Dual Battery Isolator Kit 12V - 140 Amp Voltage Sensitive Relay (VSR) for Dual Battery Setup
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Availability:
In Stock.
Arrives
Tuesday, Apr 14
Size: 140 AMP Kit
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 (1) 140 Amp voltage sensitive relay, (1) 20-ft red power cable, (1) 2-ft black ground cable, (2) positive marine-type brass battery terminals, (1) negative brass terminal, tinned copper lugs, heat shrink tubing, cable ties, and step-by-step instructions. Perfect for DIYers of all skill levelsjust connect the power wire in, power wire out, and youre ready to go!
- 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.
Product Dimensions: 2 x 2.6 x 2.6 inches
Item Weight: 8 ounces
Manufacturer: KeyLine Chargers
Item model number: Iso-Pro140DBK
Is Discontinued By Manufacturer: No
Date First Available: April 28, 2015
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Apr 14
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.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Size: 140 AMP Kit
It works perfect I just put it on a big truck to have a backup battery for a power inverter that is installed for power tools and it works perfectly easy to install the quality looks pretty good includes everything you need and your battery terminals you may have to fill the hole biggers on the tips but other than that everything fits good
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Reviewed in the United States on April 6, 2025 by tcg
Size: 140 AMP Kit
Thus far: Install was easy enough, especially if you have experience with audio equipment. Please ignore my lazy cable management (i haven't completed the build) Product cuts in when alternator is on and cuts out at 12.8v like it says (tested with multimeter). If you do what i did you will need 1x more 6 (couldn't find 7) gauge battery terminal connectors. You will also need more heat shrink tube, just buy a length of it at 6 gauge. Tools you will need: Rachet set (varied sizes for bolts/nuts) Razor blade (stripping 7 gauge wire (or if you're fancy you can buy a fancy smancy stripper)) Some kind of Wire cutter, i used a simple wire cutter. Crimp tool (i used wire cutter ^) Heat source for heat shrink (i used propane torch) Multi meter (for testing grounds and voltages) Anti Seize for connections (not necessary but very good investment) 12v Battery (preferably deep cycle with 100Ah) 12v Battery clamps, (see in pic 1/3 in the center of battery) was like $6 at O'Rielly's Auto. Flat head for prying those snap cap thingys. Make/Model: 2014 Chevy Silverado 1500 LT Battery: SuperStart 27 ($92 O'Reilly's) My Install: I took the 20ft cable and split it, running one for positive and one for negative to connect to the starter battery. I took the included 2ft Ground battery and grounded to the engine block (see image 2) Cut more of a hole than prescribed in the directions for the Isolator housing for the entry/exit cable holes (^You'll see why) I took a cylinder sanding wheel with a dremel tool to sand paint away from part of the cab near the isolator for the isolator's 16-ish gauge ground and used a machine bolt for the fasten. Used battery clamp/hook system to fasten battery to tray (forget about the chevy clamp, this is better) Will update every few months
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Reviewed in the United States on January 24, 2020 by KirbytheDiver
Size: 140 AMP Kit
This battery isolater works great! Easy to install once you figure out where you will place it. I had to build a small shelf that it sits on for my install. All components needed are in the kit no guessing about wires gauges, connector sizes, etc. The hardest part is figuring out where you will mount it in your particular vehicle. Attached are pictures of my install location and wire runs on my 2017 Toyota Tacoma. The only thing i run off my secondary battery is a 12 fridge/Freezer (Costaway 54qt from Amazon) on my overland trips. I am not a mechanic or electrician, instruction are clear and straight forward, just follow the directions, you can install this. There are also tons of videos on you tube if you are not sure.
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Reviewed in the United States on July 20, 2019 by Mark from Texas
Size: 140 AMP Kit
Installed on a Polaris Ranger 2015 Crew-6 EPS Installed in conjunction with Odyssey PC925 Automotive and LTV Battery Odyssey L Terminal Adapter MICTUNING LED Digital Double Voltmeter, Round Panel Voltage Monitor Blue for Car Pickup RV Truck Dual Battery Pack Works exactly as designed! Fairly easy to install, but a change would make installation much easier - I do not have a crimper for battery terminal lugs and I didn't want to buy one to make two crimps, so I soldered the terminal lugs. The battery terminal lugs included with the kit have an opening on the ring end which makes it rather difficult to solder the terminals to the wire as the solder leaks out. If you don't have a crimper, then consider picking up these to replace the ones in the kit (you will need to verify the hole diameter for your battery terminals) Pico 4239C 4 AWG Battery Cable 3/8" Tubular Lug Ring / Eye Terminals 15 Per Package Where I mounted the isolator I could not use the included screws, but used nuts and bolts instead. Pros: Works great for keeping the aux battery charged! Apart from the terminal lugs VERY easy to install. Cons: The relay is loud, event with the Ranger running you can hear it switch, a solid state relay would have been much better! The terminal lugs are not closed on the ring end.
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Reviewed in the United States on December 2, 2017 by chrissouth
Size: 140 AMP Kit
My GMC Sierra, or GM's in general, are apparently known for having power, or lack there of, issues and so when I added an electric fisher plow, my lights would dim and occasionally my radio would clear out, so I installed this unit. I don't yet know how it'll work with the plow but can say my voltage gage now runs steady so I'm hoping this solves my issue. I will say it was an easy install.
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Reviewed in the United States on October 21, 2024 by Don
Size: 140 AMP Kit
Why did you pick this product vs others?: Easy to install for my boat. I wanted something to isolate my starting battery from my battery that mainly runs my radio, so we can start the boat after floating and listening to the radio. I originally had an A/B/Both manual switch, that was hard to access. Now I can have enough left in one battery to get it started and not worry about flipping a switch or remembering to parallel them to charge them back up. The only thing about the install I didn’t like was having to trim out the side of the switch for the cables to route through. My boat alternator is rated for 65 amps, so this should handle that load without a problem.
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Reviewed in the United States on June 20, 2025 by Mike H.