The Best 12V Isolator of 2025 – Reviewed and Top Rated
After hours researching and comparing all models on the market, we find out the Best 12V Isolator of 2025. Check our ranking below.
2,254 Reviews Scanned
Rank No. #1
12V 140 Amp Dual Battery Isolator Kit - Voltage Sensitive Relay (VSR) Double Battery Automatic Charger, Fits Car, Vehicle, RV, ATV, UTV, Boat, Camper, Truck
- AutoDunk dual battery isolator kit. Ensures your main battery is always charged and ready to start your vehicle. The voltage sensitive relay (VSR) cuts in at 13.3 volts and cuts out at 12.8 volts. It's like having two separate power sources for each battery and only one alternator.
- This compact battery isolator was built ultra-small to fit almost anywhere! A perfect fit under the hood to get close to your dual batteries. Suitable for almost anywhere even off-road, which is water resistant, shock resistant, dust proof and withstand unexpected extreme weather environments.
- Used for DC 12 V two battery systems isolate and charge, universal used for car, vehicle, RV, ATV, UTV and boat, also two battery electrical equipment.
- AutoDunk isolator is safe for use even for your off-road needs in dusty, wet and unexpected extreme weather environments. Great for extreme vibration applications as well.
- Package Includes: 1x battery isolator; 1x red battery cable; 1x black ground battery cable; 2x positive battery terminal; 1x negative battery terminal; 3x crimp lug; 2x heat shrink; 1x ring terminal; 6x cable tie; 4x screw.
SaleRank No. #2
Stinger SGP32 200 AMP Battery Relay Isolator and Relay
- 200 AMP Battery Isolator and Relay
- Prevents primary battery discharge
- Maximum current transfer
- Extends battery life
- Universal 12V Applications
Rank No. #3
Battery Isolator 12v 140Amp Battery Isolator Relay VSR RVS Yachts Double Battery Automatic Charging Relay Dual ZJWAQH
- 【Features】：12V, 140A, 13.3V cut-in voltage, 12.8V cut-out voltage.
- 【Function】：Like Having Two Separate Power Sources, The Dual Battery Isolator Kit Enables Your Accessories to Run From a Separate Battery While the engine is not running on your vehicle While keeping your Main Battery Charged and Your Vehicle Always Ready to Go and Start When You Want It.
- 【Compatibility】：used for DC 12 V two battery systems isolate and charge, universally used for car, vehicle, RV, ATV, UTV, and boat, also two battery electrical equipment.
- 【Easy to use】： Having Voltage Sensitive Chip, Rely Cuts in at 13.3 Volts and Cuts out at 12.8 Volts to Ensure Primary Battery is Always Ready for Vehicle to Run.
- 【Warranty】：constructed with a weatherproof body（IP65）and durable silver-tipped contacts.100% High Quality and Enjoy Full Life Warranty, Free Exchange
Rank No. #4
MaySpare 200 Amp Mobile Audio Continuous Relay and Battery Isolator High Current Relay 12VDC
- Function: An isolator is used to combine two batteries when a alternator is charging ( engine running) and isolate them when not charging ( engine off) so you can still start your vehicle
- Voltage: 12VDC/ Dimensions: 2-3/8"W x 2-3/8"D x 3-3/4"H/Power Handling: Continuous power handling of 200 amps/ Surge Power Handling: 300 amps
- Advantage: Does not create a voltage drop to the second battery like conventional isolators
- Wrie Diagram : Connect the two small studs one to ground the other to an ignition on source from fuse box , the order on the large/ small studs does not matter
- Provide better service, please contact us if you have any questions!
SaleRank No. #5
Spartan Power Smart Dual Battery Isolator 12V 140A Voltage Sensitive Relay VSR for Vans, Trucks, RVs, Motorhomes, ATV, UTV, Boats, Off Road Vehicles
- Stay Prepared: The Spartan Power Dual Battery Isolator is a smart battery isolator that helps you stay prepared for any situation; It allows you to run two batteries simultaneously, protecting and maintaining the two-battery system while optimizing the charge
- Versatile: Our VSR Battery Isolator can be used to protect any 12 Volt battery; It eliminates the possibility of running the battery out and keeps it fully charged for when you need it most
- Simple to Use: This Dual Battery Isolator is easy to install and operate; Simply connect the two batteries to the isolator and it will efficiently transfer the charge from one battery to another, saving you time and trouble
- Safe: With the Dual Battery Isolator, you never have to worry about overcharging or shorting out your car’s electrical system; It is designed to be safe and reliable, keeping your car running smoothly
- Giving Power to The People: Helping people arm themselves with the right tools and accessories, Spartan Power manufactures ultra-high quality, Made in the USA battery cables every day in Reno, Nevada; Trusted by professionals, enthusiasts, and DIYers everywhere
SaleRank No. #6
Dual Battery Isolator 12V 140 Amp with Voltage Display Auto & Manual Mode Voltage Sensitive Relay (VSR) Auto Charger Truck Smart Battery Isolator for ATV UTV Truck Marine RV
- 【Manual State Function】： Long Press the button for 3 seconds, the BLUE led will be On, and the manual mode is on. Press the button each time, you can complete the circuit connection and disconnection. Circuit switched on the red indicator, voltmeter lights up at the same time. Switched off the red indicator, voltmeter lights off.
- 【Auto State Function】： Long press the button for 3 button again, the BLUE led will be Off, the Auto mode is on. Voltage exceed 13.3V: Circuit will be automatically connected. Voltmeter & Indicator ON. Voltmeter lower than 12.7V: Circuit will be automatically disconnected. Voltmeter & Indicator Off.
- 【Voltage Display】： This dual battery isolator is constructed with a voltmeter which will display the real-time voltage. If you connect 2 batteries, then the voltmeter will display the battery that has high voltage. The smart battery isolator is universal fit for truck, UTV/ATV, boat, marine, bus, etc.
- 【Voltage Sensitive Relay】： Cut-in voltage: 13.3V and Cut-out voltage: 12.8V. Ensure the main battery is always charged so that you won’t worry about the the battery will drain out and stuck on the road. Very convenient and safe to use.
- 【Pressure Protection】： Input voltage lower than 11V or Input voltage more than 17V: Circuit will be automatically disconnected so as to protect the main battery from over discharging. Please buy and use the dual battery isolator with confident, and don't hesitate to tell us if you have any questions for the battery isolator.
Rank No. #7
Jtron Car Battery Switch Disconnect 12v 200A Cut Off RV Battery Isolator Switch with 2 Keys for RV Ship Boat Small Yacht Camper Truck
- Heavy Duty: ABS plastic Battery Disconnect Isolator Master Switch with 2 Removable Key Rust and corrosion resistant, Solid cooper nuts and brass washers.
- Operation: 2 brass Copper pillar: 0.33"/8mm; Used for DC 12-24 V systems, On/Off 2 position, rated current: 100A (12V ), Max; Withstanding current: 200A (12V ).
- Easy operation: Disconnect and reconnect battery by one simple turn of the knob on it; The key Can Be Taken Down When There is No Power Connection; In this way,Power Supply Will Not Be Viciously Switched On; Waterproof Case Can Better Protect Key Hole.
- Purpose: Disconnects the battery safely,to eliminate any power draw from the battery when vehicle or boat is not in use,sleek modern appearance,sturdy and durable,Widely Used For Car,Marine,Boat,RV,Camper,Truck,ATV, UTV,Battery Banks And Other 12-24V Devices.
- Contact our customer service for assistance with troubleshooting, parts, or replacement; We are committed to providing high-quality parts and excellent service.
Rank No. #8
Dual Battery Isolator Kit 12V - 140 Amp Voltage Sensitive Relay (VSR) for Dual Battery Setup
- 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”, it’s 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 levels—just connect the power wire in, power wire out, and you’re 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 you’re not 100% satisfied with your purchase, take advantage of our 30-day money-back guarantee—no questions asked! Drive with confidence knowing you have a premium battery isolator 12V kit keeping your power system running at full capacity.
SaleRank No. #9
Dual Battery Smart Isolator DEWINNER - VSR - Voltage Sensitive Relay, 12V 140 Amp Specially Designed for ATV, UTV, Boats, RVs, Campers 5th Wheels Off Road Vehicles Rhino (12V Isolator)
- Easy to Install: No alternator or ignition connection needed. If you want additional components to complete installation, please click "DEWINNER dual battery isolator kit".
- VOLTAGE SENSITIVE RELAY: DEWINNER Automatic 140 Amp Dual Battery Isolator is all you need to charge Two Battery Systems. Voltage Sensitive Relay (VSR) cuts in at 13.3 volts and cuts out at 12.8 volts to ensure your primary battery is always charged and ready to start your vehicle. It's like having two separate power sources for each battery while only having one alternator! (Only suitable for lead-acid batteries versus lead-acid batteries)
- FITS A WIDE VARIETY OF VEHICLES -Like Having Two Separate Power Sources,The Dual Battery Isolator Kit Enables Your Accessories to Run From a Separate Battery While the engine is not running on your vehicle While keeping your Main Battery Charged and Your Vehicle Always Ready to Go and Start When You Want It. Suitable for 12V 4WD, marine, truck, caravan & camping applications
- WHAT YOU GET: SingleIsolator: 140 Amp Smart Battery Isolator; Easy-to-follow directions for the novice DIYer.
- BUY WITH CONFIDENCE: Every 140 Amp Dual Battery Isolator is backed by an industry leading 12-month warranty. If you are not 100% satisfied with your purchase, simply take advantage of the No Questions Asked, 30-Day Money Back Guarantee!!
Rank No. #10
12V 140Amp Dual Battery Isolator, Ampper Battery Voltage Sensitive Relay (VSR) Smart Battery Isolator for Car, Vehicle, RV, ATV, UTV and Boat
- Purpose: this voltage sensitive relay is design for two battery systems (SUITABLE for Acid-Lead batteries, NOT SUITABLE for Lithium batteries), allow to having two separate power sources while charging by one alternator, it's all need to charge and isolate two battery systems.
- Primary Battery Protected: cuts in at 13.3 volts and cuts out at 12.8 volts. Ensure your primary battery is always charged and ready to start your engine, the secondary will be charged after the primary battery's volts exceed 13.3 volts.
- Heavy Duty: this voltage sensitive relay is heavy built to suitable for almost anywhere even off-road, which is water resistant, shock resistant, dust proof and withstand unexpected extreme weather environments.
- Compatible: used for DC 12 V two battery systems isolate and charge, universal used for car, vehicle, RV, ATV, UTV and boat, also two battery electrical equipment.
- Easy to use: this VSR comes with mounting plate and 4 bolts for install.
Last update on 2022-12-30 / Affiliate links / Images from Amazon Product Advertising API
How Do You Buy The Best 12V Isolator?
Do you get stressed out thinking about shopping for a great 12V Isolator? Do doubts keep creeping into your mind? We understand, because we’ve already gone through the whole process of researching 12V Isolator, which is why we have assembled a comprehensive list of the greatest 12V Isolator available in the current market. We’ve also come up with a list of questions that you probably have yourself.
We’ve done the best we can with our thoughts and recommendations, but it’s still crucial that you do thorough research on your own for 12V Isolator that you consider buying. Your questions might include the following:
- Is it worth buying an 12V Isolator?
- What benefits are there with buying an 12V Isolator?
- What factors deserve consideration when shopping for an effective 12V Isolator?
- Why is it crucial to invest in any 12V Isolator, much less the best one?
- Which 12V Isolator are good in the current market?
- Where can you find information like this about 12V Isolator?
We’re convinced that you likely have far more questions than just these regarding 12V Isolator, and the only real way to satisfy your need for knowledge is to get information from as many reputable online sources as you possibly can.
Potential sources can include buying guides for 12V Isolator, rating websites, word-of-mouth testimonials, online forums, and product reviews. Thorough and mindful research is crucial to making sure you get your hands on the best-possible 12V Isolator. Make sure that you are only using trustworthy and credible websites and sources.
We provide an 12V Isolator buying guide, and the information is totally objective and authentic. We employ both AI and big data in proofreading the collected information. How did we create this buying guide? We did it using a custom-created selection of algorithms that lets us manifest a top-10 list of the best available 12V Isolator currently available on the market.
This technology we use to assemble our list depends on a variety of factors, including but not limited to the following:
- Brand Value: Every brand of 12V Isolator has a value all its own. Most brands offer some sort of unique selling proposition that’s supposed to bring something different to the table than their competitors.
- Features: What bells and whistles matter for an 12V Isolator?
- Specifications: How powerful they are can be measured.
- Product Value: This simply is how much bang for the buck you get from your 12V Isolator.
- Customer Ratings: Number ratings grade 12V Isolator objectively.
- Customer Reviews: Closely related to ratings, these paragraphs give you first-hand and detailed information from real-world users about their 12V Isolator.
- Product Quality: You don’t always get what you pay for with an 12V Isolator, sometimes less, and sometimes more.
- Product Reliability: How sturdy and durable an 12V Isolator is should be an indication of how long it will work out for you.
We always remember that maintaining 12V Isolator information to stay current is a top priority, which is why we are constantly updating our websites. Learn more about us using online sources.
If you think that anything we present here regarding 12V Isolator is irrelevant, incorrect, misleading, or erroneous, then please let us know promptly! We’re here for you all the time. Contact us here. Or You can read more about us to see our vision.