UCkasayfy Dual Battery Isolator 12V 140A VSR with Voltage Display, IP67 Waterproof

UCkasayfy Dual Battery Isolator Kit is a 12V, 140A voltage-sensitive relay (VSR) that automatically manages charging between a main and auxiliary battery to protect and preserve vehicle power.

This smart battery isolator kit is designed to keep your primary battery reserved for starting while allowing an auxiliary battery to be charged when the alternator output reaches a safe level. It combines an easy-to-read voltage display with IP67-rated protection and automatic disconnect thresholds, making it suitable for a wide range of recreational and work vehicles. Note: this model is not compatible with lithium batteries.

How does the UCkasayfy VSR protect my starter battery?

The built-in voltage-sensitive relay connects and disconnects batteries based on real-time voltage so the starter battery stays prioritized. When alternator voltage rises above the set cut-in, the relay links the batteries to charge the auxiliary unit; it opens the circuit below the cut-out to isolate the starter.

• Cut-in voltage: 13.3 V to engage charging
• Cut-out voltage: 12.8 V to protect starter reserve
• Automatic operation—no manual switching required for normal use
• Visible voltage readout for quick monitoring

What safeguards keep the isolator and batteries safe?

The unit automatically disconnects if input voltage goes outside safe bounds, preventing damage from over-voltage or deep discharge. Its IP67 rating guards the electronics from water and dust, so the isolator performs reliably in wet or dusty conditions commonly found on boats, off-road vehicles, and trailers.

• Auto disconnect below 11 V and above 17 V for battery protection
• IP67 waterproof and dustproof enclosure for harsh environments
• Thermal and electrical protection built into the relay circuitry
• Durable construction for long-term, low-maintenance use

Can I use the kit for emergency charging or reverse charging?

Yes — the UCkasayfy isolator supports both automatic and manual modes that allow reverse charging when needed. In an emergency, switching to manual ties the auxiliary and main battery together so the auxiliary can help start or top up the main battery.

• Manual override to connect batteries for emergency assistance
• Automatic mode restores standard protection once voltages normalize
• Useful for jump-starting from an onboard auxiliary battery
• Clear status indication to confirm connection mode

Where is this battery isolator best applied?

The UCkasayfy 140A VSR is intended for vehicles and craft that use conventional lead‑acid or AGM auxiliary batteries. It’s built for installs where reliable automatic charging management, rugged weather resistance, and visible voltage feedback matter most; it is not suitable for lithium battery systems.

• Fits ATVs, UTVs, cars, trucks, trailers, RVs and marine vessels
• 140A continuous handling for moderate charging demands
• Compact form factor for easy mounting in engine bays or battery compartments
• Voltage display helps diagnose charging at a glance

Who is this for: Owners of recreational vehicles, boats, campers, trailers, and off-road machines who use conventional lead-acid or AGM auxiliary batteries and want an automatic, low‑maintenance way to protect their starter battery while still charging accessories. Choose this unit if you need a weatherproof, user-friendly isolator with emergency reverse-charge capability and clear voltage feedback. Do not use this isolator with lithium battery types.