Dual Battery Isolator Kit 12V - 140 Amp Voltage Sensitive Relay (VSR) for Dual Battery Setup
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Availability:
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Thursday, Oct 1
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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.
Description
An US Battery Isolator Supplier - Often Imitated, Never Duplicated. Trust the Experts at Keyline Chargers who Know this Business Best. KeyLine Chargers is a privately held company located in Detroit, MI. We are proud to be delivering Battery isolators and accessories within the Recreational Vehicle industry. We have been working hard to develop new products that meet the needs of your rugged, extreme…and sometimes unexpected lifestyle.
Product Dimensions: 2 x 2.6 x 2.6 inches
Item Weight: 8 ounces
Manufacturer: KeyLine Chargers
Item model number: Iso-Pro140DBK
Date First Available: April 28, 2015
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Thursday, Oct 1
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
Installed in a 98K1500. Does the job perfectly
Reviewed in the United States on June 14, 2026 by David
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
Easy to install
Reviewed in the United States on April 17, 2026 by Amazon Customer
Size: 140 AMP Kit
Plenty of wire although the ground wire could be longer. The positive is only 7 gauge wire and should be thicker but they give you 20 feet of it. The product works as it should and installing it was easy. The isolator cover has 4 knockouts in the cover to alow wire to go through the sides however none of them line up so you have to make your own holes. There is no manual control wire to close the circuit for jumping one battery off the other like some other brands. I ended up removing the isolator and installing a DC-DC charger from REDARC because I have a smart alternator system and this system won't fully charge my AGM auxiliary battery to full. If you have a shunt on you negative start battery post or somewhere on your negative cable then you have a smart alternator and this product will not work for you to it's full potential. It's fine for older vehicles. A smart alternator charges your start battery to full then drops off to 12.6 to 12.8 volts until the battery requires more charge. I suppose this is for full economy. When this happens no extra charge is available to your auxiliary battery and in the case of an AGM battery the voltage of 14.6 that is required is never reached. Some lithium batteries require 15 volts or more to fully charge. A DC-DC charger is customized to your auxiliary battery's needs. It monitors and charges it fully and indepently of your start battery regardless of the alternator output. I found this out the hard way so don't make my mistake by buying a simple isolator kit and realizing it won't do what you want it to. This is old technology for older cars.
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Reviewed in the United States on June 29, 2021 by waggs
Size: 140 AMP Kit
Works great on my 2025 can am defender dual battery set up.
Reviewed in the United States on May 24, 2026 by Amazon Customer
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.
Size: 140 AMP Kit
I love how these work.
Reviewed in the United States on June 19, 2026 by William Givens