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
Type-C USB 1S 1A Lithium Battery Charging Module 18650 Li-ion Lipo Lithium Battery 3.7V 4.2V 2-Way Batteries Charger Protection
Aliexpress UK
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. When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery.
eBay
1S 2S 3S 4S 3A 20A 30A Li-ion Lithium Battery 18650 Charger PCB BMS Protection Board For Drill Motor Lipo Cell Module
Aliexpress UK
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. When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery.
eBay
Multi-Cell 2S 3S 4S Type-C To 8.4V 12.6V 16.8V Step-Up Boost LiPo Polymer Li-Ion Charger 7.4V 11.1V 14.8V 18650 Lithium Battery
Aliexpress UK
HEAVY DUTY BATTERY CABLE 300 or 485 Amp LIVE OR EARTH Power Inverter split charging system cable Starter, Alternators, Solenoid, Welding PVC Flex Cable Colours Red / Black 12 / 24 Volt Lengths and Amperage Choose from the drop-down menu 300Amp or 485Amp Will be supplied uncut Quality Flexible cable easy to cut Manufactured in the UK Plain Copper Conductors - PVC Insulated Manufactured in accordance with BS6862 Part 1 1971, where applicable. Plain copper conductors - PVC insulated -30C to +70C. Resistant to petrol, diesel, lubricating oils and diluted acids. Supplied From Half A Metre To A Full 10 Metre Roll Ideal for broken cut damaged leads or for upgrades Joining 2 battery's together and split chargers, Power Caps. Inverters Caravan, Motorhome, .
eBay
1.2V 12 Slots AA AAA Battery Charger Fast Charge Discharge Smart LCD Recharger for Ni-MH Rechargeable Battery
Aliexpress UK
485Amp Live Battery Power Lead Cable Sold by the Meter Max Reel Size = 10m Product Features: Multi Strand, Flexible Battery/Welding Cable 70mm2 Maximum Current: 485 Amp 12 / 24 Volt Length: 1 Meter Strands Diameter (0.292 STD): 0.285mmNom. Insulation thickness: 2.50mmApprox. Outer Diameter: 15.60mm Plain copper conductors - PVC insulated -30C to +70C. Manufactured in accordance with BS6862 Part 1 1971, where applicable. Resistant to petrol, diesel, lubricating oils and diluted acids. Sheath Colour: Red Finish Ideal for broken cut damaged leads or for upgrades Also a good car audio system power cable upgrade. Allows more flow of current to you car amplifiers. Double up on your earth straps and power cables will have a big impact if you are running a big sound .
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DIY for Qi Standard Wireless Charging Coil Receiver Module Circuit Board DIY Coil For Phone For Battery 5V 1A Fast Quick Charger
Aliexpress UK
6mm sq Red cable Power Feed (5m long). Also suitable for many other applications. The kit has everything that you need to install a split charging system in your vehicle including a relay that prevents your main battery from draining while the engine is stopped.
eBay
60V 67.2V 3A 5A 8A 10A Li-ion Charger 16S 60 V Lithium Battery Fast Charger 67V 60V5A GX16 XLR 3PIN IEC XT60 XT90 Alligator Clip
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
XT30 XT60 XT90 JST T Connector Lipo Battery Charger Board 2-6S Charging Board for Imax B6 B6AC IDST Q6 Lite Balance Charger
Aliexpress UK
Adaptive 3-phase Charging : Bulk, Boost, and Float. Maximum solar input current: 20A. Compatible with Multiple battery types : AGM, GEL, Flooded, and Lithium. 1 x 500mm RED 70amp READY MADE cable Relay to fuse holder lead.
eBay
67.2V 3A Li-ion Charger 16S 60V 60 Volt 10AH 20AH Lithium Battery Chargers T/PC/IEC 3Pin Connector With Fan
Aliexpress UK