Dual Battery Isolator Kit 12V - 140 Amp Voltage Sensitive Relay (VSR) for Dual Battery Setup
Condition: New
Buy Now, Pay Later
As low as
$19.16
/ mo
Learn more
- – 6-month term
- – No impact on credit
- – Instant approval decision
- – Secure and straightforward checkout
Ready to go? Add this product to your cart and select a plan during checkout.
Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Apple Pay, and PayTomorrow. No-credit-needed leasing options through Acima may also be available at checkout.
Learn more about financing & leasing here.
Selected Option
Free shipping on this product
30-day returns
Learn more
FREE 30-day refund/replacement
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
Availability:
In Stock.
Arrives
Monday, Feb 16
Recently Viewed
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.
Is Discontinued By Manufacturer : No
Product Dimensions : 2 x 2.6 x 2.6 inches; 8 ounces
Item model number : Iso-Pro140DBK
Date First Available : April 28, 2015
Manufacturer : KeyLine Chargers
Best Sellers Rank: #11,540 in Automotive (See Top 100 in Automotive) #3 in Automotive Replacement Battery Relocation Kits #81 in Automotive Replacement Battery Switches
#3 in Automotive Replacement Battery Relocation Kits:
#81 in Automotive Replacement Battery Switches:
Customer Reviews: 4.5 4.5 out of 5 stars (1,695)
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Monday, Feb 16
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.
- Klarna Financing
- Affirm Pay in 4
- Affirm Financing
- Afterpay Financing
- PayTomorrow Financing
- Financing through Apple Pay
Learn more about financing & leasing here.
Similar Products
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
...
show more
Reviewed in the United States on April 6, 2025 by tcg tcg
Size: 140 Iso-Pro
Worked perfectly.
Reviewed in the United States on September 28, 2025 by Janice
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.
...
show more
Reviewed in the United States on June 20, 2025 by Mike H.
Size: 300 AMP Isolator
This works well but the connections are very close together kinda made it difficult to install 4ga wire
Reviewed in the United States on November 8, 2025 by tee
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
...
show more
Reviewed in the United States on January 24, 2020 by KirbytheDiver KirbytheDiver
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
Size: 12/24 Volt 140 AMP Kit
Worked as advertised
Reviewed in the United States on September 27, 2025 by Joel D.
Size: 140 AMP Kit
Follow the installation instructions and your all set.
Reviewed in the United States on October 31, 2025 by David