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Dual Battery Isolator Kit 12V - 140 Amp Voltage Sensitive Relay (VSR) for Dual Battery Setup - Automatic Disconnect Switch for Car, Truck, RV, UTV, ATV, Marine

  • Based on 1,666 reviews
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Availability: In Stock.
Fulfilled by Amazon

Arrives Sep 8 – Sep 9
Order within 11 hours and 37 minutes
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Size: 140 AMP ATV/RV


Features

  • Advanced Dual Battery Isolator 12V Kit Designed for superior performance, this dual battery kit ensures efficient power distribution between two batteries without voltage drops. Unlike traditional battery isolator diodes, this automatic disconnect switch eliminates power loss while maintaining a seamless connection between your primary and auxiliary power sources. Compact at 2.6 x 2.6 x 2, its perfect for under-hood installations or as part of a battery relocation kit.
  • Smart Voltage Sensitive Relay (VSR) for Optimal Charging Featuring a 12V dual battery wiring kit, this system automatically activates at 13.3V and disengages at 12.8V, ensuring your starting battery remains fully charged. Whether you're installing a marine dual battery kit for your boat, a dual battery kit for truck applications, or need a battery isolator 12V kit for off-grid power, this setup prevents battery drain and guarantees reliable performance.
  • Built for Extreme Conditions & Rugged Durability Engineered for off-road adventures, marine use, and daily driving, this dual battery isolator kit is IP65-rated for water, dust, and vibration resistance. Its solid-state design ensures durability, making it an excellent choice for automotive, RV, UTV, and marine battery isolator needs. Whether battling tough trails or navigating open waters, count on this dual battery wiring kit to provide uninterrupted power.
  • Complete Dual Battery Wiring Kit for Easy DIY Installation No complicated setup required! This battery isolator kit includes a 140A voltage sensitive relay, 12" red power cable, 24 red power cable, 12" black ground cable, tinned copper lugs, marine-grade brass terminals, heat shrink tubing, cable ties, and an easy-to-follow install guide. No complex wiring or diodes requiredthis is a plug-and-play solution for any 12V dual battery wiring setup.
  • Trusted Performance with Warranty & Money-Back Guarantee Every dual battery kit by KeyLine Chargers is backed by a 12-month industry-leading warranty. If youre not 100% satisfied with your purchase, take advantage of our 30-day money-back guaranteeno questions asked! Drive with confidence knowing you have a premium battery isolator 12V kit keeping your power system running at full capacity.

Is Discontinued By Manufacturer ‏ : ‎ No


Product Dimensions ‏ : ‎ 1.97 x 1.97 x 1.97 inches; 8 ounces


Item model number ‏ : ‎ Iso-Pro140


Date First Available ‏ : ‎ April 28, 2015


Manufacturer ‏ : ‎ KeyLine Chargers


Best Sellers Rank: #16,708 in Automotive (See Top 100 in Automotive) #1 in Automotive Replacement Battery Relocation Kits #1,679 in Automotive Replacement Electrical System Relays


#1 in Automotive Replacement Battery Relocation Kits:


#1,679 in Automotive Replacement Electrical System Relays:


Customer Reviews: 4.5 4.5 out of 5 stars 1,666 ratings


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sep 8 – Sep 9

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Leasing options through Acima may also be available during checkout.

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Top Amazon Reviews


  • It works
Size: 140 AMP Kit
Installed this in a full size 2010 GMC Sierra with a marine battery as the second. It was easy enough to install and works fine. Everything was included in the kit. The only thing I did different was soldered the eyelets onto the wire instead of trying to crimp them. That can be done with a small butane torch to heat up the eyelets and just feed the solder in until it's bonded. Provides a better electrical contact than crimping. ... show more
Reviewed in the United States on April 20, 2023 by Jeddidiah Stolzfus

  • Does the job at 1/3 the cost
Size: 140 AMP Isolator
Had a Redarc that failed just when I needed it most (in the middle of nowhere in a foreign country with no expedite delivery) This unit does same job, 1/3rd of cost so you can carry a spare and still save some money. Easy to install and functions as it supposed to so far.
Reviewed in the United States on December 24, 2023 by Calin

  • Protect your Investment
Size: 140 AMP Kit
Used it 2 add cranking power from multiple batteries. Works like a Charm!
Reviewed in the United States on March 23, 2024 by jeffrey l blancett

  • Don’t plan on using their red cable.
Size: 140 AMP Kit
If the power cable that came with the kit wasn’t so cheap I would give it 5 stars. I updated the batteries behind the seat of my 84 Toyota pickup rock crawler with this kit. It’s a good quality product until you get to the red cable they give you to hook up the batteries. It’s not nickel plated solid core, and it has very few strands. The insulation on the wire is more like hard plastic than a soft rubber. It’s a PITA to strip the insulation off the cable, and it just feels, like, really.....Chinese in origin. I’ve been doing things like this for over 30 years and this the first cable that was so unpleasant to work with that the whole time I just kept saying things like “Where did they get this wire?”, and “This is the worst wire I’ve ever seen!”..... Aside from that, everything else in the kit was good. I also think the mounting “kit” was cheap though. I didn’t use anything from the little duplicate bag. The heat shrink is cheap, (not extra thick) the screws are not stainless steel, etc. But if you ignore all the “accessories”, the unit itself is fantastic. ... show more
Reviewed in the United States on May 1, 2021 by 55reasons 55reasons

  • It works
Size: 300 AMP Kit
Installed it 4 months ago as a bank up battery for my system and aux lights. Works as it should and works flawlessly.
Reviewed in the United States on May 29, 2024 by Rojo

  • Great isolator. Works great in 2016 Polaris Ranger 900-5 Crew.
Size: 140 AMP ATV/RV
Ive had this in my Polaris ranger 2016 900-5 crew, for about 8 months. I have 2, 1200 Odyssey batteries installed. This thing works like a champ. It passes the charge to the battery that needs it the most. I tax my system more than most people ever will, and this isolator does more than I need it to. You have to understand your setup and how it all charges or you wont understand how this thing works. I have 2, 54in curved 4D light bars, and 2, 50in curved 4D light bars, along with 2, 7in light bars, and in cab, mulit color lights. I can run all night on my setup. I can hunt 3,000+ acres, for over 8 hours without any issues. I can hear the isolator clicking back and forth, and I can watch my voltage move around. I never drop under 10 volts, on a full load, and that is after all night of hunting. It would of been nice to have longer and better neg and pos. cables, but because of all the other work done to the Ranger, I did have better cable laying around. Others will not have the same luck. So a tip to the seller. Just give the better, longer cables. It wont cost you that much more, and honestly even if it does, I would of paid to have the better cables. Outside of that, I didn't buy this for the cables. I needed the isolator, and it is great quality, and works flawlessly. ... show more
Reviewed in the United States on June 19, 2017 by Brantley Hickerson

  • The best solution for battery isolation
Size: 140 AMP Isolator
I was looking for a good quality relay to be used in my Chevy truck to isolate an auxiliary battery. My OEM relay failed, but it was 30 years old. The auxiliary battery is used as one of two batteries for my pickup camper - one is in the engine compartment and the other in the camper. I tried three different isolation relays, two of which looked pretty good. The Stinger SGP32 was the best, since it drew the least amount of current when activated. But then further searching brought me to this relay, which works with a clever design using voltage rather than just an ignition circuit. I ordered one of these and the Jaycorp Smart Battery Isolator, which also looked good. When I received them from amazon I found them to be almost identical in design, and upon bench testing they both worked perfectly. I ended up keeping the Keyline product and returning the Jaycorp relay, but only because I liked the small red LED a bit better than the bright blue LED on the Jaycorp relay. Either relay looks to be a great solution for battery isolation. If this Keyline product proves reliable, I'll be a very happy camper! Update 8/3/21: This isolator has worked perfectly since I installed it. A 5 star product! ... show more
Reviewed in the United States on September 4, 2019 by Ray R. Kawal

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