ANDERSON PLUGS ARE ESSENTIAL FOR EFFICIENT CHARGING
In a caravan or camper trailer, where they have either a battery that requires charging or a fridge that operates off a 12V supply, an Anderson Plug is essential. Some 12-pin plugs do offer the same service but can only take a maximum cable diameter of 6mm.
Both your fridge and battery charge are highly voltage dependent. A 10 per cent voltage drop at 240V AC will barely register but if you’re running on 12V DC, the battery won’t charge properly and the fridge will start to have problems, especially if it’s a compressor. Battery charging voltage should be around 13.9- 14.5V DC.
ANDERSON PLUGS REQUIRE THE CORRECT SIZED CABLE
Anderson plugs are available in various current ratings (50A, 120A and 175A) and can accept very large cables, but it’s critical to ensure you use the correct cable size. Auto cable used in Australia is deceptive because the diameter size it’s sold under often includes the insulation.
Calculating cable size uses voltage drop, cable length and expected load current, so it will vary from installation to installation.
6B&S is often recommended to cover most situations but it’s a hefty bit of cable.
There is also some debate about whether cable connections should be soldered or crimped or both. However, the recommended technique is crimping using quality cable lugs and a good crimping tool, which ensures a good connection at all times.
ANDERSON PLUGS HAVE MANY OTHER USES
Many people assume that Anderson plugs are only useful to create a connection between a tow vehicle and a caravan or camper trailer – but they have other uses as well. Anderson plugs used to be very expensive (hence their limited use) but they are less expensive now, so they’re becoming more popular to connect a portable fridge inside a tow vehicle/camper or used as a remote connection for a free-standing solar panel. They can even be used by charging sources other than the tow vehicle. In all cases, they are designed to minimise voltage drop and create an easy connection.
ANDERSON PLUGS SHOULD BE TREATED WITH CARE
Anderson plugs are quite robust but they should always be treated with care. Avoiding dropping the plug into dust or mud and don’t leave it where it can be stepped on. Visually check the contacts from time to time to ensure a reliable connection every time you use it. If mechanical damage does occur, it should be checked for any insulation breakdown or shorting out before use.
ANDERSON PLUGS ARE SIMPLE TO FIT
I once saw a suggestion for charging a fridge, which involved using an inverter connected to a multi-stage charger which, in turn, was connected to the caravan battery. There are several problems with this idea – safety and energy loss being just two of them. One of the benefits of the Anderson plug is that the cable from the Anderson plug runs directly to the tow vehicle battery. It should be correctly fused, of course, but it’s fairly simple to install.
Mechanical protection is often the most difficult problem – where the cable runs through metal holes it can chafe but, apart from that, it is not too difficult to install an Anderson plug.
MEET THE AUTHOR
Malcolm Street began caravanning in the early 1970s, first in a Viscount and later in a York, the former towed by a Holden Kingswood. Malcolm has RV’d extensively across Australia, New Zealand and Britain. He became an RV journalist in 1999. Each year, he reviews around 40 caravans and motorhomes in Oz and NZ. Yes, he’s a well-travelled bloke with no shortage of campfire opinions about how a given caravan could be better put together.