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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can replace AG13 LR44 LR1154 primary new button cell, 3PCS * ZH40H rechargeable button cell+charger set
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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. 3m kit includes everything you need for setup dual battery charging system .
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XH-M601 Intelligent Charger Power Control Panel Automatic Charging Power 12V Battery Charging Control Board For Diy Kit
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
XH-M601 Intelligent Charger Power Control Panel Automatic Charging Power 12V Battery Charging Control Board For Diy Kit
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
1-10PCS DC-DC Boost Module Type-C TP4056 Charger Discharge Power Board DC4.3-27V Charging Step Up Boost Module DIY Kit Parts
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
7.4V 600mAh 25C Lipo Battery Charger set for XK DHC-2 A600 A700 A800 A430 2s Replacement Battery for WLToys F959 RC Airplane RTF
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
36V/48V 20Ah Battery 18650 Lithium Rechargeable Battery Built-in Bms for Silverfish 250W-1000W Bafang Motor Kit with 2A 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
1900mah 7.4V LP-E8 LP E8 Batteries LPE8 Battery LED Dual Charger set for Canon EOS 550D 600D 650D 700D X4 X5 X6i X7i 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
3.7V 1200mah lipo battery and charger set for SP650 aerial photography UAV quadcopter spare parts RC helicopter battery
Aliexpress UK