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.
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Epever Duo Racer MPPT Solar Controller 20A 30A Solar Charge Dual Battery 12V/24V Remote for Campe DR2210N-DDS DR3210N-DDS
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. - Suitable for most 12V charging systems- Surge protection. When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery.
eBay
100A 230VDC MPPT Solar Charge Controller 12V 24V 48V 96V Auto Solar Panel Regulator For Lead Acid Lithium Lifepo4 Battery
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
12V Battery Charge Protective DC 12V 20000mAh Lithium Polymer Super Rechargeable Battery Backup Li-ion 12V Battery Pack
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
PowMr MPPT 60A 40A 30A 20A LCD Solar Charge Controller 12V 24V 36V 48V Auto Battery Solar Panel Smart Regulator Support Lifepo4
Aliexpress UK
Note: The benefit of this type of relay is that it does not require a connection to the alternator or any modifications to the existing vehicle electrical system. The location is very good.
eBay
EPever MPPT 40A 30A 20A 10A Solar Charge Controller 12V 24V Auto Solar Panel Regulator Solar Battery Charger Tracer3210AN 4210AN
Aliexpress UK
Working principle: When the engine is turned off, the relay will isolate your leisure battery from the main starter battery. Therefore, it will not drain the battery of the main starter and you will always be able to start the vehicle.
eBay
Solar Charge Controller MPPT 30A 40A 50A 60A 80A 100A LCD Display 12V 24V AUTO Dual USB Solar Charge And Discharge Controller
Aliexpress UK
Suitable for most 12V charging systems- Surge protection. 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
10A MPPT Solar Charge Controller 12V/24V Automatic Solar Panel Charge Regulator And Bluetooth Combination
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. - Suitable for most 12V charging systems- Surge protection. When your engine is switched off, the relay will isolate your leisure battery(s) from your main starter battery.
eBay
MPPT 1A LiPo Solar Charge Controller Board Battery Charge for Arduino Solar Panel Charger Regulator Control Module 9V 12V 18V
Aliexpress UK