To see product details, add this item to your cart. You can always remove it later.
FREE Returns
Added to

Sorry, there was a problem.

There was an error retrieving your Wish Lists. Please try again.

Sorry, there was a problem.

List unavailable.

12V Dual Battery 140A Smart Isolator (VSR Voltage Sensitive Relay) for Auto/Boat/RV

4.6 4.6 out of 5 stars 236 ratings

To see product details, add this item to your cart. You can always remove it later.
FREE Returns

Purchase options and add-ons

Contact Type Normally Open
Current Rating 140 Amps
Brand JayCorp
Operation Mode Automatic
Coil Voltage 12 Volts

About this item

  • 12V 140A smart isolator with Cut-In:13.4V, Cut-Out:12.9V
  • Easy connection at the battery. No need to bypass existing alternator wiring.
  • The smart isolator has no voltage drop. Conventional diode isolators incur a minimum of 0.6 volt drop
  • Compact 2.68" (68mm) by 2.68" (68mm) by 1.93" (49mm) size
  • Easy to install anywhere - Water and dust resistant - Mounting screws and detailed instructions included.
See more product details

Frequently bought together

$85.00
Get it as soon as Monday, Apr 1
Only 15 left in stock - order soon.
Sold by JayCorp Automotive and ships from Amazon Fulfillment.
+
$26.69
Get it as soon as Monday, Apr 1
In Stock
Sold by La Luna L and ships from Amazon Fulfillment.
+
$12.99
Get it as soon as Monday, Apr 1
In Stock
Sold by Ampper Direct and ships from Amazon Fulfillment.
Total price:
To see our price, add these items to your cart.
Details
Added to Cart
Some of these items ship sooner than the others.
Choose items to buy together.

Compare with similar items

This Item
12V Dual Battery 140A Smart Isolator (VSR Voltage Sensitive Relay) for Auto/Boat/RV
12V Dual Battery 140A Smart Isolator (VSR Voltage Sensitive Relay) for Auto/Boat/RV
Recommendations
GEARZAAR Dual Battery Isolator, 12V 140Amp Battery Isolator Voltage Sensitive Relay VSR Automatic Battery Smart Battery Isolator for Car Boat RV ATV UTV Marine
dummy
Newdeli 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charging Relay Dual Smart Battery Isolator
dummy
Mata1 Dual Battery Isolator Kit 12V 140Amp IP-67 Waterproof Rating VSR (Voltage Sensitive Relay) Smart Car Charger for All Automotive Land or Marine Vehicles
dummy
Spartan Power Smart Dual Battery Isolator 12V 140A Voltage Sensitive Relay VSR for Vans, Trucks, RVs, Motorhomes, ATV, UTV, Boats, Off Road Vehicles
dummy
Stinger SGP38 80-AMP Battery Isolator and Relay,BLACK
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Details
Added to Cart
Price$85.00$23.99$25.99$51.99$24.99$22.05
Delivery
Get it as soon as Monday, Apr 1
Get it as soon as Monday, Apr 1
Get it as soon as Monday, Apr 1
Get it as soon as Monday, Apr 1
Get it as soon as Monday, Apr 1
Get it as soon as Monday, Apr 1
Customer Ratings
Value for money
4.4
4.5
5.0
4.4
4.3
Easy to install
4.8
4.0
4.7
4.7
Instruction quality
5.0
4.0
4.4
Sold By
JayCorp Automotive
SiShuo-US
Yuxuan Online Store
Mendota Merchants
Inverters-R-US
Amazon.com
coil voltage
12 volts
12 volts
12 volts
operation mode
Automatic
Automatic
Automatic
Off

Product Description

A smart isolator is the ultra-simple and most technologically advanced method of automatic battery isolation. These units can be installed between batteries with a common ground to automatically control the charging process to the batteries but continue to provide isolation when a charging source is unavailable. The small size and rugged construction of these units allow for quick simple installation for even the most novice DIYer. The smart isolator is also “Dual Sensing” which senses the charge of both batteries. If either battery is receiving a charge, e.g. a battery charger is connected to the auxiliary battery; the relay will engage and charge both batteries. The advanced technology always insures that the first battery is fully charged (13.4v) before connection is made to the second battery. This prevents problems that may result from your charging source being too low in amps to charge all batteries as once. If placed in linear sequence between each battery the isolator units can provide proper charging for several batteries in a multiple battery setup such as in larger boats that may have 2 or more house batteries. How it works: The smart isolator allows two batteries to be charged at the same time. When the engine is started and either battery reaches 13.4 volts, the relay engages, allowing two battery banks (start and accessory) to be charged simultaneously. When the voltage drops below 12.9 volts (eg the engine is stopped), the relay disengages, separating the batteries. This system eliminates the possibility of draining the start battery and protects sensitive electronic equipment powered from the house battery from harmful engine start up spikes.

Product information

Technical Details

Additional Information

Warranty & Support

Amazon.com Return Policy:Amazon.com Voluntary 30-Day Return Guarantee: You can return many items you have purchased within 30 days following delivery of the item to you. Our Voluntary 30-Day Return Guarantee does not affect your legal right of withdrawal in any way. You can find out more about the exceptions and conditions here.
Product Warranty: For warranty information about this product, please click here

Feedback

12V

12V Dual Battery 140A Smart Isolator (VSR Voltage Sensitive Relay) for Auto/Boat/RV


Found a lower price? Let us know. Although we can't match every price reported, we'll use your feedback to ensure that our prices remain competitive.

Where did you see a lower price?

/
/
/
/
Please sign in to provide feedback.

Looking for specific info?

Customer reviews

4.6 out of 5 stars
4.6 out of 5
236 global ratings

Customers say

Customers like the performance, ease of installation, battery life, and quality of the relay. For example, they mention it works well, is easy to follow directions, and keeps both batteries charged. That said, opinions are mixed on value.

AI-generated from the text of customer reviews

60 customers mention57 positive3 negative

Customers are satisfied with the performance of the relay. They mention that it works well, has no issues, and is perfect for battery isolation. Some say that the battery sensor works great as well. Overall, most are happy with their purchase and recommend it to others.

"...told by many old school camper guys this setup wouldn't work, but it works great! The VSR is small and lightweight, and simple to hookup and use...." Read more

"Worked great while it lasted ... about two months into operation I serviced my truck myself during which I disconnected the negative battery pole..." Read more

"...I have tested it with my volt meter and thus far it has worked perfectly...." Read more

"...on if it would work with the type of alternator I have but it worked great...." Read more

29 customers mention29 positive0 negative

Customers find the installation of the relay to be simple, easy to follow directions, and easy to connect.

"...The VSR is small and lightweight, and simple to hookup and use. It has one simple LED light letting you know where it's sending voltage...." Read more

"...than a conventional battery isolator but it is smaller and easier to connect...." Read more

"...Im an idiot with electricity but the instructions are straight forward." Read more

"It was easy to install and it has been working like it's supposed to so far have it installed on sxs so we see if it stays good?..." Read more

17 customers mention17 positive0 negative

Customers are satisfied with the quality of the battery isolator. They mention it's reliable, simple, and well-made. Some say that it'll be a great addition to your vehicle's battery system.

"...Either relay looks to be a great solution for battery isolation." Read more

"great isolator for second battery, really works- no bleed back after 6,000 milesWould get a 5**** if it had mounting lugs...." Read more

"...draining the auxiliary batterie on a horse trailer, the smart battery isolator was perfect for splitting those two circuits when not charging and..." Read more

"...The unit installed easily and is functioning as designed. Very well made." Read more

15 customers mention12 positive3 negative

Customers like the battery life of the relay. They mention that it works as advertised, keeps both batteries charged, and provides power for a couple of days. It also prevents power surges, which can destroy your engine.

"...Truck battery stayed full too. Im an idiot with electricity but the instructions are straight forward." Read more

"...But it works as advertised and does keep the batteries properly charged...." Read more

"...This unit will also prevent power surges which can destroy your Engine Management Computer, this can happen when you use a plain relay to isolate..." Read more

"...for a long time because the 2nd battery was ruined and would no longer take a charge. I emailed the manufacturer (TRUE) to ask for help...." Read more

8 customers mention5 positive3 negative

Customers are mixed about the value of the relay. Some mention it's very good for the money, while others say it'd be better spent helping others.

"...Li-Ion jump starter packs are super cheap and more useful for helping others anyway." Read more

"...It is a little more expensive than a conventional battery isolator but it is smaller and easier to connect...." Read more

"Good value and works well for the past month" Read more

"Very good for the money..." Read more

7 customers mention4 positive3 negative

Customers are mixed about the size of the relay. Some mention that the small size and plastic enclosure make fitting it in the little, while others say that the lugs and studs are too small on the back.

"...The VSR is small and lightweight, and simple to hookup and use. It has one simple LED light letting you know where it's sending voltage...." Read more

"The studs are too small on the back and they are too close to the openings. Makes it really tricky to put 6 ga. battery lugs on." Read more

"...As much as I like this device, it's functionality, size, and even the design..." Read more

"...would typically install to battery post in a boat and it comes with a lug that is too small. Maybe a little longer as well...." Read more

Installed and it is working as planned!
4 Stars
Installed and it is working as planned!
Thank you for your feedback
Sorry, there was an error
Sorry we couldn't load the review

Top reviews from the United States

Reviewed in the United States on January 21, 2012
59 people found this helpful
Report
Reviewed in the United States on November 6, 2016
98 people found this helpful
Report
Reviewed in the United States on August 26, 2011
31 people found this helpful
Report
Reviewed in the United States on May 21, 2022
5 people found this helpful
Report
Reviewed in the United States on April 7, 2021
One person found this helpful
Report
Reviewed in the United States on September 4, 2019
7 people found this helpful
Report
Reviewed in the United States on August 15, 2023