A 12V 100Ah lithium battery is the single most popular upgrade Australian caravanners make to their power system. It is also the upgrade most commonly mishandled. The mistakes are rarely catastrophic on day one. They are slow-burning errors. The wrong charger profile. An absorption voltage set for AGM. A parallel connection with an old lead-acid pack. A sealed cabin compartment with no ventilation. Each one chips away at a battery that should give you a decade of service.
This guide assumes you have already chosen lithium iron phosphate as the right chemistry. It walks through how to set up the standard VoltX 12V 100Ah LiFePO4 deep cycle pack, or one of its sister variants, in an Australian caravan or camper trailer.
The short version
Pick a LiFePO4 pack rated to AS/NZS IEC 62619, mount it in an externally vented compartment, and install a DC to DC charger between your tow vehicle’s alternator and the pack if your vehicle was Australian delivered after 2015. Set your solar regulator to 14.4V absorption and 13.5V float, and disable equalisation. For most weekend caravanners, the standard VoltX 12V 100Ah LiFePO4 pack is the right place to start.
Voltx 12V 100Ah Slim Lithium LiFePO4 Battery
Before You Start: Three Things That Decide Whether Your Install Will Work
Most installation failures we see at the Outbax support desk trace back to three pre-install mistakes.
The first is your existing 240V charger. Most factory-fitted caravan chargers are profiled for AGM. Connect a lithium pack to one, and you risk chronic overvoltage and warranty loss. Pull the documentation on your charger before the new pack arrives. If you cannot confirm a lithium profile, plan to replace it.
The second is your tow vehicle’s alternator. If it was Australian-delivered after 2015, it almost certainly runs a smart alternator that varies output to save fuel. A traditional VSR isolator cannot deliver a clean lithium charge profile from a smart alternator, and the pack will sit chronically undercharged. The fix is a DC to DC charger, such as the VoltX SRNE 12V 30A DC to DC MPPT.
The third is compartment placement. LiFePO4 cells do not vent hydrogen the way old lead-acid packs did, but they still need ventilation to manage heat. The Outbax position, in line with AS/NZS IEC 62619, is to install the battery in an externally vented compartment, not inside the cabin and not in the engine bay.
Gentrax 12V 300Ah LiFePO4 Battery
Tools and Parts You Need
A typical caravan setup needs a lithium pack, a DC to DC charger, an MPPT regulator for solar, and a 240V mains charger profiled for lithium. On the wiring side, you will need an ANL or MIDI fuse on the positive lead, Anderson plugs for clean disconnects, appropriately-rated cable and lugs, a hydraulic crimper, and a multimeter to verify before you energise the system. The VoltX Battery Box with dual USB and 12V cig socket gives you a ready-made housing if you would rather skip the enclosure fabrication.
Choosing the Right VoltX 100Ah For Your Setup
All five VoltX 100Ah variants share the same one hundred amp-hour capacity and the same built-in BMS protection. They differ in warranty, monitoring, and form factor.
The standard VoltX 12V 100Ah LiFePO4 carries a three-year warranty, a 60-day money-back guarantee, and one hundred per cent usable capacity at 1,200 watt-hours from a full charge. It is the default choice for the weekend caravanner. The Pro model extends the warranty to five years and is the upgrade path for full-time tourers. The VoltX 12V 100Ah Bluetooth Daly Lithium Battery adds an app-connected BMS reporting voltage, temperature, and state of charge in real-time. The Slim and Blade variants deliver the same capacity in a narrow form factor for under-seat or behind-seat installation, useful when the existing battery bay will not take a standard block.
Here’s what one of our customers said:
“Been using my VoltX 12V 200Ah LiFePO4 Basic Lithium Battery for over 6 months now and its been working like a dream. Its been super reliable and holds its charge really well. Great product”
VoltX 12V 100Ah Blade Lithium LiFePO4 Battery
Where to Mount the Battery
Mount the pack low and central where you can to keep your caravan’s weight distribution honest. Keep the location dry, accessible, and isolated from heat sources such as exhaust runs. The Outbax position, in line with AS/NZS IEC 62619, is that the cell sits in an externally vented compartment, not inside the cabin and not in an engine bay. If your existing battery bay is too shallow for a standard block, the Slim or Blade variant, like the VoltX 12V 100Ah Blade Lithium Battery, fits in roughly a third of the depth without losing capacity. Secure the pack with foam padding and adjustable straps. The cells must not shift under braking or off-road vibration.
Here’s what one of our customers said:
“Have installed 2 x these batteries under drawers in my LC300, running a 96L Fridge/Freezer. All good so far, thanks.”
How to Wire It Without Damaging the Pack
The order matters. Disconnect all power sources first: shore power, solar, and any existing 12V supply. Run the main positive lead from the battery’s positive terminal to a central distribution bus bar, with the ANL or MIDI fuse no further than 150mm from the battery terminal. From the bus bar, branch out to your DC to DC charger input, your accessory circuits, and your inverter feed if you have one. Use crimped lugs, not soldered joints, which crack under vibration. Torque terminal bolts to the manufacturer’s specification rather than by feel.
Verify with a multimeter before energising. A fully-charged LiFePO4 pack reads between 13.4V and 13.6V at rest. A fifty per cent state of charge reads around 13.1V to 13.2V. If your reading sits outside this band, recheck your connections before connecting any load.
VoltX SRNE 12V/24V 30A MPPT Solar Charge Controller
Charging Architecture: The Three Sources
A 12V 100Ah pack in a caravan typically has three charging sources, and each one needs its own configuration.
From the alternator: Install a DC to DC charger such as the VoltX SRNE 12V 30A DC to DC MPPT between the start battery and your auxiliary lithium pack. The charger boosts smart alternator output to a clean multi-stage lithium profile. A VSR isolator alone is not the right choice for lithium on a modern Australian tow vehicle.
From solar: Set your MPPT regulator to lithium absorption 14.4V, float 13.5V, and disable equalisation entirely. Equalisation cycles use voltages that damage LiFePO4 cells. A 200W panel, such as the VoltX 12V 200W Folding Solar Mat, produces roughly 1,000-watt hours over five peak sun hours, enough to refill most of a 100Ah pack on a clear summer day in southern states. Winter yield drops sharply.
From 240V mains: A lithium profile charger is essential. The VoltX SRNE 50A AC LiFePO4 Charger refills a 100Ah pack from twenty per cent to full in around two hours.
How Long a 100Ah Pack Will Actually Last
A fully-charged VoltX 12V 100Ah Battery delivers around 1,200-watt hours of real, usable energy. A 60-litre 12V compressor fridge drawing two to three amps on average runs for thirty to forty hours from a full pack, comfortably more than two days in mild conditions and slightly less in inland summer heat. Eight LED downlights drawing two amps combined will run for about fifty hours.
A typical weekend off-grid load runs from fifty to eighty amp-hours a day. Above eighty-amp hours daily, particularly when an inverter feeds a kettle or microwave, step up to a 200Ah or 300Ah pack from the caravan battery setup collection.
Adding a Second Pack Later
The standard VoltX 100Ah supports series and parallel connections of up to six packs. Before you connect any second pack, measure both batteries with a multimeter. They must read within 0.1V of each other. If the gap is larger, charge each pack individually until they match. Do not parallel-connect a lithium pack with an AGM. The voltage curves and internal resistances are different, and the lithium pack will end up doing all the work and ageing prematurely.
Storage and Australian Climate
The VoltX 12V 100Ah operates between -25°C and 65°C. For long-term storage, the ideal range is -10°C to 50°C at a state of charge between thirty and sixty per cent. In the inland Australian summer, parked caravan compartments routinely exceed thirty-five degrees. The pack will survive this, but cycle life is preserved by parking in shade and venting the compartment when stationary.
When to Call a Licensed Auto Electrician
Three triggers warrant a licensed installer rather than DIY: vehicle warranty implications on a current model tow vehicle, complex three-source charging architectures with high amperage inverters, and any prior history of electrical faults in the caravan. Documenting the install for your insurer is good practice regardless.
Warranty, Money-Back Guarantee, and What Voids Coverage
Every standard VoltX 12V 100Ah LiFePO4 pack ships with a three-year warranty against defects in materials and workmanship, in addition to your rights under Australian Consumer Law. Outbax also offers a sixty-day money-back guarantee on returns in original condition. Pro models are equipped with a five-year warranty.
Warranty does not cover damage from charging at the wrong profile, paralleling with non-LiFePO4 chemistry, exceeding the operating temperature range, mechanical damage, or third-party modification of the BMS. Outbax ships from a Sydney warehouse next business day, with three to seven business days delivery across Australia. Batteries cannot be sent to PO boxes or parcel lockers.
Ready to Set Up Your Caravan or Camper Trailer Power System?
Most weekend tourers start with the standard VoltX 12V 100Ah LiFePO4 deep cycle pack, which carries a three-year warranty, a sixty-day money-back guarantee, and ships next business day from our Sydney warehouse. If you have questions before you wire it in, the Outbax support team is local and reachable.
Visit Outbax today to view the full range of our outdoor gear and choose the LiFePO4 battery best fit for your next outdoor adventure.
