If you’ve ever spent time around a toddler, you’ve probably witnessed the so-called Terrible Twos. Experts say the tantrums stem from young children trying to figure out their place in the world while lacking the communication skills to explain what they’re thinking. The result is an incoherent, wildly unreasonable little person whom you’re somehow expected to be endlessly patient with.

Well, guess what? 4WD Revolution turns two this month, and I’m about to ask you to do the same.

About six months ago, I wrote an editor’s column asking for your feedback. I wanted to know what you liked, what you didn’t and—most importantly—what direction you thought the magazine should take.

It took me weeks to reply to everyone. Not just because there were so many emails, but because I wanted to give each response the same level of thought that many of you had put into your feedback.

What surprised me wasn’t the number of responses. It was how similar they were.

A clear pattern began to emerge.

PATTERN RECOGNITION

Time and again, readers said they valued in-depth, well-researched articles that offered practical advice rather than superficial content. Many of you also told me you were collecting the magazines and keeping them on file as a reference.

That felt important somehow, but much like a two-year-old trying to explain why he absolutely must wear gumboots to bed, I couldn’t quite articulate why.

Then, one afternoon, it finally clicked.

This isn’t becoming a magazine.

It’s becoming a library.

That realisation changed things.

Readers aren’t simply reading 4WD Revolution. They’re using it as a reference. And that’s when I realised we’d created an unexpected problem.

A reference guide is only as good as its index. So, if the information you’re looking for is scattered across half a dozen back issues, it isn’t really a guide at all. It’s just a collection of magazines, and finding the answer becomes an exercise in frustration rather than a genuinely useful resource.

So I started asking a different question.

Not, “How do we build a better magazine?”

But rather…

“How do we build something that’s genuinely more useful?”

The answer, I think, is surprisingly simple.

Don’t build a magazine. Build a library.

After all, a magazine is something you read once. A library is something you can return to.

Caption: Over time, we’ll continue adding old and new features to their relevant categories, making it easier to find useful stories when researching a topic. But more than that, we want to include your experiences, too. If you’d like to contribute to a topic, get in touch with us here.

THE COMPOUND EFFECT

In practical terms, that means we’re moving away from producing dated PDF issues and towards publishing articles as they’re completed. Instead of waiting months for the next issue, you’ll receive new stories throughout the year. The best of them will be continually expanded, refined, and woven into dedicated topic guides which become more comprehensive with every update.

Over the coming months, you’ll start seeing that vision take shape. So rather than producing PDF magazines that slowly become yesterday’s news, I want us to build something that becomes more valuable with time.

Every new article, every reader contribution and every fresh piece of research should strengthen the articles that came before it.

I’ve been writing about 4x4s for almost 20 years, and in that time I’ve been constantly reminded of two things: how much I still have to learn, and that our collective knowledge is far greater than any one person’s.

That’s the future I want to build.

And if your emails and contributed stories are anything to go by, I have a feeling it’s one we’ll build together.

You can start by contacting us here.

The post GROWING PAINS appeared first on 4WD Revolution.

I tend to gauge 4×4 equipment in a cost-versus-reward ratio.

For example: The cost of a recovery winch is high relative to how often you’ll use it, but in the event of you desperately needing one, the price is irrelevant.

This is true for many accessories: Bull-bar, long-range tank, suspension, Light Truck tyres, a diff-lock… it’s a long list.

However, there are one or two accessories on the market where the costs are crazy low, despite the benefits being incalculably high. Namely: a winch damper! Otherwise known as a ‘winch blanket’.

So what does a winch damper do, and, how do you use it properly?

Let’s delve into it… 

WHAT DOES A WINCH DAMPER DO?

In short, the purpose of a winch damper is simple: In the event of your winch cable (or snatch strap) breaking under load, the winch damper is designed to weigh the cable down so that it hits the ground and reduces its speed and kinetic energy, while directing any potential impact forces away from the vehicle.

Without a winch damper you run the risk of the broken cable or strap causing significant damage to the recovered vehicle, or worse yet, resulting in a life-threatening injury.

DO WINCH DAMPERS WORK?

But do winch dampers really work, or are they just gimmicky items that take up space in your recovery bag?

Well, the answer to that question depends on three things:

• The quality of the winch damper
• Where you position it on the cable
• How many winch dampers you use

It would be easy to assume that any item could be flopped over a winch cable to dampen its forces, but it’s not uncommon for a low-quality winch damper to tear apart in a recovery situation. This is particularly true for broken snatch straps which release incredible amounts of energy once they fail.

That said, it’s quite likely that most winch dampers (even the good ones) will rip in the event of a broken cable or strap, but what you don’t want is for the bag to be easily flung off the cable when that happens. The damper needs to stay on the cable long enough to drag it to the ground.

On that note, the effectiveness of a winch damper radically improves the moment it’s filled with sand or dirt. Which is why the bag you purchase should include a pocket(s) of some sort

SAFETY TIP: Never fill the pocket with rocks, as this could turn the bag itself into a dangerous projectile.

HOW TO USE A WINCH DAMPER

The obvious question is: Where do you place the bag over the cable, at the front, rear, or in the middle of the cable’s length?

There’s some debate around which position works best, but it’s widely accepted that the best place to position your winch damper is somewhere between the middle- and the far-end of the cable. This is because most cables typically fail close to the “hook up” point. Or at least: within the last third of the cable’s length.

Ideally, the more dampers you use, the better the result. So from that perspective, the more the merrier.

However, what matters most is that you don’t rush the recovery process, and that you take the time to assess the situation. At the end of the day, getting home safely is your number one priority.

More winch-damper tips from SecureTech

1. Never overfill the bag as the stitching may fail during a “normal” recovery.
2. Failure to fill the bag with enough sand or dirt may significantly reduce its effectiveness. That said, winch dampers with small pocket sizes are generally ineffective.
3. We recommend that a winch damper be used on either end of the recovery system. We generally spec one damper (@ 5m) from each vehicle, and an additional damper along each 5m interval if the rope/cable/strap is long enough.
4. We prefer using our winch dampers in conjunction with safety lanyards.
5. SecureTech winch blankets can also be used with kinetic ropes, webbings, winch extension strap, pull straps, winch cables, and plasma ropes.

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The post Do winch dampers work and how to use them properly appeared first on 4WD Revolution.

Last month we chatted about steel rims vs alloy rims, and pointed out that steel rims are preferable in extreme off-road situations where damage to the rim is likely to occur. In these cases, an alloy rim is more likely to crack due to impact, whereas a steel rim can be bent or hammered back into shape in emergency situations.

This month, we’re talking about beadlock rims: what are they, how do they work, and who should fit them?

WHAT IS A BEADLOCK RIM?

Once again, if you’re driving extreme off-road trails where vehicle-, tyre- or rim damage is likley to occur, you may choose to deflate your tyres to extremely low levels.

However, in the case of a standard rim (steel or alloy), the bead area of the tyre is seated against the rim with the help of internal air pressure. If the pressure inside the tyre is deflated too low, the force necessary to seal the bead may not be enough, and the risk of de-beading the tyre is high.

If a tyre does de-bead (also known as ‘break its bead’), it will continue to leak air until the tyre…

• Is completely flat
• Runs off the rim entirely
• Sustains permanent friction damage to the bead/seal area

What’s more, a tyre that has broken its bead is a difficult thing to re-inflate, and may require an air volume that’s beyond the abilities of most 12V air compressors. Lastly, even if you do manage to pump enough air into the tyre for the bead area to re-seat, there’s a good chance that dirt and sand will get trapped under the seal and continue to leak air as a slow puncture.

In short, the more you deflate, the greater the chance of de-beading your tyres and having to endure all the hassles listed above. So what’s the solution?

ENTER: THE BEADLOCK RIM

In the case of beadlocks, the rim features a bolted outer ring that clamps the tyre’s bead area. Meaning, the tyre is no longer reliant on air pressure to seal the bead, but rather, it’s “locked” in place by the bolted ring. With the tyre now clamped down, there’s far less chance of the bead breaking under extremely low air pressures. This allows extreme off-roaders to deflate their tyres for better performance over loose, slippery, or wet terrain. 

On that note, let’s look at some of the pros and cons of fitting a beadlock rim…

PROS:

• Better off-road traction
• More comfort
• Less tread belt punctures
• Tyre moulds to the contours of the terrain
• Many people love the look of a beadlock rim
• The tyre should remain on the rim in the event of a high-speed blowout (Information credit: Allan Venter)
• Beadlocks may help to prevent sand and mud from forcing their way between the tyre and the rim (Information credit: Allan Venter)

CONS:

• Far more costly than a standard rim (sometimes double or triple the price)
• Difficult, costly, and time consuming to install
• Due to the additional work, some tyre dealers may refuse to fit a tyre to a beadlock rim
• Very hard to balance
• Extreme deflation will forfeit your tyres’ warranty
• Beadlocks are heavier than standard rims, leading to less fuel economy and potentially less engine performance
• Maintenance, you may have to re-torque the beadlock’s bolts several times a year
• Harder steering response from significantly aired-down tyres
• At extremely low air pressure, structural tyre damage is likely to occur
• Greater chance of sidewall tyre damage due to rock pinching

CONCLUSION

Although beadlocks certainly look the part, unless you’re an avid off-roader who frequently drives grade 5 trails and suffers regular de-beading problems, there’s little to no reason for fitting a beadlock rim. It’s also important to realise that any extreme tyre deflation will void your tyre’s warranty, regardless of what tyre make or brand you have.

If you like the look of a beadlock rim, but don’t want to deal with the maintenance issues that come with owning a set, you can also fit an imitation beadlock rim. TyreLife Solutions distributes a wide range of alloy rims, steel rims, imitation beadlock rims, and genuine beadlock rims. Follow the link for more information: www.tyrelife.co.za

Brought to you by TyreLife Solutions

The post What are beadlock rims and are they worth it? appeared first on 4WD Revolution.

If you’re in the market for a new set of rims, you may be contemplating the benefits of steel wheels versus alloys. Let’s look at the pros and cons of each.

ARE STEEL WHEELS BETTER?

PROS:

• Malleable and resistant to high-impact forces
• Easy to bend, but very hard to crack
• Strong centre
• Can be re-shaped / repaired on a trail or remote area
• Affordable
• Widely available, even in remote regions

CONS:

• Weak edges in terms of distortion and bending
• High heat-conductivity
• Prone to rust if scratched
• Limited sizes that are specific to off-road use and high-profile tyres
• Slightly heavier
• Harder to balance if distorted
• Limited design styles in terms of customising

ARE ALLOY WHEELS BETTER?

PROS:

• Are extremely rigid and resistant to mild impact forces
• Are hard to bend or distort
• Have strong edges
• Won’t rust if they have been scratched
• Are better suited to low- or medium-impact forces
• Are easier to balance
• Have a wide range of styles available
• Offer a wide range of sizes for most vehicle types
• Have low heat-conductivity

CONS:

• More likely to crack in a severe impact
• Are seldom available in remote regions
• Are difficult (and sometimes impossible) to repair
• Are more costly than steel wheels
• A crack in the bead area will allow air to leak from the tyre
• There is a greater risk of theft

So which is better: Steel or alloy rims?

We tend to think of steel rims as the stronger option, but in some cases, where potential impact forces are low or medium, alloy rims are less likely to distort, and are therefore less likely to cause other problems such as with balancing.

However, if the wheel is exposed to extreme impact forces (particularly if the tyre is flat or significantly deflated), alloy wheels are more likely to crack. Needless to say, a cracked alloy rim is almost impossible to fix on a trail and is likely to leak air. In most cases, the wheel will have to be scrapped.

In contrast, steel wheels are far more malleable, which means that they are easier to bend (especially on their edges), but are almost impossible to crack. In other words, most steel wheels can be knocked back into shape with a hammer in emergency situations, and it is very unlikely that a steel wheel will ever leave you stranded.

As far as other damages go, such as rock rash, etc., a steel wheel will obviously rust if badly scratched. However, in most cases, the corrosion is surface-bound and easy to brush off and repair. Of course, alloy wheels won’t rust if scratched, but because they tend to cost more, it’s often harder to face any damage to the rim. 

Typically speaking, steel wheels tend to weigh more than equally-sized alloy rims, but the differences are often marginal, and the impact on fuel consumption is far more likely to be affected by your tyre choice, particularly if the tyre’s carcass is a Light Truck variant, as opposed to a P-Metric alternative.

In many ways, debating ‘steel versus alloy’ is encapsulated in the Chinese proverb, “The green reed which bends in the wind, is stronger than the mighty oak which breaks in the storm.” So, the question of which is best depends on the storms (i.e. trails) you hope to chase.

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The post What’s better: steel or alloy wheels? appeared first on 4WD Revolution.

If your vehicle has recently picked up a slight vibration and some road noise, it could be an indication that your tyres need rotating. Other symptoms of an overdue tyre-service include:

1. Higher costs per kilometre 
2. Uneven tread wear
3. Increased road noise, and
4. Steering wheel vibrations

So, why do tyres wear unevenly?

First off, your front tyres generally carry more load than the rear, and because they also take sharper turns, the wear rate is different. However, your tyres also wear differently from left to right, and that’s because we typically take corners faster to the right when driving on the left-hand side of the road. And lastly, the road’s natural camber also causes uneven tyre wear.

Rotating your tyres helps to equalise these wear rates, which means longer tyre life, quieter road noise and a smoother ride. This is true for all tyres, but failure to follow a rotation schedule is particularly noticeable on all-terrain and mud-terrain tyres.

But how often should you rotate your tyres? And, which is just as important, in what sequence should you rotate them?

4WD REVOLUTION: “CLICK HERE FOR AN INSTANT QUOTE ON 4X4 TYRES“

Relying on your local tyre dealer to know this information is not always a good idea, as the rotation pattern is different for Front-Wheel Drive (FWD), Rear-Wheel Drive (RWD) and All-Wheel Drive (AWD) vehicles. Throw in the problem of incorporating a fifth tyre (the spare), and the subject becomes even more confusing.

As a general rule, you should first check the vehicle’s Owner’s Manual for the recommended tyre-rotation sequence. However, if you can’t find the relevant info, there are several ways to rotate your tyres. Here’s what you need to know for your vehicle type…

FORWARD CROSS (FWD vehicles)

The front tyres move straight back to the rear, and the rear tyres move to the opposite front position.

See Diagram A below.

REARWARD CROSS (RWD vehicles and part-time 4x4s)

The rear tyres move straight up to the front, and the front tyres move to the opposite rear position.

See Diagram C below.

X-PATTERN (FWD vehicles)

This is an alternative sequence to the forward-cross pattern. Here, the front tyres move to the opposite rear positions, and the rear tyres move to the opposite front positions.

FRONT TO BACK (Directional Tyres)

Due to their specific tread pattern, directional tyres are designed to move only in a single direction, which means that the tyres have to move from the front to the back, while remaining on the same side of the vehicle. In other words, the front right tyre moves to the back right, and the front left tyre moves to the back left.

5 TYRE PATTERN (AWD Vehicles and Full-Time 4x4s)

If your vehicle is equipped with a full-size spare, you may want to incorporate the fifth tyre into your rotation sequence to ensure even wear. This can be particularly important for AWD vehicles and full-time 4x4s, where a difference in tyre diameter could put unnecessary strain on the vehicle’s drivetrain.

In this case, move the left-rear tyre to the left-front position, and the right rear tyre to the right front position. The right front tyre goes to the left rear position, the spare tyre moves to the right rear position, and the left front tyre then becomes the spare.

See Diagram D below.

HOW OFTEN SHOULD YOU ROTATE YOUR TYRES?

Just as your vehicle has an annual maintenance plan, your tyres need regular maintenance to ensure optimum performance, tread-life, and comfort. Your vehicle’s service book should provide guidelines on how often your tyres need balancing, rotation and alignment.

Brought to you by TyreLife Solutions

The post How to rotate 4×4 tyres appeared first on 4WD Revolution.

In order to answer the above question you first need to know:

• How much power are you using on a daily basis, and…
• How much time do you have to replace it?

Naturally, your camping fridge uses different degrees of power throughout the day. This is because ambient temperatures can radically fluctuate between morning and night.

It also has a lot to do with opening and closing the fridge, which you’ll presumably do more often during the course of the day, than you would at night

However, typically speaking, most 12V camping fridges use between 30A/h and 40A/h over a 24-hour period.

Depending on daylight conditions, as well as your geographic location, most campsites have anywhere between 2- and 7-hours of usable solar input.

Considering an 85W panel produces approximately 5A per hour (in ideal conditions), you would need at least 7-hours to replenish the 35A you’ve removed.

That said, in order to account for non-ideal conditions such as dew and partly cloudy weather, it’s best to upsize the panel to a 120W or 150W unit. What’s more, upsizing your panel will help to produce enough energy to power additional camping accessories such as LED lighting, and/or a cellphone charger.

Of course, the above calculations are radically simplified in terms of fridge size, performance, operating conditions, and how often you’re reaching for “one last beer”.

That said, it’s not uncommon to find campers using panels that are up to 300W in size. However, bear in mind that your regulator would need to be rated to this capacity, and that such a panel would be impractically large in the case of a non-flexible unit.

FREQUENTLY ASKED QUESTIONS

1)   Does the quality of the panel make a big difference?

Yes, panel quality can significantly affect the performance and efficiency of your solar setup. Panels are typically divided into two main options: Monocrystalline and polycrystalline. Monocrystalline panels are generally more expensive and better performing due to their structure being made from one large crystal. This is in contrast to Polycrystalline panels which are made from lots of smaller crystals.

It also means that Monocrystalline panels produce more energy in relation to their size. 

2)   Does the quality of the regulator make a big difference?

This will depend on several factors, but generally speaking MPPT regulators are better performing and more costly than PWM regulators.

3)   Does my battery type make a big difference?

Yes, battery chemistry (and size) can play a significant roll in the performance of your solar setup.

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The post What size solar panel do you need for camping? appeared first on 4WD Revolution.

Winch cables don’t last forever, and when they do fail the results are often catastrophic and/or costly. This is why cable inspection and maintenance are vitally important.

While most winch cables (also known as ‘wire rope’) are lubricated during the manufacturing process, the factory-applied lube is only adequate for the initial storage of the cable, as well as the early stages of its service life.

Correct winch-cable lubrication is important for two reasons:

1. It reduces friction between the individual wire strands.
2. It provides protection against corrosion.

CORE IMPORTANCE

Typically speaking, winch cables fail at their core. This is because the inner portion of the cable is often poorly lubricated and prone to corrosion. To make matters worse: Core corrosion is difficult to see and monitor, which makes rust prevention that much more critical as there’s no way of knowing when the rope will fail!

On that note, there are two types of cable lubrication: External and internal. For the reasons mentioned above, it’s crucial that a high-quality penetrating oil is used when lubricating a winch cable. However, it should be noted that overly thin lubes (such as most multi-purpose oils) tend to dry out quickly and are not ideal for winch-cable maintenance.

In contrast, grease-like lubricants are generally too thick to adequately penetrate the cable’s core. They also have a tendency to gather dirt and lead to further maintenance issues. 

Most winch cables fail from the inside. This is due to incorrect lubrication that’s unable to penetrate the cable’s core. While the cable may look healthy on the outside, the inner core may be significantly weakened due to rust and corrosion. This is why it’s important to use a dedicated winch cable lubricant that deeply protects the cable from the inside out.

IDEAL WINCH CABLE LUBRICANT

The ideal winch cable lubricant should be thin in its application, but then have the ability to drive out moisture, protect against corrosion, and quickly solidify into a more adhesive state.

What’s more, the lubricant should be clear in colour. This makes it easier to inspect the cable in the future for potential fraying.

That said, the lifespan of your winch cable is directly proportional to the effectiveness of its maintenance, and if lubricated correctly, the service life of the cable should more than double.

Thankfully, CRC Industries’ boasts a ‘Chain & Wire Rope Lubricant’ that’s specifically formulated for winch cables. This special blend of synthetic lubricants, solvents and Molybdenum, are designed to keep hard-working chains and cables in peak operating condition.

CRC’s ‘Chain & Wire Rope Lubricant’ is clear in colour, deep penetrating, and because the formula is petroleum based, will help to clean the cable as the lube is applied.

What’s more, thanks to the product’s incredibly fast evaporation rate, the lube quickly thickens after application and deeply coats each wire strand with a non-drying protective film and lubricant.

APPLICATIONS INCLUDE…

• Winches
• Low speed conveyors
• Drive chains
• Hoists
• Rollers
• Garage doors
• Bushings
• Seals
• O-rings
• Come-alongs

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The post Why it’s important to lubricate your winch cable appeared first on 4WD Revolution.

Is it time to ditch your lead-acid battery for lithium-ion technology?

While some overland travellers have migrated away from lead-acid batteries in favour of Lithium Iron Phosphate (LiFePO4), others are not yet convinced of the economics.

Although it may be true that the higher costs of a LiFePO4 auxiliary battery make it harder to justify in a vehicle-based application (where the system is only used a few times a year), there are significant recharge benefits to switching to a LiFePO4 dual-battery setup.

Economics aside, the real question is: How much better performing is LiFePO4 when compared to lead-acid batteries?  And, does that performance justify the higher upfront costs?

BATTERY TESTS

Boasting a range of DC-DC chargers that are all lithium, AGM and wet-cell compatible, National Luna recently tested three battery options that are commonly used within the leisure market. We conducted these tests by discharging each battery type by 70Ah, and then recorded the recharge performance using our 25A and 40A DC-DC chargers.

As shown in the graphs below, the LiFePO4 battery features a longer ‘Bulk’ charging stage in relation to its shorter ‘Absorption’ stage. This is thanks to lithium having a better ‘Conversion Efficiency’, which means the LiFePO4 battery reaches its full capacity in a far shorter period.

In contrast, the recharge performance of the wet-cell and AGM batteries is hindered by a disproportionately short ‘Bulk’ stage, in comparison to a longer ‘Absorption’ stage.

What’s more, the extra 15 amps of the NLDC-40 help the LiFePO4 battery reach a full charge in less than 2-hours. Needless to say, a rapid recharge cycle is supremely practical in terms of driving times and how you plan your road trip.

PROS & CONS

Of course, only you can decide if the above data justifies a migration, but aside from the rate of recharge, there are several other pros and cons to consider.

LiFePO4 PROS:

• Charges faster
• Significantly lighter (important for portable systems)
• Can be deeply discharged without greatly affecting battery life
• Has a longer life span

LiFePO4 CONS:

• Heat sensitive
• Costly initial expense
• Requires a unique charging algorithm
• Cannot be charged directly from your vehicle’s alternator
• Can have a much lower current limit, making it unsuitable for high-current applications, i.e. winching and engine cranking

SUMMARY

With the above points in mind, it’s clear that the decision to adopt LiFePO4 technology has less to do with economics, and more to do with the convenience of having a fast-charging dual-battery system.

That said, it’s really a personal question of whether the performance benefits of a LiFePO4 battery are enough to overlook the initial costs of the newfangled technology.

However, it should also be noted that the integration of a solar panel will also greatly influence your decision, as well as your camping habits: Do you typically drive long distances between camps, do you move around a lot, or do you tend to stay in one campsite for a few days?

What’s more, not all DC-DC chargers support lithium technology, so make sure your DC- DC unit is lithium compatible before you make any changes to your dual-battery setup.

Brought to you by National Luna

The post Lithium-Ion vs lead-acid deep cycle dual-battery system appeared first on 4WD Revolution.

The 4×4 travel market has no shortage of hot debates and shootout tests. Whether it be vehicles in a comparison, or tyres, suspension, fridges, winches, or even camping pots for that matter, people want to know what works “best”.

However, there’s one subject that many overland travellers are generally keen to steer clear of, and that’s the topic of batteries and split-charging systems.

So why is the topic so controversial?

Well, it has a lot to do with varying vehicle types, alternators, preferred battery locations, power needs, and of course, different driving times / distances. There are so many variables to consider that it’s almost impossible to say: “This dual-battery system is better than that one”.

With this in mind, we laboratory tested various dual-battery kits, along with various battery types, to determine which setup performed “best”. However, rather than deliver a conclusive result, the tests highlighted just how complex the subject really is.

The following graphs highlight what we found in terms of when a solenoid system works best, and when a DC-DC system should be the preferred choice.

SOLENOID TEST

The above mentioned tests concluded that in certain instances, if your vehicle’s alternator output delivers a constant voltage of 13.9V or more, then a 20A to 25A DC-DC system will actually slow down the recharge process. In fact, above 13.9V, the solenoid system radically out performs (within the first few hours of driving) any 20A to 25A DC-DC charger on the market, regardless of what type of battery you use.  

As shown in the graph above, the solenoid system (blue line) rapidly outperforms a 25A DC-DC setup (red line) within the first 3-hours of driving. You’ll also notice that at this voltage (13.9V), the solenoid system doesn’t quite make it to full capacity (98% charged).

However, in saying that, it will also take the DC-DC system more than 5-hours (driving time) to fully recharge the battery.

This explains why so many dual-battery systems work well within the first year or so, but as time goes by, the system becomes less efficient. The reason for this is because the performance of the battery is declining with each partially recharged state. This is especially important for wet-cell batteries.

That said, it’s strongly recommended that an Intelligent Maintenance Charger be used (after your trip) no matter what type of system you use. The mistake many of us make is to believe that a few hours drive home will do a sufficient job at recharging the auxiliary battery, when in fact, the battery still needs a maintenance charge in order to reach a full (storage friendly) state.

DC-DC TEST

The graph below highlights the obvious advantage of a DC-DC setup once the alternator’s output is as low as 13.5V.

Although the solenoid switch is still outperforming the DC-DC system within the first 2-hours of driving, the bigger issue is that the solenoid noticeably fails to fully recharge the battery (even after 8-hours), and the best it can do is an 86% recharge state.

If you continue driving for more that 2-hours the DC-DC system starts to drastically outperform the solenoid switch.

To further complicate things, the tests showed that your chosen battery type (wet-cell, deep-cycle, AGM and lithium) played a fundamental role on how well the DC-DC system worked.

Put another way: If your DC-DC charger is unable to change its charging profile to suit certain auxiliary battery types, it could potentially ruin your battery.

What’s more, because DC-DC systems are heat sensitive, once engine-bay temperatures reach 50ºC+ (a very normal under-bonnet temperature), many DC-DC units shut down. Which is why it’s often best to install your auxiliary battery and DC-DC system in the boot of your vehicle – away from heat. Incidentally, solenoid switches don’t have the same problem.

SUMMARY

• If your vehicle’s alternator delivers a constant voltage output of 13.9V or more, a solenoid switch is the preferred choice.
• If your vehicle’s alternator delivers a constant voltage output that’s less than 13.9V, a DC-DC charger will do a better job at restoring the auxiliary battery’s (near) full capacity.
• No matter what dual-battery system you install, it’s advisable that an Intelligent Maintenance Charger be used to service the auxiliary battery and restore it to full capacity after each road trip.
•  Aside from the 13.9V threshold, the tests do highlight a growing need for DC-DC chargers within the modern-vehicle market and their increasing use of variable voltage alternators.
• Most high-end DC-DC systems include other functionalities such as solar compatibility and lithium-ion support. So if either of those features is important to you, then a good quality DC-DC system is the obvious solution.

Brought to you by National Luna

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