/ / / Top 5 Best Dual Battery Isolators and Kits [Buying Guide]

Top 5 Best Dual Battery Isolators and Kits [Buying Guide]

Product NameImageProsPrice
KeyLine Chargers Dual Battery IsolatorEasy installation.
Compact, simple design.
Sturdy construction.
Comes with a one-year warranty.
Check Price on Amazon
True UTV-SBI-CK UTV Dual Battery KitComes with silicone insulators.
Features 3M dual lock fastener.
Has a 36mm blue led voltmeter along with a dual display.
Automatic isolator battery.
Easy to follow instructions.
Check Price on Amazon
JOYHO 140Amp Smart IsolatorRugged durability.
Easy installation.
Withstands weather environment.
It's water-resistant.
Check Price on Amazon

Installing a dual battery in your van maybe one of the best ideas you may want to look out for. Regarding the benefits that come with it; from powering portable refrigerators, installing additional lighting and sockets to power up your mobile charger, the benefits cannot be less.

Upon installing additional appliances that consume power, a normal battery will drain the power so fast especially if the vehicle is not moving to leave you stranded in the middle of nowhere when it fails to start up. However, with the introduction of a dual battery, such problems are solved.

Best Battery Isolators Reviewed

KeyLine Chargers Dual Battery Isolator

It is hard to be well acquainted with an impressive yet captivating battery isolator. But this one has earned hearts. This model maintains an amperage output in an awe-inspiring way, which is impossible with other devices.

The VSR holds a charged battery for a longer duration. It features a dual battery isolator that is140 Amp. And it is enough for setting a dual battery system. Moreover, it offers the ability to separate each battery’s power source using this single alternator.

It features a 2-foot battery grounding cable and 20-foot battery cable, which is in black and later one in red color.

What makes it the best dual battery isolator & kit is its stunning design and build. It has a compact size of around 2.6 x 2.6 x 2-inches to fit in different places easily.

The Isolator is also IP65 certified, which makes it ideal for off-road purposes. But that doesn’t mean it’s authorized for submersion within the water. It’s only immune to light spraying and protection against rain.

Its sturdy construction and pairing with thick, well-protected cables. This makes it ideal to encounter vibration. Plus, the setup of this isolator is quite simple.


  • Easy installation.
  • Compact, simple design.
  • Sturdy construction.
  • Comes with a one-year warranty.
  • Fits well to a wide range of trucks along with off-road vehicles.
  • Zero voltage drop.
  • Rugged durability.
  • It is voltage-sensitive.
  • Smart charging.
  • Water/ dust/ vibration resistant.


  • Vague instructions for newbies.

Check Price on Amazon

True UTV-SBI-CK UTV Dual Battery Kit

If you plan to invest in a dual battery kit that works well in humid or rainy areas, this is a superlative choice. The sealed cables with an adhesive coating prevent corrosion. It is a perfect solution for people who reside in subtropics.

This model comprises a true UTV-SBI-18 smart battery isolator built using ground up to maintain stator charging mechanism.

This kit offers stunning charge management for the accessory battery. It also protects the primary battery during startup.

True kits also feature the industry’s well-known fully adhesive sealed and 100% waterproof and dustproof cables. Plus, this kit comes with three different mounting forms.

Those include traditional screw type, leaving it suspended within wires, or 3M dual lock fastener. The top-notch quality and performance of this dual battery isolator and kit are unmatchable.

Last but not least… It comes with true 18” and 12” sealed 6ga red and black cables and 6mm lugs.


  • Comes with silicone insulators.
  • Features 3M dual lock fastener.
  • Has a 36mm blue led voltmeter along with a dual display.
  • Automatic isolator battery.
  • Easy to follow instructions.


  • Cables could be a little longer

Check Price on Amazon

JOYHO 140Amp Smart Isolator

It is a top-notch quality system with rugged durability. This is an ideal battery isolator for charging a dual battery system. It comes with a sensitive chip that ensures the primary battery is ready to operate.

Moreover, this isolator is built to undergo all-weather environments and withstand vibration. Its water-resistance is another quality.

There’s no need for any ignition connection or alternator, so you don’t need extra installation components. Everything comes in this kit, including connectors, leads, zip ties, screws, and much more.

It is a sensitive relay as it’s a 140 Amp dual battery isolator you need for charging two battery systems.

The VSR cuts in ranging 13.3 volts while it cuts out for 12.8 volts ensuring the primary battery is charged for starting the vehicle. This indicates that this dual battery isolator comes with multiple powers for a single battery.

Buy now with ultimate confidence as it fits well for a wide range of vehicles. It works well with 12V 4WD, trucks, caravan, marine, and several camping applications.


  • Rugged durability.
  • Easy installation.
  • Withstands weather environment.
  • It’s water-resistant.
  • Suitable for several vehicles.


  • No clear instructions about the hooking unit to ignition.

Check Price on Amazon

AOPEC Dual Battery Isolator Kit

If you are concerned about your safety, this AOPEC dual battery isolator will be the number one choice. It features a protective design which sustains protection over current or voltage problem. Plus, it comes with efficient charging, which allows the isolator to distribute charging between dual batteries effectively.

AOPEC battery maintains a connection with both batteries at the time of charging while disconnects during isolation.

It comes with primary battery priority charging. This prevents the discharge of the battery and lengthens its life at the time of shutoff of your vehicle’s engine. This certainly reduces the chances of suffering from a flat starter battery.

You’ll feel awe with the silicon-sealed internal layer and external plastic housing. It protects the isolator from dust, dirt, damage, and sand, making it weatherproof.

Moreover, this company offers a 24-months warranty to the users with top-notch quality physical components and stunning design. It also allows the isolator to provide stable performance to the buyers.

Besides that, its unit indicator LED stays on when the dual batteries are charging simultaneously.


  • Weatherproof.
  • Wiring Diagram.
  • Easy to Install.
  • Unit indicator LED.
  • Includes cables.


  • Wire quality not that good.

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True UTV-SBI-CM UTV Dual Battery Kit

You’ll get good charge management of your accessory battery and this kit will protect your primary battery for starting.

This True UTV battery isolator kit features a single meter and dual display. But measures 1” in thread depth, which means it needs slightly more room other than the surface. But other than that, it can be easily mounted with a thicker material.

Like the original meters, it has 36mm shockproof/ waterproof digital LED voltmeters. These allow the buyers to maintain real-time track of all the happenings regarding a single battery’s charge status.

This battery isolator kit comes with all the essential items for easy installation, including the meters properly turn on or off with the ignition. You can easily mount the meter anywhere having a flat surface.
Apart from that,  you can use any of the 3 types of mounting, 3M Dual Lock fastener, traditional screws, or suspended cables.


  • Comes with a silicone insulator.
  • It features a 3M dual lock fastener.
  • LED voltmeters having a dual display.
  • Easy installation.
  • 100% waterproof.
  • Great quality.


  • You need connectors for ground and power wires.

Check Price on Amazon

What Are Dual Battery Isolators And How Do They Function?

As the name suggests, isolators function by isolating the primary battery which is used to start the vehicle leaving it to maintain its charge when the engine is not running. If your RV has additional appliances such as portable refrigerators or additional lighting bulbs, which uses the vehicle’s battery power, the moment the engine stops running, the isolator will cut off the primary battery used to start the engine so that the appliances don’t drain both batteries.

When a vehicle’s engine is started, there is a surge of power to the starter which triggers the alternator making it start producing power. The isolator responds by providing power to the primary battery until it is charged fully. Upon the primary battering reaching its maximum, the current is switched to the auxiliary battery. The current that is used to power up the appliances is derived from the auxiliary battery.

Manual Vs Automatic Battery Isolators

Manual switches can also be used in isolating the batteries. Both will serve the same purpose of providing current to the primary battery until it is fully charged then switches the current to charge the auxiliary battery which powers the appliances in your RV.

A manual switch requires human intervention. This poses a challenge since humans forget easily and in an instance where the isolator is not turned on draining all power in the primary battery, the vehicle will stall. Automatic isolators will links the batteries for charging and isolate them while discharging, very smart, right? An isolator with surge protection is recommendable as it protects the vehicles onboard computer.

Top Batteries for The Dual-Battery System

Batteries come in two main forms, either shallow cycle (single high-current discharge) or deep-cycle battery. Shallow cycle batteries are mainly found in vehicles from the manufacturer.  They provide a high amp charge which is able to start the engine.

Deep-cycle batteries provide sustained power over long periods of time hence preferred as an auxiliary battery for a dual battery system. The deep-cycle battery is larger in size and more expensive as compared to their counterpart shallow-cycle battery.

The dual-battery system varies in size and weight. Variation in the internal lead plates in terms of numbers ad thickness brings out the overall difference. The internal lead plate and their thickness define the amp-hour capacity of the battery. For a better dual-battery, choose one with more lead plates and whose terminals are dual fit.

Shallow-cycle batteries have thinner plates and take less time to charge to full as compared to deep-cycle batteries which have thicker plates and takes more time to charge to full. In a dual-battery system, it is necessary to put into consideration if the battery isolator is capable of charging both batteries.

While on a mission to purchase a dual-battery system, it is necessary to put into consideration the type and formation of the batteries.

Which Are the Best Types Of Isolators

There exist numerous isolators in the market but this article shortlists the best and highly regarded.

Diode Isolators

The battery circuits in this type are isolated from each other. Each battery is an independent power source since the current flow is isolated. The circuits act as a one-way valve between batteries.

Solenoid Isolators

This type charges the batteries in a parallel manner. When the ignition of the van is turned on, the solenoid isolator switches on allowing the current to flow in both batteries. When the primary battery is full, the isolator solely diverts all the current to the auxiliary battery. For parallel charging dual-battery, it is recommended the batteries be uniform; of the same age, capacity, size, and of the same design. When the ignition is turned off, the isolator’s switch automatically isolating the primary battery and the auxiliary battery is left for consumption.

Electronic Isolators

In the dual battery system, electronic isolators are regarded as the best. The batteries are not a must be identical and of the same properties, the electronic isolators are modified I manner to recognize and identify the difference in the batteries adjusting the charge rate. However, the primary battery is obviously given priority allowing it to charge while the engine is running and isolating it when the engine is off.

On the basis of vehicle usage, it is best to choose the right system. For RVs, the van will mostly be on-road hence the system should not be of concern on dust and water resistance features. For off-road vehicles, the best system is one with water and dust resistance features.

Smart Solenoids

This type of isolator is essentially a smarter version of solenoid isolators. They possess voltage sensors that allow automatic operation. They are smart enough to hold voltage to the auxiliary battery until the primary battery reaches a predetermined voltage then charging commences to the auxiliary battery. Charging proceeds parallel for the dual battery.

When the ignition is turned off, the smart solenoid sensor turns on. Draining of the primary battery will reach a predetermined voltage then the sensor will isolate it leaving the auxiliary battery to be used by the electrical appliances. The sensors function in such a manner to avoid draining all power and flattening of the starting battery.

Voltage Sensing Relays Isolators

They function like smart solenoid isolators. However, the charging of the dual battery is not parallel. In addition, it uses a relay and not a sensor with the two batteries electrically separated. In an instance when the main battery drains below a predetermined level, the auxiliary battery is disconnected from charging to charge the primary battery to its predetermined level.

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