---
product_id: 257387246
title: "MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit"
brand: "mayspare"
price: "€ 240.69"
currency: EUR
in_stock: true
reviews_count: 5
url: https://www.desertcart.gr/products/257387246-mayspare-dual-battery-isolator-kit-12v-140amp-voltage-sensitive-relay
store_origin: GR
region: Greece
---

# 140A Capacity 12V Power Complete Kit MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit

**Brand:** mayspare
**Price:** € 240.69
**Availability:** ✅ In Stock

## Summary

> 🔧 Power Up Your Adventures!

## Quick Answers

- **What is this?** MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit by mayspare
- **How much does it cost?** € 240.69 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/products/257387246-mayspare-dual-battery-isolator-kit-12v-140amp-voltage-sensitive-relay)

## Best For

- mayspare enthusiasts

## Why This Product

- Trusted mayspare brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **🌍 Global Reach:** Designed for international use with adaptable features.
- • **🔋 Dual Power Source:** Keep your main battery charged while powering accessories!
- • **⚡ Smart Voltage Control:** Automatically cuts in and out to ensure optimal battery health.
- • **🚗 Versatile Compatibility:** Perfect for ATVs, UTVs, boats, RVs, and more!
- • **🔌 All-Inclusive Installation:** Comes with everything you need for a hassle-free setup.

## Overview

The MaySpare Dual Battery Isolator Kit is a robust 12V, 140A solution designed to keep your vehicle's primary battery charged while allowing accessories to run off a secondary battery. With a smart voltage-sensitive relay that cuts in at 13.3V and out at 12.8V, this kit ensures your vehicle is always ready to go. Ideal for a variety of vehicles including ATVs, UTVs, boats, and RVs, it comes with all necessary components for easy installation.

## Description

MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit

## Features

- 12V, 140A, 13.3V cut-in voltage, 12.8V cut-out voltage,; Package Include All the Bits and Pieces Needed for a Complete Installation
- Working Voltage: Having Voltage Sensitive Chip,Rely Cuts in at 13.3 Volts and Cuts out at 12.8 Volts to Ensuring Primary Battery is Always Ready for Vehicle to Run.
- Fuction: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: This battery isolators are small and suitable for almost anywhere, for ATV, UTV, Boats, RV's?marine vehicle, truck, caravan
- International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Manufacturer | MaySpare |
| Brand | MaySpare |
| Package Dimensions | 31 x 21.6 x 7.7 cm; 1.88 Kilograms |
| Manufacturer reference | US-Battery kit |
| Exterior | Metallic Finish |
| Manufacturer part number | US-Battery kit |
| Lift type | Automatic |
| Amperage | 140 Amps |
| Voltage | 12 Volts |
| Item Weight | 1.88 kg |

## Product Details

- **Connector Type:** Screw
- **Contact Material:** Silver
- **Contact Type:** Normally Open
- **Current Rating:** 140 Amps
- **Mounting Type:** Panel Mount, Surface Mount

## Images

![MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit - Image 1](https://m.media-amazon.com/images/I/71hE4P1kgzL.jpg)
![MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit - Image 2](https://m.media-amazon.com/images/I/71Lrh+Qt1pL.jpg)
![MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit - Image 3](https://m.media-amazon.com/images/I/81cQfu+vzUL.jpg)
![MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit - Image 4](https://m.media-amazon.com/images/I/71pkOcrZYPL.jpg)
![MaySpare Dual Battery Isolator Kit 12V 140Amp Voltage Sensitive Relay VSR Double Battery Automatic Charger & Wiring Cable Kit - Image 5](https://m.media-amazon.com/images/I/71aam77QIVL.jpg)

## Questions & Answers

**Q: what type of power runs continuously from the start battery to auxiliary to charge it through the cable???**
A: When the isolator reads the need to charge the second battery it will be charged with the alternator of the vehicle

**Q: Does this item have an internal fuse? Do I only need to fuse my auxiliary battery?**
A: No it does not.  I highly recommend installing a re-settable 150A fuse between your main battery and the isolator.

**Q: are the cables copper clad aluminum or all copper?**
A: Copper

**Q: Can I use this to connect 2 RV batteries in parallel with differet amperage so that the leisure battery only kicks in when the primary battery low?**
A: So they are connected in parallel when charging. The batteries can be of different amperages. However if the non stater battery drops below 12.8 volts it will disconnect from the system so your starter battery does not discharge. Starter and non-starter battery connections are labeled. The yellow wire coming out of the controller can be connected to a switch with the other side connected to ground. If you move the switch so yellow wire goes to ground it will bypass the disconnect and connect both batteries in parallel regardless of the voltage of either battery. Hope this helps.

## Customer Reviews

### ⭐⭐⭐⭐⭐ 







  
  
    Great Product Quality, Easy to Install
  

*by T***K on Reviewed in the United States on 17 July 2022*

This seller makes a great product.  All the hardware and wire necessary to install the dual power isolator.  Good instructions.  I ran the dual power isolator to a AGM power box in the passenger floor area of my Dodge Caravan.  Wanted to be able to monitor the isolator and connected a voltage meter to monitor the main battery and auxiliary battery.  The gauge of wire is right and everything is working great.  I glad I bought this product.

### ⭐⭐⭐⭐⭐ 







  
  
    Works well
  

*by C***. on Reviewed in Canada on 18 October 2020*

Very pleased came with everything I needed to install a second battery in my kawaski teryx for running all my accessories

### ⭐⭐⭐⭐ 







  
  
    Works
  

*by S***E on Reviewed in the United States on 10 October 2023*

Easy install pretty straight forward and works

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**Shop now:** [https://www.desertcart.gr/products/257387246-mayspare-dual-battery-isolator-kit-12v-140amp-voltage-sensitive-relay](https://www.desertcart.gr/products/257387246-mayspare-dual-battery-isolator-kit-12v-140amp-voltage-sensitive-relay)

---

*Product available on Desertcart Greece*
*Store origin: GR*
*Last updated: 2026-03-10*