Dual Battery Isolator Kit, 12V 140A VSR, 2m Cable

12V dual battery isolator kit helps keep your starter battery protected while charging a second battery automatically for accessories. This split charge relay uses a voltage-sensing relay (VSR) to connect at 13.3V and isolate at 12.8V, so power-hungry loads won’t leave you stranded. Built for RV, marine, truck, caravan, camper, and off-road setups, with a compact housing and IP65 protection for demanding environments.

• Delivers automatic dual-battery charging and isolation to protect starting power when the engine is off.


• Includes a 2m heavy-duty battery cable and complete accessories to reduce extra purchases and install time.


• Handles high current with 140A continuous / 160A intermittent capability for vehicle, marine, and workshop power builds.


• Resists water, dust, and vibration with an IP65-rated housing for boats, 4x4s, and harsh-weather use.


• Fits compact spaces and supports common 12V lead-acid systems (not suitable for lithium batteries).

Designed for quick-scan reliability, this voltage sensitive relay kit manages charging automatically—no manual switching—so your auxiliary battery is ready for fridges, lights, winches, and inverters while your primary battery stays ready to start. The rugged nylon plastic case and stainless M6 studs are built for real-world vehicle and marine installs, from camper vans and RVs to yachts and ATVs. Set up your dual battery system with the included components and get back to the road or water—grab yours today.

• System voltage: 12V DC


• Cut-in voltage: 13.3V


• Cut-out voltage: 12.8V


• Continuous current: 140A


• Intermittent current: 160A


• Standby current draw: 8mA


• Charging current draw: 280mA


• Delay time: 5 seconds; disengage delay: approx. 5–10 seconds


• Operating temperature: -30 to 105°C (-22 to 221°F)


• Ingress protection: IP65


• Material: nylon plastic


• Power studs: M6 stainless steel


• Cable length: 2 m


• Item size: 2.66 x 2.11 x 2.66 in (6.76 x 5.36 x 6.76 cm)


• Net weight: 4.14 lb (1.88 kg)