what type of power runs continuously from the start battery to auxiliary to charge it through the cable???

When the isolator reads the need to charge the second battery it will be charged with the alternator of the vehicle

Does this item have an internal fuse? Do I only need to fuse my auxiliary battery?

No it does not. I highly recommend installing a re-settable 150A fuse between your main battery and the isolator.

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?

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.

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

Product ID: 173975296

Details

Connector Type
Screw
Contact Material
Silver
Contact Type
Normally Open
Current Rating
140 Amps
Mounting Type
Panel Mount

⚡140A Capacity

🔋12V Power

🔌Complete Kit

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$129.89

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Description

🔧 Power Up Your Adventures with Confidence!

🌟 PREMIUM SUPPORT - We're here for you—reach out anytime for assistance!
⚡ SMART VOLTAGE CONTROL - Automatically cuts in at 13.3V and out at 12.8V for optimal performance.
🔋 DUAL POWER MANAGEMENT - Effortlessly manage two batteries for uninterrupted power.
🚗 VERSATILE COMPATIBILITY - Perfect for ATVs, UTVs, boats, RVs, and more!
🔌 ALL INCLUSIVE INSTALLATION - Comes with everything you need for a hassle-free setup.

The MaySpare Dual Battery Isolator Kit is a robust 12V, 140A solution designed to keep your primary battery charged while allowing accessories to run from a secondary battery. With a smart voltage-sensitive relay that cuts in and out at precise voltages, this kit ensures your vehicle is always ready to go. Ideal for a variety of vehicles, it includes all necessary components for easy installation and is backed by premium customer support.

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Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

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