator - 12 Volt - 200 Amp

Installation Details 331-SBI212 Installation instructions


California residents: click here


Customer Satisfaction Score:


Customer Reviews

Redarc Smart Start Battery Isolator - 12 Volt - 200 Amp - 331-SBI212

Average Customer Rating:  5.0 out of 5 stars   (24 Customer Reviews)

This 200-amp dual-battery isolator pulls power from your start battery to charge your auxiliary battery. Isolator switches off to prevent dead battery if start battery voltage drops too low. Compact design for versatile mounting.

by:

I put this on a 2013 chevy HD 4 wheel drive and it works very well.
I have my main battery went bad and I open the hood and flip the switch and the
accessory battery started my truck. thank you for having good products for us to buy
when we need something,

Tommy R.

9/2/2021

It is still working very well and if I was to buy another truck i would put one on it.



by:

Outstanding product, satisfying results and top notch quality.



by:

works perfect



by:

Really like this isolator. Replaced two Cole-Hersey Isolators that failed prematurely in a Class C RV after only 11 and 3 months. Second photo shows Cole-Hersey replaced by Redarc shown in last picture



by:

I didn’t know this product existed. I don’t know why RV manufactures don’t install these when they build the motor homes. Always a pleasure doing business with e-trailer.



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.








by:

With a flip of a switch from the drivers set, I'm able to re-charge the coach batteries from the vehicle battery via this Redarc Battery Charger while driving to the next camping adventure.



by:

I use this in my Jeep to keep my second battery for accessories charged and ready. After a year of having it installed I couldn’t be happier with the product. I have spoken with the folks out in Australia at Redarc and find them to be very awesome to speak too.



by:

Wonderful instructions, plenty of wire, and a very good product. Will try and update this review in a year! Thanks for putting the pieces together. All solid quality, 60 amp fuses, and neatly trimmed heavy gauged wire.



by:

This is a great product. I use it to run my fridge in my Jeep to keep the second battery charged.



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.



by:

I have used these redarcs a couple of times with great success but having this shipped in a very timely fashion from etrailer is fantastic!



by:

works great would but anain



by:

It's for my 04 Jeep Wrangler TJ.



by:

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



by:

works prefect



by:

Works great



by:

Awesome product, easy to install and come with all parts needed to install second battery!!!



by:

Got exactly what I needed and very fast.



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Great product, great service.



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See what our Experts say about this Redarc Battery Charger

  • Recommended Battery Isolator for Ram ProMaster with 220 Amp Alternator
    In regards to battery isolators, they should be rated at or close to the changing amperage rating of your alternator. They don't really need to exceed this as it's very unlikely your alternator will ever reach its max charging amperage therefore, I recommend the Redarc Smart Start Battery Isolator part # 331-SBI212 which is rated at 200 amps and the highest we offer. That said, these don't work with lithium batteries and the highest rated battery isolator we do offer for this is the Redarc...
    view full answer...
  • Which Redarc Smart Start Battery Isolator Would Replace Sure Power 1315-200
    The equivalent would be the Redarc Smart Start Battery Isolator # 331-SBI212D. The dual sensing is the equivalent to the bidirectional functionality on your Sure Power 1315-200. This will allow you to transfer charge from either your start battery or your auxiliary battery to keep both batteries in your setup charged.
    view full answer...
  • Recommended Battery Isolator for 220 Amp Alternator in Class A Motorhome
    In regards to battery isolators, they should be rated at or close to the changing amperage rating of your alternator. They don't really need to exceed this as it's very unlikely your alternator will ever reach its max charging amperage. I recommend the Redarc Smart Start Battery Isolator part # 331-SBI212 which is rated at 200 amps. This isolator has a ton of great features like the ability to connect to an LED (not included) that can be mounted in your cab for easy viewing of diagnostics....
    view full answer...
  • What is the Difference Between Redarc Battery Isolator # 331-SBI212 and # 331-SBI212D
    The primary difference between the Redarc Smart Start Battery Isolator # 331-SBI212 and # 331-SBI212D is that the Isolator # 331-SBI212D is actually a dual-sensing battery isolator, which means it can transfer power in either direction when connected in-line with 2 batteries. When connected in this way with 2 batteries, 1 that is charged by your alternator and another that is connected to an outside source, it will transfer power in either direction to keep both batteries charged. The...
    view full answer...
  • Recommended Battery Isolator for a 2014 GMC Sierra 1500 w/ a 150 amp Alternator
    Since your 2014 GMC Sierra 1500 has a 150 amp alternator, I recommend the Redarc Smart Start Battery Isolator item # 331-SBI212 which is rated at 200 amps. You always want to go with an isolator that is rated for higher amps then your alternator to prevent damage. With the Redarc Smart Start Battery Isolator item # 331-SBI212, you can transfer power from your truck battery to your auxiliary batteries without draining your battery. As long as your Sierra is on and the alternator is supplying...
    view full answer...
  • Will the Redarc Smart Start Battery Isolator Work with Three 100 Amp BAtteries in the Battery Bank
    The Redarc Smart Start Battery Isolator part # 331-SBI212 will work great for your application as long as you have your 3 100 Amp deep cycle batteries wired in parallel and it is 12 volts. If your batteries are wired in series and output 36 volts it is not compatible. The size of the battery bank does not effect the isolator because it is past the isolator in the path. The 200 Amp rating means that it is rated for 200 amps passing through it from the vehicle into the battery bank.
    view full answer...
  • Battery Isolator to Use on Promaster Van with 220 Amp Battery with 100 Amp Auxiliary Batteries
    For a larger alternator like what you have we have the Redarc Smart Start Battery Isolator # 331-SBI212 which is rated for up to 200 amps. With this battery isolator, you can transfer power from your start battery to an auxiliary battery without draining your start battery. As long as your vehicle is on and the alternator is supplying power to the start battery, the isolator will transfer some of that power to your auxiliary battery. When your vehicle is shut off, the isolator will separate...
    view full answer...
  • Recommended Battery Isolator For 1996 Dodge Ram Van With 120 Amp Alternator
    Since your 1996 Dodge Ram Van with the 3.9L engine has a 120 amp alternator you will need the Redarc Smart Start Battery Isolator # 331-SBI212 with a 200 amp rating, as the # DW08771 you were looking at is only compatible with alternators that have an amp rating of under 120 amps. The # 331-SBI212 will get wired between your start battery and auxiliary battery allowing both batteries to stay charged, while keeping your start battery from being drained to the point that it cannot run your...
    view full answer...

Do you have a question about this Battery Charger?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
Kristina F
Employee Brian T
Written by:
Brian T

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