The right way to install 12v gear, and how to avoid the most common mistakes 4WDers make.

“THE NUMBER ONE CAUSE OF 12V PROBLEMS CAN BE FIXED FOR $10!”

DOWN TO EARTH

Let’s talk about this one first because it’s so incredibly important. Without proper earthing, any 12v system is going to fail. Earthing completes the 12v circuit back through the body and the chassis and finally back to the battery. One of the biggest mistakes 4WDers make is not ensuring adequate earth connections are built into the system.

The good news is the number one cause of 12v problems can be fixed for $10 by adding an extra earth to your vehicle. It’s as simple as running cabling from your battery’s negative post through to a good clean, unpainted earth point on the body. At the same time, remove the big earth lead that runs from the negative battery post to the side of the engine block, and use sand-paper to thoroughly clean the lugs and the earth points. If you’re running batteries in the rear of the vehicle, don’t rely on running earth cables all the way to the engine bay – add an extra earth to the chassis somewhere in the rear. You can never have too many earths!

WHERE TO MOUNT YOUR CHARGER

Heat and dirt are the natural enemy of electrical components. Unfortunately, both are in abundance under the engine bay. If you install it under the bonnet near hot engine components, this can reduce the performance of the charger. If the charger has a temperature compensator built in, it will reduce the charge level to compensate for the heat. So when you mount your CTEK D250SA, make sure it is away from any heat source, like in the back of your 4WD.

That’s not to say you can’t run 12v equipment under the bonnet, just that you need to be aware of where it is positioned. Keep chargers away from hot exhaust manifolds and turbos, and up towards the rear of the engine bay if possible to protect from mud.

CHOOSING THE RIGHT CHARGER

Dual battery systems aren’t all built alike. DC/DC chargers like the D250SA from CTEK are ‘smart’ chargers that can intelligently charge the battery the way it needs to prolong battery life. They can also protect the battery by monitoring temperatures and adjusting charging levels to prevent over-charging, and can include a solar regulator to let you charge batteries either via the alternator or a solar panel.

At the end of the day, it doesn’t matter if you’ve got the best system in the world, if you don’t drive it enough. Your alternator can only put out so much output, so the longer you drain your batteries, the more time you need to recharge them.

Most alternators will put out somewhere between 60 and 100amps. That doesn’t mean they’re putting that many amps into the battery, though. When the vehicle’s running a large portion of the alternator’s output is taken up by the vehicle’s electrical system, the ignition system, the headlights, the stereo, the heater/air conditioning system and the like. That means the rate your battery charges at isn’t an exact science. A safe rule of thumb to recharge a single auxiliary battery after a night running the fridge is about three hours to ensure complete recharging.

“ONE OF THE BIGGEST MISTAKES 4WDERS MAKE IS POOR EARTHING”

THE REAL DEAL WITH SMART ALTERNATORS
PLUS AN EASY, CHEAP SOLUTION ANYONE CAN INSTALL!

You might have heard about the term ‘smart’ alternators. Basically, these are alternators that don’t always provide the full level of output but rather vary their output depending on battery levels and load requirements. The general idea is that if the alternator doesn’t have to work at full capacity the whole time, it’ll save (very small) amounts of fuel by reducing load on the engine. The problem for 4WDers is that it means the alternator won’t always produce enough charge to properly charge an auxiliary battery.

LOW-GRADE GEAR

There’s nothing more frustrating than completing a 12v install and having it not work properly. The problem comes down to using lower-grade gear throughout the system.

The biggest mistake 4WDers make when they install their 12v system is using low-grade plugs, terminals and connectors, plus under-sized wiring, especially from the battery to the charger. Reliability in off-road environments is crucial, but this can be sacrificed with cheap parts that won’t stand up to vibrations, dust, heat and water.

The simple message here is don’t cut corners. There’s no point trying to save a few bucks on cabling if it compromises the rest of your $500 system – which brings us to our next point, calculating wiring requirements.

CALCULATING CABLING REQUIREMENTS

The cabling that you use in your 12v installs can make or break your setup. Voltage drop is one of the single biggest causes of batteries that won’t charge properly and fridges that continually blink that error light. If your cabling is too small, it simply won’t be able to carry the power required through it. The good news is that there are ways to calculate the cabling you need. It’s also always much better to over-estimate your power needs and run bigger cabling rather than under-sized stuff. Here’s a quick guide for the most common installs.

Remember – if in doubt, it’s always better to run over-sized cable than undersized stuff!

GET THE MOST FROM YOUR SOLAR SETUP

Solar power has taken off in a massive way in the last couple of years, letting 4WDers camp for longer without having to drive to recharge batteries.

To get the most from your solar setup, first you need to make sure the regulator is big enough, There are two main types of regulators used – Pulse Width Modulation or PWM and Maximum Power Point Tracker or MPPT. A PWM type cuts down the input voltage to the charge voltage and ‘burns’ off excess voltage. An MPPT type regulator like the Adventure Kings MPPT Regulator uses all the available voltage to insure the most amount of current is getting to the batteries. It does this by monitoring the power and voltage from the panels and adjusts panel voltage for maximum power accordingly. In general, an MPPT type regulator will improve the amount of power extracted from your panels by up to 30%.

ARE YOU RUNNING THE WRONG BATTERY?

The most common batteries for 4WDers are still Wet Cell and AGMs, like the Adventure Kings AGM Battery. Wet Cell (Calcium), AGM, Gel, Lead Crystal and Lead Carbon are all Sealed Lead Acid (SLA) batteries with the major component being Lead. Most conventional smart chargers can charge these types of batteries.