12V Split Charge Relay Kit, 140A VSR, 5m Cable

12V dual battery isolator kit keeps your starter battery protected while charging a second battery automatically for accessories, fridges, and winches. The voltage sensitive relay (VSR) engages at 13.3V and disconnects at 12.8V, so the batteries separate when the engine is off. Designed for tough installs with IP65 water and dust resistance and a complete 5m cable kit for cleaner wiring.

• Delivers automatic split charging for two 12V lead-acid batteries (not suitable for lithium).


• Protects starting power by isolating batteries when voltage drops to 12.8V.


• Includes a complete install kit with 5m heavy battery cable and necessary accessories.


• Handles high loads with 140A continuous / 160A intermittent VSR performance.


• Fits RV, marine, car, truck, camper, caravan, 4x4, ATV/UTV, boat, and workshop setups.

Built for real-world vibration, moisture, and dust, this compact voltage sensing relay kit installs neatly in tight bays and electrical lockers. Low standby draw helps reduce parasitic drain, while short engage/disengage delays smooth operation during charging changes. Use it to run auxiliary lights, inverters, comms, or camping gear without risking a no-start morning. Grab yours today and set up a reliable dual battery system before your next trip.

• System voltage: 12V DC


• Cut-in voltage: 13.3V


• Cut-out voltage: 12.8V


• Continuous current: 140A


• Intermittent current: 160A


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


• Current draw (standby): 8mA; current draw (charging): 280mA


• IP rating: IP65


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


• Material: nylon plastic


• Power studs: M6 stainless steel


• 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)


• Cable length: 5 m