Do you need a lithium battery powered caravan?

There was no 12-volt battery in our first Jayco camper trailer. So we used a portable battery-powered lantern, went to sleep by fire and torchlight and rose with the sun and the birds.

No toilet, or hot water either, so a bucket at night and the local campground facilities were the only options.

Coffee? It came in a jar or at best in a percolator. Washing? It happened in a bucket. Dishwasher? I was it. Air conditioner? Open the windows. Heating? Turn on the gas jets, or go to bed.

Today, things are very different for the modern off-grid caravanner, where literally nothing in modern domestic appliances is off the table. Tomorrow, your off-road caravan may be hard to sell if it doesn’t have some degree of renewable power, whether it be solar technology, lithium batteries or the latest in 48-volt mild hybrid, all-electric power.

But if you’re about to order a new van, or purchase a late model second-hand, van, how important is it to spec it to suit tomorrow’s travellers?

Future-proofing your caravan

Optioning a

And as for taking the kids or grand-kids away to see Australia, forget it if you can’t recharge their mobile appliances.

With finance rates still low, powering up is relatively easy. Lithium batteries and 48-volt power systems are lighter, smaller, and can function well longer than traditional lead-acid AGM batteries. Eight to 10 years is the expectation, compared with less than half that for an AGM battery.

On the flip side, it’s probably a waste of your money upgrading a new entry-level on-road caravan to lithium, as AGM deep cycle batteries work perfectly well in caravans destined to spend most of their nights at the end of a 240-volt power lead. Lithium is unlikely to enhance such a van’s market appeal or value as much as its conversion cost. A similar rule applies to upgrading a used, on-road caravan.

But, if it’s a quality off-road caravan, like a Bushtracker, Kedron, Trakmaster, Evernew, Sunland, or Spinifex,  it may be a sound investment in its future re-sale value. A 10 year-old, well-maintained van of one of these brands still has probably up to 10 more good years left in it – plenty to offset the cost of upgrading its power system.

At the same time you might want to upgrade and fit other appliances to match the capability of its new off-grid power and to fit an ensuite, if it lacks one, to ensure it appeals to a greater range of future buyers.

It really depends on what you want to do and where you want to go with your caravan.

If you’re a bitumen/main roads traveller who enjoys the comfort, convenience and kid-friendly features of caravan parks, a lithium or 48-volt battery conversion is probably a waste of your money.

AGM and deep cycle batteries are not hugely expensive and are readily available from any automotive chain-store or automotive electrical supplier around Australia, so that’s what I would stick with.

On the other hand, if you want to explore the Outback, or enjoy the solitude of neighbour-less living, lithium, or all-electric power, is something to consider.

Most lithium batteries also come with around double the warranty of an equivalent AGM, so this is a good period over which to amortise your investment.

If you travel most days, your vehicle will pump sufficient power back into your conventional lead-acid battery, or batteries, but if you plan to prop with a rod by a babbling brook to enjoy nature and a bit of fishing, as well as deploying your various ‘comfort’ appliances, you will soon exhaust its capacity.

A cooked breakfast, a few pods of coffee, maybe a few minutes of 12v fan use to cool the van as the hot sun rises, will see you done for a while until you can hit the road again, or fire up a portable generator to re-charge.

Many people try to overcome this by filling their caravan roof with solar panels. This works as long as your van is in direct sunlight for most of the day, but as most people in hot weather seek shade, this soon limits your ability to recharge your batteries.

Solar panels recharge with light, not heat (they can even deliver some charge in full moonlight), but as we recently discovered in shady Adele’s Grove in Queensland’s Lawn Hill, heavy shade is a battery’s enemy. Our solution was a 160W portable solar panel that we had to keep moving to chase the sun, but it was no substitute for the 450 Watts of solar left shaded and under-utilised on our van’s roof.

Is lithium the answer?

Is lithium the ‘new’ caravan battery? At present, yes.

Those available to the RV market are LiFePO4 (lithium iron phosphate), a recent, more stable and therefore safer version of the original LiCoO2 (lithium cobalt oxide) batteries which are typically used in mobile phones, laptops and digital cameras.

LiFePO4 batteries might also be called lithium-ion, but technically lithium-ion (or ‘li-ion’) is the generic name for all lithium batteries.

There are many reasons why lithium batteries are becoming widely adopted, particularly by the off-road caravan industry:

Now the down-side. While lithium caravan battery systems are a lot more efficient and lightweight, they aren’t cheap, with costs often upwards of $5000, and in some cases well into five figures, depending on the brand and size.

Of course if you're ordering a new van you will be paying an upgrade cost over AGM, while if re-powering an existing AGM-equipped van you will probably have to recoup some of your costs on eBay or Gumtree.

But unless you’re buying a prestige off-road caravan, the extra cost may not be worthwhile.

Where they really come into their own is when you do a lot of off-roading or are reliant on solar power for weeks at a time. They’re light, so you can reduce weight considerably – at least 50 per cent – by jettisoning the old lead batteries you’ve been carrying to power your lifestyle when off the grid.

The savings on fuel costs probably won’t balance out, but it all counts and the efficiency, longer life-span and lighter weight make it a financially sound choice – if you use it.

For off-road caravaners who spend lots of time off the grid and for whom solar is a major charge source, two panels will keep the fridge going, the lights and water pump on and help keep the battery charged. A third panel will allow for more loads or help when you have partly overcast days.

However, when solar panels are installed on caravans, they are usually lying flat on the roof most of the time, which can reduce their output by more than a third.

With this much drop in output, extra panels are needed to make up the shortfall. If the van has enough space on the roof to install more solar, then install as much as you can fit and afford. If roof space is limited, then consider adding one or two portable solar kits that will allow you to capture more of the sun’s rays throughout the day.

If you happen to be camped up and have heavy overcast/raining conditions for two or three days, the solar is barely operating and the battery will drain down. Here you will have no choice but to plug in an alternate charging source. With an oversized solar setup, you have a good chance of producing a reasonable charge rate in these conditions without the need to plug in that alternate charge source.

The other advantage is when the sun does come out, the system will recover the batteries far quicker from the losses of the previous day/s.

For caravaners that rely on their solar as their No.1 charge source, you can never have too much solar. With the cost of solar panels these days compared to 10 years ago and the advancement in solar technology, a 600W system for example on an average off-road caravan should be able to sustain you in the field for days/weeks in the varying weather conditions we see in this great country of ours.

The next power frontier: 48 volt technology

An alternative to a straight lithium-ion replacement system is 48-volt mild hybrid technology.

This is a combination of things, with a 48-volt lithium-ion battery pack stored in the caravan that is fed by a starter generator which replaces the alternator and starter motor on the tow vehicle and transmits its output via a low-voltage DC/DC convertor.

Caravans fitted with 48-volt systems typically still retain their conventional 12-volt systems; this is referred to as a 48-volt mild-hybrid system.

In this scenario the 48-volt battery pack is used to store energy and supply it to the mild hybrid system. The mild-hybrid starter generator is connected via a belt to the crankshaft of the tow car’s internal combustion engine and can generate energy via recuperation of up to 12kW and 55Nm of torque generated at the mild-hybrid starter generator shaft. This energy is transferred back to the battery for use later.

So, the 48-volt battery can keep the electrics firing, while handling the load of an air-conditioner operating continuously.

Depending on the battery’s state of charge, the mild-hybrid starter generator also acts as a power boost for the internal combustion engine feeding in additional power when needed.

As today’s caravans are now true homes away from home, whether it be for a weekend, or for the ‘Big Lap’ this unlimited power supply is important.

Caravan operations with 48V-12V hybrid systems replenished by high performance solar usually layers over the top of the 12V system already installed, so new vans should have their warranty preserved with little disturbance.

The 240V power offers added automation for ease of use, with things like instant hot water, underfloor heating, ice makers, refrigeration, air-conditioning, heating and induction cooking able to be fitted at minimum size and weight.

The high alternator charging rate of up to 250A from a 4WD tow car further opens up the choice of all electric appliances.

If towing a caravan, then your 4WD becomes an electrical power plant. Just plug its 240V lead into the 48-volt system into your tow vehicle and enjoy up to 12 hours of constant air conditioning in the caravan while travelling. Then drive for a couple of hours the next day to replenish that energy for the night ahead.

A dual 12V/48V system uses a low-voltage, conventional lead-acid battery and adds a 48V lithium-ion battery to it with a separate 48V network.

With the system currently being installed by Gold Coast-based 48-volt specialists Safiery, the 48V mild-hybrid system comprises a lithium-ion storage battery, a Buck Boost DC/DC converter that integrates the 12V electrical system, controllers for the battery and hybrid powertrain, plus an electrically driven turbocharger.

The 48V electrical system doesn’t replace the car’s standard 12V electrical system –  instead, it’s connected to the 12V system via the DC/DC converter. That’s because accessories in conventional cars have been designed to run on a 12V system. The mild hybrid working at 48V battery only runs a portion of the vehicle’s electrical system.

The initial 48V systems are mostly being designed around the powertrain, which leaves the rest of the electrically driven components to continue to operate on a 12V electrical architecture, fed by a conventional lead-acid battery.

Future electric driven devices which need the power of 48V systems will include electric superchargers and electric anti-roll systems.

The 12V network will mostly likely continue to handle traditional loads like lighting, ignition, entertainment, audio systems, and electronic modules. On the other hand, the 48V network will support devices on the tow vehicle such as active chassis systems, air conditioning compressors, and regenerative braking.

The cost of installing a 48-volt system varies from caravan to caravan depending what is being replaced and retained, but a typical Safiery upgrade costs about $10,000-$15,000. Then add your home appliances!

This article was first published in October 2021.