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
Probty USB-C Camera Battery Charger for Ricoh GRIV GR IV Ricoh GR4 Battery Charger Ricoh DB-120 Charger with Charging Cable
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
4 Slots USB Charger Li-ion Charging 4.2V Li-ion Battery 2X 3X 4X Portable Rechargeable Battery Charger For 18650 Battery Charger
Aliexpress UK
Maximum solar input current: 20A. 1 x 500mm RED 70amp READY MADE cable Relay to fuse holder lead. 2 x 250mm RED 70amp READY MADE cable from Battery to fuse holder lead. 2 x MTA MIDI Fuse holders. The kit includes everything you need for setup dual battery charging system .
eBay
Universal Button Battery Charger LED Indicator Portable Type C Charger For LIR2016 LIR2025 LIR2032 Battery Charger Accessories
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
58.8V 5A Lithium-ion Charger Usd For 51.8V 14S Battery Charger With OLED Display Fast Charger
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
For Bosch Battery Charger AL1820CV AL1814CV Replacement Battery 18v for Bosch and Charger BAT609 BAT614 BAT618 14.4V-18V Charger
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
29.4V Charger 4A Lithium Battery Wheelchair Fast Charger For 24V 7Series Li-ion battery pack Lithium Battery Charger XLR RCA
Aliexpress UK
Dual Battery Isolators also feature surge protection and a L.E.D indicator designed to alert the user when the unit is engaged. When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery.
eBay
KEBIDU 18650 Battery Charger 2/4 Slots DC 5V Charger For 18650 14500 10440 Battery 3.7V Rechargeable Lithium Battery Charger
Aliexpress UK
Maximum solar input current: 20A. 1 x 500mm RED 70amp READY MADE cable Relay to fuse holder lead. Compatible with Multiple battery types : AGM, GEL, Flooded, and Lithium. 2 x 250mm RED 70amp READY MADE cable from Battery to fuse holder lead.
eBay
58.8V 5A Charger 14S 52V Li-ion Battery Charger Lipo/LiMn2O4/LiCoO2 Charger Output DC 58.8V With cooling fan
Aliexpress UK