How I’d Build a Touring 12V System: What Matters, What Doesn’t & Where I’d Spend the Money

A touring power system can get complicated very quickly because there is always another battery, charger, panel, inverter or switch panel somebody will tell you that you need.

I look at it differently. Before buying anything, I want to know one thing: what are you actually trying to run, and how long do you need to run it for?

If your setup only needs to keep a fridge cold, charge phones and run camp lights for a weekend, you do not need the same system as somebody running a coffee machine, Starlink, induction cooking and a big dual-zone fridge hundreds of kilometres from the nearest town.

My quick verdict

Those capacities are starting points, not rules. Your actual loads and recharge opportunities matter more than the number printed on the battery.

The system flow I use

I think about touring power in this order:

1. Loads — fridge, lights, phones, cameras, pumps, Starlink, inverter loads.
2. Storage — how much usable battery capacity you actually need.
3. Charge while driving — normally the backbone of a touring system.
4. Solar — to replace what you use while the vehicle is parked.
5. Distribution and protection — fuses, cable size, connections and isolation.
6. Monitoring — knowing what is really happening instead of guessing.
7. Recovery — because a system that leaves you stranded was never a good system.

1. Start with the loads, not the battery

The fridge is usually the obvious load, but it is rarely the only one. Phones, camp lighting, pumps, cameras, radios and accessories add up. Add an inverter and suddenly kettles, coffee machines, laptops or induction appliances can become the biggest loads in the vehicle.

This is why I do not like the question, “What size battery should I buy?” without knowing what is connected to it.

A bigger battery only gives you a bigger bucket. If you cannot refill the bucket properly, you have just bought yourself a heavier flat battery.

2. Lithium makes sense for a lot of touring builds — but don’t buy capacity you can’t recharge

For a straightforward weekend setup, a 100Ah-class lithium battery can be plenty if the loads are sensible and the fridge is efficient. For a family setup, longer stays or heavier electrical use, 150–200Ah or more can make sense.

But I would rather see a well-designed 100Ah system with dependable charging than a 300Ah battery bank being fed through an undersized charger and poor wiring.

The battery, charger and wiring need to be designed as one system.

3. DC-DC charging is where I would spend money early

If the vehicle is moving most days, your alternator is one of the most reliable energy sources you have. A correctly sized DC-DC charger allows the auxiliary battery to be charged properly while protecting the starting system and giving lithium batteries the charging profile they need.

For lighter builds I would usually start looking in the 20–30A class. For larger touring systems, 40–50A or more can make sense — assuming the battery, alternator, cable sizing and installation support it.

I would not choose the charger purely because a bigger amp number looks better. The whole system has to be capable of using it safely.

4. Solar is brilliant — once you understand what it is replacing

Solar is not magic free power. It is simply another charging source.

If your fridge and accessories use roughly the same amount of energy each day as your solar can put back in, you can stay parked far longer without starting the vehicle. That is where solar becomes genuinely useful.

For weekend touring, a modest portable or fixed panel may be enough. For longer off-grid travel, larger fixed capacity plus the option to plug in a portable panel gives you more flexibility when the vehicle is parked in shade.

And I always design around poor conditions, not a perfect summer day with the panel pointed straight at the sun.

5. Monitoring: know the difference between battery health and state of charge

This is an area where people get caught out.

The Oricom BSM888X Battery Sense Monitor is a useful little tool for watching the health of the vehicle’s 12V/24V starting battery and checking the cranking/charging system. I like that for a touring vehicle because starting-battery problems are far better found in the driveway than at camp.

But I would not use that as a replacement for a proper shunt-based monitor on a serious auxiliary battery bank. Voltage alone does not tell you the complete story with lithium. For a larger house system I want to see actual current flow, energy used and remaining capacity.

6. Mains charging is boring right up until you need it

A good mains charger is one of those things that does not get much attention in a flashy 4WD build, but I reckon it is worth having.

The Oricom BC210 12/24V 20A Charger and Maintainer fits nicely into that role. It gives you a proper way to charge and maintain batteries at home rather than assuming the vehicle or solar will always sort everything out.

If a touring vehicle sits for periods between trips, this is exactly the kind of gear I would rather own than discover a weak starting battery the morning we are meant to leave.

7. Recovery: I want a jump starter that is accessible, charged and separate

I would carry a jump starter even in a vehicle with a beautifully built dual-battery system. They solve a different problem.

The Oricom JSP1200 IP66 Lithium Jump Starter + Power Bank is the one in the current AEC range that makes sense to me for touring because it is compact, weather resistant and easy to keep separate from the rest of the electrical system.

The key word is accessible. A jump starter buried under six tubs, the fridge slide and half the campsite is not much use when you actually need it.

Three systems I’d build differently

Weekend / casual touring

• 100Ah-class lithium auxiliary battery
• 20–30A-class DC-DC charging
• 150–200W-class solar depending on parking habits
• Fridge, lights and USB charging
• No large inverter unless there is a genuine 240V load that justifies it
• Starting-battery monitoring and a jump starter

This is the setup I think a lot of people actually need. Keep it simple, make the wiring good and leave room to expand later.

Regular touring / family setup

• 100–200Ah-class lithium capacity
• Higher-output DC-DC charging where the vehicle and battery support it
• 200–300W or more of useful solar
• Proper auxiliary battery shunt monitoring
• Quality fused distribution
• Inverter sized around actual appliances, not bragging rights
• Mains charger at home
• Independent jump starter

This is where I would spend more on packaging. The difference between a nice electrical build and an annoying one is often how easy it is to reach the fuse, isolate a circuit, remove the fridge or diagnose a problem.

Remote / serious off-grid touring

• Enough battery capacity to cover realistic poor-weather days
• Strong alternator charging and meaningful solar recharge
• Redundant charging options where practical
• Proper shunt monitoring
• Spare fuses, connectors and critical leads
• Jump starter kept separate from the auxiliary system
• Clean, labelled and serviceable electrical installation

Remote touring changes the question from “how many gadgets can I run?” to “what happens when something stops working?”

What I like spending money on

• Good batteries from companies that will actually support them.
• A DC-DC charger sized correctly for the system.
• Proper cable, terminations, fusing and installation.
• A real battery monitor on larger lithium systems.
• Enough solar to make stationary camping practical.
• Recovery gear that is independent of the system it may need to rescue.

What I’d think twice about

• Huge inverters: if you only use a 240V appliance twice a year, question whether redesigning the vehicle around it is worth it.
• Battery capacity for the sake of it: you still have to charge it.
• Cheap high-current wiring: this is not where I would chase the lowest price.
• Ten cigarette sockets: I would rather use proper connections and distribution for equipment that matters.
• Building everything at once: leave space and cable capacity for future expansion rather than guessing every future accessory.

My final pick

If I were building a normal dual-cab or wagon for the way most of us actually tour, I would start with the fridge and genuine daily loads, build a sensible lithium system around those loads, give it enough DC-DC charging to recover properly while driving, add useful solar, monitor it properly and keep the starting-battery recovery system separate.

I would spend the money on reliability, installation and charging before capacity and gadgets.

That will not make the sexiest spec sheet in the car park. It will make a much better touring vehicle.

Explore AEC Battery & Power or read our EvaKool Touring Fridge Guide to work out the main load your system may need to support.

High-current 12V and any 240V electrical work should be designed and installed appropriately for the vehicle, equipment and applicable Australian requirements. When in doubt, use a qualified installer.