Smart 12V 140A Dual Battery Isolator Kit with LCD Voltmeter & VSR Relay for RV, Marine & 4WD Off-Road

Smart 12V 140A Dual Battery Isolator Kit with LCD Voltmeter

If you are running an auxiliary fridge, extra lighting, or onboard gear in your 4WD, camper van, or boat, managing your power setup shouldn't be a guessing game. This 140 Amp dual battery isolator kit takes care of the charging automatically—hooking up your auxiliary battery when the engine runs and safely isolating your starter battery so you never get left stranded.

Why DIYers Choose This Setup

• Real-Time Dual Voltage Readout: The crisp LCD screen lets you check the exact voltage of both your main and auxiliary banks at a quick glance, making it easy to spot charging issues before they leave you stuck.
• Manual Override Mode: Got a flat starter battery after a long night off-grid? Flip it to manual mode to draw power back from your house battery and crank the engine without dragging out jumper cables.
• Smart Delay Protection: It features a built-in adjustable delay (3 to 60 seconds) so the relay doesn't chatter or trip out every time your alternator fluctuates during heavy engine startup.
• Built for Tough Conditions: Housed in a heavy-duty, weather-resistant shell designed to handle engine bay heat, vibration from corrugated dirt roads, and salty marine air.
• Works with Most Chemistries: Fully compatible with standard Lead-Acid, AGM, Gel, and modern LiFePO4 lithium batteries.

What's in the Box

• 1 x 12V 140A Smart VSR Dual Battery Isolator with LCD Screen
• 1 x Complete Wiring & Terminal Installation Kit
• 1 x Setup & Wiring Guide

<h3>Technical Specifications</h3>
<ul>
  <li><strong>Nominal Voltage:</strong> 12V DC</li>
  <li><strong>Continuous Current Rating:</strong> 140A</li>
  <li><strong>Intermittent Current Rating:</strong> 170A</li>
  <li><strong>Cut-In Voltage:</strong> 13.3V DC (charges auxiliary battery once starter battery is healthy)</li>
  <li><strong>Cut-Out Voltage:</strong> 12.8V DC (automatically isolates starter battery to prevent drain)</li>
  <li><strong>Standby Current:</strong> &lt; 10mA</li>
  <li><strong>Protection Rating:</strong> IP65 Weatherproof (resists marine spray, dust, and vibration)</li>
  <li><strong>Terminals:</strong> M6 (1/4") heavy-duty brass studs</li>
  <li><strong>Compatibility:</strong> Lead-Acid, AGM, Gel, and compatible 12V auxiliary banks</li>
</ul>

<h3>Wiring &amp; Installation Guide</h3>
<ol>
  <li><strong>Terminal 1 (Start Battery):</strong> Connect heavy-gauge positive cable from the primary starting battery positive (+) terminal.</li>
  <li><strong>Terminal 2 (Auxiliary Battery):</strong> Connect heavy-gauge positive cable to the secondary/auxiliary battery positive (+) terminal.</li>
  <li><strong>Ground Lead (Black Wire):</strong> Connect the thin black ground wire to the vehicle chassis or common negative (-) terminal.</li>
  <li><strong>Recommended Protection:</strong> Install a 150A inline fuse or circuit breaker within 20 cm (8 in) of each battery positive terminal.</li>
</ol>

<h3>LED Status Indicator</h3>
<ul>
  <li><strong>Solid Red LED:</strong> Relay engaged — alternator is actively charging both start and auxiliary batteries.</li>
  <li><strong>LED Off:</strong> Relay disengaged — batteries are completely isolated to preserve starter battery charge.</li>
</ul>