3UA59 00-1C.
eBay
Solid State Relay Module SSR 10-100 amp Single Phase DC-DC 3-32V DC to 5-220V DC. - Heat Sink Type A: Suitable for a single solid state relays with load current of 10-25 amp. - Heat Sink Type A(Black): Suitable for a single solid state relays with load current of 10-25 amp.
eBay
The maximum instantaneous current can pass 500A. Max switching current: 500A. - High quality 4 pin, fused (ON/OFF) relay switch. 1x 4 Pin Over 500A12V Relay On/Off Car Auto Power Switch. Rated power: 12V.
eBay
Heavy duty 100 Amp 12 volt relay Ideal for split charging systems or heavy load switching. 30 - FUSED FEED FROM BATTERY POWER. 86 - IGNITION FEED.
eBay
~~ 4x 12 Volt 30 Amp Relay ~~. Suitable for many applications.
eBay
These are heavy 80A relays. Max switching current: 80A. Max switching capacity: 80A. 2 x 80A relays with socket. 12 volt 80 amp 5 pin relay socket. Coil resistance (1.8W): 80. Vibration Resistance: 10~55Hz, 1.5mm.
eBay
eBay
It simply connects between the two batteries. The relay is connected between the vehicles main battery (Positive) and the leisure battery (Positive). The most important part of the circuit are the fuses!
eBay