Anderson Plugs
An Anderson Plug is an integral part of a specialised charge circuit – the socket on the end of the leads. It essentially allows the passage of charge from the vehicle’s battery to pass through to an in-board one in the caravan. In effect they are exactly the same as the dual battery system you’ll find fitted to many 4WD vehicles, and whilst they are in fact properly Charge Circuits, they have have come to be known by the more common name, Anderson Plug Circuits.
There are two options when it comes to charging circuits in your rig:
12 Pin Plug

12-pin plug with medium charge wires
Anderson Plug

Anderson Plug with large charge wires
Often you will have a choice between having a separate plug for your system, or a fully self-contained arrangement (12-pin plug). A drawback of the 12-pin arrangement is that it only has the capacity for medium-gauge wiring, whereas the Anderson system can accept much thicker gauge wires. This in effect means you’ll be able to pass more charge through to the caravan’s battery system.
Anderson Plug System and Requirements
Anderson Plug Circuit
This circuit is incredibly simple. Generally it will have a pair of large-gauge wires, often around 6 B&S (around 13mm OD) and consist of a run from the vehicle’s battery directly through to the caravan’s, via a circuit breaker arrangement and Anderson plug. Anderson plugs are typically grey in colour and are the same in both plug and socket form. A battery which is low on charge can be much more effectively boosted using this setup as the heavier gauge wire allows much freer passage of current.
12 – Pin Socket
This option is more appropriate where only one socket is available or where caravanners are looking to minimise work. As this style can only carry 6mm gauge wiring at most, it cannot give the same charge capacity as the Anderson option. Also, due to limitations of the pins themselves in this socket style which further decreases charge output. However, this system has a major advantage in that it is incredibly simple.
Comparison of Anderson Plug and 12-pin Socket Systems
Requirements
12-Pin Plug
6mm Wire on Anderson Plug
13mm Wire on Anderson Plug
Some charge to the battery but need simplicity on hookup.
Best Option
Want to maximise charge to caravan battery.
Best Option
Caravan already has Anderson Plug.
Best Option if 6mm wire
Best Option if 13mm wire
Caravan already has 12-Pin plug.
Best Option
