How does a voltage sensitive relay work?

It connects the two batteries only when the charging voltage rises above a set threshold, then disconnects when the engine stops. That keeps accessories from draining the starting battery.

Can I use it with a winch?

The 80-amp rating suits lights, radios and moderate accessories. A heavy winch can draw far more, so check its draw before wiring it through this isolator.

Does it work on a boat or jet ski?

Yes, it is built for 12V systems and the sealed housing resists water and dust. Mount it where it stays dry and secure.

The isolator unit itself. Wiring, fuses and mounting hardware are not included, so plan for those separately.

Do I need a second battery?

Yes, the isolator manages two 12V batteries. It does not create extra capacity on its own.

Is it better than a DC-DC charger?

A DC-DC charger handles voltage differences and charges smarter, especially with lithium. This relay is simpler and suits basic lead-acid dual-battery setups.

Where is the VEVOR Dual Battery Isolator Kit, 12V 80 Amp cheapest?

At Walmart, for $33.83, as of our latest check.

Where can I buy the VEVOR Dual Battery Isolator Kit, 12V 80 Amp?

2 stores we checked sell it, including Walmart, Amazon.

VEVOR Dual Battery Isolator Kit, 12V 80 Amp

Best price now

$33.83at WalmartChecked Nov 12

Compared across 2 stores. Prices are checked against each store and labelled with when.

Visit Walmart

VEVOR Dual Battery Isolator Kit, 12V 80 Amp

Best price now

$33.83at WalmartChecked Nov 12

Compared across 2 stores. Prices are checked against each store and labelled with when.

Visit Walmart

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Price facts

Last seen at $33.83 at Walmart on Nov 12.
Checked at 2 stores.

Our take on the VEVOR Dual Battery Isolator Kit, 12V 80 Amp

The VEVOR Dual Battery Isolator Kit is a 12V, 80-amp voltage sensitive relay that keeps a main and an auxiliary battery isolated so one can't drain the other. It connects the two only when the charging system raises voltage, so the starting battery stays ready while accessories run off the second battery. A dual voltage display shows both batteries' live readings at once. Its compact, sealed plastic housing suits UTVs, ATVs, jet skis and snowmobiles, and it installs with basic tools. Against pricier name-brand isolators it offers the same core function with fewer frills; owners of small off-road and marine rigs tend to find it adequate, while some report the terminals and instructions are basic.

Best forUTV, ATV and side-by-side owners adding a second batteryJet ski and snowmobile electrical setupsCampers and overlanders running accessories off an auxiliary batteryDIY installers who want a simple relay-style isolator

Pros

80-amp 12V rating handles typical auxiliary loads
Keeps the starting battery from being drained by accessories
Dual display shows both battery voltages at once
Sealed plastic housing resists water, dust and shock
Compact size fits tight engine bays and powersports frames
Installs with basic tools and no special knowledge

Cons

Relay-style design is simpler than smart DC-DC chargers
Wiring and instructions are basic; no harness included
80 amps limits heavy winch or high-draw accessory use
No Bluetooth or app monitoring

VEVOR Dual Battery Isolator Kit, 12V 80 Amp prices at every store

WalmartNew
In stockSold by VEVOR Distribution StoreReturns: Sold by a Walmart Marketplace seller; returns go to the seller under the seller's returns policy.
$33.83Free shippingChecked Nov 12
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AmazonNew
Availability unknown
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$33.83Checked Nov 12
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VEVOR Dual Battery Isolator Kit, 12V 80 Amp price history

Lowest price we've seen: $33.83 on Nov 12 at Amazon. Tracked across 1 store since Nov 12.

What reviewers say

Owners of UTVs, ATVs and small boats generally find the isolator does its job, keeping the starting battery charged while accessories run on the second battery. Complaints center on sparse instructions and basic terminals rather than the isolation itself.

What people mention

Isolation functionPraisedOwners say it keeps the starting battery from draining when accessories run on the second battery.
Voltage displayPraisedThe dual readout for both batteries is called useful for monitoring charge.
BuildMixedThe sealed housing holds up off-road, but terminals and hardware feel basic.
InstructionsCriticisedBuyers say the wiring guidance is sparse and they had to work out the hookup themselves.
Amp ratingMixed80 amps covers normal accessory loads but is tight for winches and high-draw gear.

About the VEVOR Dual Battery Isolator Kit, 12V 80 Amp

This dual battery isolator kit connects a main battery and a backup battery in vehicles such as UTVs, ATVs, jet skis and snowmobiles. It uses dual-battery isolation to prevent cross-feeding and battery depletion, so the main battery stays charged and ready to start.

The casing is high-strength plastic. It is waterproof, dust-resistant and shockproof, and it resists impact. The unit shows the real-time voltage of both the main battery and the backup battery at the same time.

The body is compact and lightweight, so it fits into tight vehicle layouts. It can be mounted under the hood or in an off-road vehicle. Installation needs only basic tools and a few steps, and no professional knowledge.

Model: VSR004
Rated voltage: DC 12V
Rated current: 80A
Color: Black
Material: Plastic PA6 isolator, copper wire
Dimensions: 3.3 x 1.7 x 1.5 in (85 x 43 x 37 mm), L x W x H
Weight: 0.9 lbs (0.43 kg), including all accessories
Display: Dual voltage display for main and backup battery
Use with: UTVs, ATVs, jet skis, snowmobiles
In the box: 1 x Dual Battery Isolator Kit, 1 x User Manual

Specifications

color: BlackSource
size: 3.3" x 1.7" x 1.5"Source

Questions and answers

How does a voltage sensitive relay work?: It connects the two batteries only when the charging voltage rises above a set threshold, then disconnects when the engine stops. That keeps accessories from draining the starting battery.
Can I use it with a winch?: The 80-amp rating suits lights, radios and moderate accessories. A heavy winch can draw far more, so check its draw before wiring it through this isolator.
Does it work on a boat or jet ski?: Yes, it is built for 12V systems and the sealed housing resists water and dust. Mount it where it stays dry and secure.
What is in the box?: The isolator unit itself. Wiring, fuses and mounting hardware are not included, so plan for those separately.
Do I need a second battery?: Yes, the isolator manages two 12V batteries. It does not create extra capacity on its own.
Is it better than a DC-DC charger?: A DC-DC charger handles voltage differences and charges smarter, especially with lithium. This relay is simpler and suits basic lead-acid dual-battery setups.
Where is the VEVOR Dual Battery Isolator Kit, 12V 80 Amp cheapest?: At Walmart, for $33.83, as of our latest check.
Where can I buy the VEVOR Dual Battery Isolator Kit, 12V 80 Amp?: 2 stores we checked sell it, including Walmart, Amazon.