When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery. So it does not drain your main starter battery and you will always be able to start your vehicle.
eBay
TOPK Air Vent Car Mount,[Big Phones&Thick Case Friendly]Cell Phone Holder for Car Hands Free Clamp Cradle Vehicle for All Phones
Aliexpress UK
IP67 rated waterproof junction box and solar connectors, suitable for outdoor. Withstand up to 5400 Pa of heavy snow load and up to 2400 Pa of high wind. Excellent Quality.
eBay
LED Red and Blue Multifunction Flashing Warning Light Waterproof Traffic Safety Shoulder Light Manual Control Built-in Battery
Aliexpress UK
Built-in LED indication (lights up when VSR starts). Automatically combines two batteries when charging and isolates the two batteries when not charging,which can widely used in 12v camper van trucks, caravans, and camping applications.
eBay
5000RPM 150mm Cordless Polisher 6Gears Rechargeable Car Polishing Machine Electric Rotary Tool For Makita 18V Battery(NoBattery)
Aliexpress UK
When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery. So it does not drain your main starter battery and you will always be able to start your vehicle.
eBay
6.3 inch Purple LED Letter Light Warm Light Alphabet Number Luminous Letter with Battery for Home Decoration Light Used for Pr
Aliexpress UK
High Quality: This Battery Isolator is made of ABS material ,supports long service life. and also can be effectively waterproof and dustproof. 1 Battery isolator. Cut-out Delay: 3-5 Seconds. Current Draw: Charging 250 Amp, Standby 10mA.
eBay
TOPK Car Phone Holder Mount Air Vent Cell Phone Holder for Car Hands Free Easy Clamp Cradle in Vehicle Fit All 4" to 7" Phone
Aliexpress UK
Ideal for Caravans, Campers, House and leisure boats Very easy installation, two fixings and three wires. Black to Chassis of vehicle (Earth) plus one wire to Leisure battery + and one to Engine battery plus!
eBay
Wireless Doorbell Smart Home Welcome Door Bell 36 Ringtones 300M Long Distance Outdoor House Door Chime Kit Battery Free
Aliexpress UK
WERCHTAY 12V 100Ah LiFePO4 Lithium Battery for RV Camper Marine 100A BMS Power Trolling Motor Solar Generator 25000 Cycles. Capacity: 100Ah. 12V 100Ah: 260 168 215mm, 10kg. Continuous Current: 100A. Material: lithium iron phosphate.
eBay
LED Fairy Lights Button Battery Light String Christmas Wedding New Year Bedroom Living Room Garden Decoration Garland
Aliexpress UK
When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery. So it does not drain your main starter battery and you will always be able to start your vehicle.
eBay
40A MIDI FUSE KIT 4 ANS Holder 7 X 40 AMP Fuses Midi Fuses Kit For Redarc BCDC Dual Battery Car Accessories
Aliexpress UK