Caravan Battery Size Guide: How to Size a LiFePO4 Battery in Australia (2026)

 A caravan battery is a deep-cycle battery that stores power for running 12V appliances off-grid. For most caravan owners in Australia, you typically need a 200Ah 12V LiFePO4 battery, which covers a fridge, lights, water pump, fans and device charging for 2 to 3 days without any charging input. Use this formula to calculate your exact caravan battery size: (Daily Ah x Days of autonomy) divided by 0.8, then multiplied by 1.2.

Over 901,000 caravans and campervans were registered in Australia as of January 2024, an all-time record and a 27% increase since 2019 (Tourism Research Australia, 2025). With Australians taking 15.2 million caravan and camping trips in 2024 and spending $14 billion in the process, reliable off-grid power has never mattered more. Yet the most common complaint we hear at LiFePO4 OZ is simple: the battery went flat on night two.

That is not a product problem. It is a sizing problem. This guide fixes it permanently.

Need help sizing right now? Call us on 1300 375 257 or browse our caravan battery kits.

What Is Caravan Battery Sizing and Why Does It Matter?

Caravan battery sizing is the process of calculating the exact battery capacity your 12V system needs based on daily power consumption, days of autonomy, and depth of discharge.

Get it wrong on the low side and you are chasing powered sites, cutting trips short, or waking up to a warm fridge. Get it wrong on the high side and you are towing 80kg of unnecessary battery weight that eats into your payload and costs you money on every trip.

Three variables decide your correct caravan battery size:

1. Daily energy consumption — total amp-hours your appliances draw each day

2. Days of autonomy — how many consecutive days you need between charges

3. Depth of discharge (DoD) — the safe usable percentage of rated capacity

The critical point most caravan owners miss is that rated capacity and usable capacity are not the same number. A 200Ah AGM battery gives you roughly 100Ah of safe usable power. Draw past 50% state of charge and you accelerate wear, reduce cycle count, and shorten lifespan dramatically. A 200Ah LiFePO4 caravan battery delivers 160Ah of usable power at 80% DoD without the same degradation. That difference alone is why lithium has become the default choice for Australian caravan owners replacing AGM systems.

"I switched from a 2 x 120Ah AGM to a single 200Ah LiFePO4 kit from LiFePO4 OZ. Same usable power, half the weight, and I have not had a flat battery in 14 months of full-time travel." - Mark T., QLD

LiFePO4 vs AGM Caravan Battery: Full Comparison

Before running the numbers, understanding why LiFePO4 outperforms AGM in Australian conditions is worth two minutes of your time. Australian summers regularly push van interiors past 50 degrees Celsius. AGM batteries degrade measurably above 40 degrees. LiFePO4 chemistry remains thermally stable well above 60 degrees, which is why it dominates the Australian off-grid caravan market.

A note on figures: Appliance consumption figures and daily Ah benchmarks throughout this guide are typical industry averages based on common Australian caravan setups. Individual results will vary depending on your specific appliances, usage habits, ambient temperature, and system wiring. These figures are a reliable starting point for sizing calculations. For a precise measurement of your actual system, use a battery monitor such as a Victron BMV or SmartShunt once your setup is installed. Product specifications, cycle life ratings, and warranty terms refer specifically to LiFePO4 OZ battery products. 

The cost per cycle comparison tells the real story. A quality 200Ah LiFePO4 kit from LiFePO4 OZ costs more upfront but delivers 5,000+ cycles versus 600 for AGM. Over 10 years of caravan use, the LiFePO4 option costs significantly less per amp-hour delivered, while saving you two to three battery replacements.

The weight difference is the other factor most people underestimate. Running 300Ah of AGM means carrying roughly 85kg in batteries. The equivalent LiFePO4 setup weighs around 38kg. That is nearly 50kg back in your tow capacity for a loaded six-week Kimberley trip.

Ready to upgrade? Explore our LiFePO4 caravan battery kits from 100Ah to 310Ah, pre-matched with smart BMS and shipped fast from Yatala, QLD.

Australian Standard You Must Comply With

Under AS/NZS 3001.2:2022, effective November 2023, all lithium batteries installed in Australian caravans must:

• Comply with AS IEC 62619 (international safety standard for lithium battery packs)

• Include a Battery Management System monitoring voltage, current and temperature

• Be installed in a sealed, vented compartment when located inside the habitable area

This applies to new builds and major upgrades including replacing AGM with lithium. Non-compliance can void insurance and affect registration. The standard is enforceable across all Australian states and territories through electrical safety regulations. (Source: Caravan Industry Association of Australia) 

Before buying any LiFePO4 caravan battery, ask the supplier one question: "Can you provide the IEC 62619 test certificate for the full battery pack?" Certified cells alone do not satisfy the standard. The BMS and complete pack must be tested together.

Every LiFePO4 OZ kit ships with a smart BMS that meets this requirement. If you are building from individual LiFePO4 cells, a certified Battery Management System is the most important component in the entire build.

How to Calculate Your Caravan Battery Size: Step-by-Step

This is the same process the LiFePO4 OZ technical team uses when sizing systems for customers. It takes 20 minutes done properly and eliminates guesswork permanently.

Step 1: List Every Appliance You Use Off-Grid

Walk through your van and write down every device you use when disconnected from mains power. Include standby draws. They add up.

Common loads: 12V compressor fridge, LED lights, water pump, roof vent fan, diesel heater, TV, phones and laptops, inverter loads such as kettle, induction cooktop, toaster or coffee machine, CPAP machine, Starlink, and any monitoring screens.

Step 2: Find the Power Draw for Each Device

Check the label for watts (W) or amps (A). Convert watts to amps using:

Amps = Watts divided by Volts

On a 12V system: a 60W fridge draws 5A. A 1,800W induction cooktop draws 150A. A 2,400W kettle draws 200A. Never skip inverter loads. They are where most systems get undersized.

Step 3: Calculate Daily Amp-Hours Per Appliance

Daily Ah = Amps x Hours of use per day

A fridge drawing 5A cycling 50% of the time uses about 60Ah per day. An LED light at 0.5A used for 4 hours uses 2Ah.

Step 4: Total Your Daily Consumption

Add every appliance to get your total daily Ah load. This is your baseline for everything else.

Step 5: Apply the Caravan Battery Sizing Formula

Required Battery Ah = (Daily Ah x Days of Autonomy) divided by DoD, multiplied by 1.2

For LiFePO4: DoD = 0.8. For AGM: DoD = 0.5. The 1.2 multiplier adds the 20% safety buffer that accounts for inverter inefficiency, parasitic loads, and the appliances you underestimated.

Caravan Battery Sizing Formula: Worked Examples

Example 1: Typical Touring Couple (120Ah/day, 2 days autonomy, LiFePO4)

Recommendation: 2 x 200Ah LiFePO4 (400Ah total). Comfortably future-proofed.

Example 2: Weekend Warrior (70Ah/day, 1.5 days autonomy, LiFePO4)

Recommendation: Single 200Ah LiFePO4. The extra headroom handles cloudy days without drama.

Typical Daily Power Consumption: Real Australian Caravan Loads

These figures are typical industry averages. Your specific appliances will vary. Measure your own system with a battery monitor once it is installed.

A standard comfortable setup including fridge, lights, fan, water pump, TV and device charging runs 80 to 110Ah per day. Add induction cooking or aircon and you can exceed 200Ah per day without much effort. That is where undersized systems fall apart on night two.

Is 200Ah Enough for a Caravan? 100Ah vs 200Ah vs 300Ah Compared

This is the most searched caravan battery question in Australia. The honest answer depends entirely on how you travel, not just what appliances you carry.

100Ah suits weekenders running basic 12V loads with at least 200W of solar. Two nights without sun or any inverter load will push you to the limit.

200Ah is right for roughly 80% of Australian caravan owners. Fridge, lights, fans, water, charging and modest TV use for 2 to 3 days without charging. Pair with 300W solar and a DC-DC charger and you can free camp indefinitely.

300Ah or more is the right choice if you regularly cook by induction, run aircon off-grid, travel full-time, or camp more than 4 consecutive nights without charge.

"We upgraded from 2 x 100Ah AGM to a 300Ah LiFePO4 kit. Now running full-time with induction cooking and a 90L fridge. Have not been to a powered site in 6 months." - Sandra and Pete, NSW

Browse our full range of caravan battery kits in 100Ah, 200Ah, 280Ah and 310Ah configurations.

How to Charge a LiFePO4 Caravan Battery: 3 Methods

Understanding your charging sources directly affects how much battery capacity you actually need. A well-charged system effectively extends your usable battery bank.

1. Solar via MPPT Charge Controller

The most popular method for Australian caravan owners and the most cost-effective over time. Solar panels feed through an MPPT solar charge controller into the battery. In good Australian conditions, 400W of panels delivers roughly 1.6kWh per day. Your controller must be set to a lithium charging profile. An AGM-profile controller undercharges LiFePO4 and shortens its lifespan. Most caravanners see full state of charge restored by mid-afternoon with 400W in summer conditions.

2. Alternator via DC-DC Charger

When you drive, your tow vehicle charges the caravan battery through a DC-DC charger. This is non-negotiable on modern vehicles with smart alternators, which vary output voltage to save fuel. A direct connection or old-style isolator relay does not charge LiFePO4 correctly and can trigger BMS protection. A quality 40A DC-DC charger typically delivers 30 to 40Ah for every hour of driving, meaning a 3-hour drive between camps makes a meaningful contribution to your state of charge.

3. Shore Power via Lithium-Compatible Mains Charger

At powered caravan park sites, a lithium-compatible mains charger recharges the battery overnight. Standard AGM chargers deliver the wrong charge profile for LiFePO4 and cause chronic undercharging and BMS trips over time. This is one of the most common issues in DIY AGM-to-lithium upgrades.

Most well-designed systems use all three sources automatically. The battery is always being topped up from whatever source is available, which is why a properly wired system rarely runs flat even with a modest 200Ah bank.

Common Mistakes When Sizing a Caravan Battery

These mistakes account for the majority of undersized system complaints we see at LiFePO4 OZ.

1. Ignoring inverter loads completely. Five minutes of a 2,400W kettle draws more amp-hours than your fridge uses overnight. A 30-minute induction cook session can draw 75Ah. Budget for every inverter load or the system will fail you at dinner time.

2. Forgetting standby drain. Inverters left on, stereos in standby, and monitoring screens collectively pull 0.5 to 1A continuously. That is 12 to 24Ah per day you never planned for.

3. Thinking in AGM percentages. With LiFePO4 at 80% usable depth of discharge, the numbers are fundamentally different. You do not need to double the bank when switching from AGM.

4. Not building autonomy for consecutive cloudy days. A week of overcast weather in Queensland or a grey fortnight in Tassie wipes out your solar income completely. Build 2 to 3 days of autonomy into your sizing so weather does not dictate your itinerary.

5. Skipping the 20% safety buffer. Real-world consumption always beats the spreadsheet. The buffer covers the parasitic loads, the appliances you use more than expected, and the inefficiency of your inverter under load.

6. Mismatching the BMS to the peak load. A Battery Management System underrated for your inverter load will trip under stress at peak demand. This is one of the most common reasons early lithium system failures happen.

7. Keeping the old AGM charger. Single most common mistake in DIY upgrades. An AGM charger delivers the wrong voltage profile for LiFePO4, causes chronic undercharging, triggers unnecessary BMS disconnections, and shortens cell life faster than heavy daily cycling ever would. A matched lithium charger is not an optional extra.

Real Australian Caravan Scenarios: Which One Are You?

The Weekend Warrior

Old 18-foot van. School holidays and long weekends. Mix of powered and free camps across regional NSW and VIC.

Daily loads: 12V fridge, LED lights, water pump, phone charging, TV. Daily Ah: ~70Ah. Autonomy: 1 to 2 nights. Recommended setup: Single 100 to 120Ah LiFePO4 + 200W solar + DC-DC charger. Why it works: One lithium replaces one AGM with double the usable capacity at half the weight. Simplest upgrade available.

The Touring Couple

Six to eight weeks on the road. Retired or long-service leave. Mix of free camps and powered sites across Queensland and the NT.

Daily loads: Large 12V fridge, lights, fans, water, devices, TV, coffee machine via inverter. Daily Ah: ~120Ah. Autonomy: 2 to 3 nights. Recommended setup: 200Ah LiFePO4 + 400W solar + 40A DC-DC charger + lithium mains charger. Why it works: 200Ah is the genuine sweet spot. Enough headroom for overcast stretches without overpaying for idle capacity.

The Full-Time Family

Four people on the road in a 24-foot van. Induction cooking, washing machine, multiple devices, and aircon when it hits 42 degrees in the Pilbara.

Daily loads: Full-size fridge and freezer, induction cooktop, kids' devices, aircon when needed. Daily Ah: 250 to 350Ah. Autonomy: 3 to 4 nights. Recommended setup: 2 x 200Ah LiFePO4 (400Ah total) or a 300Ah kit, plus 600 to 800W solar, 50A DC-DC charger and 3,000W pure sine wave inverter. Why it works: See our complete off-grid kits for pre-matched systems at this scale. Many full-timers also move to 24V to reduce cable losses and run a more efficient inverter.

The Remote Worker

Working from the van with Starlink, dual monitors and all-day laptop use. Power is a business-critical requirement.

Daily loads: Fridge, 8 to 10 hours of work equipment, Starlink, lighting. Daily Ah: ~150Ah. Autonomy: 2 to 3 nights minimum. Recommended setup: 200 to 300Ah LiFePO4 + 400 to 600W solar + DC-DC charger. Why it works: Size up, not down. A flat battery on a Tuesday morning costs more than the extra capacity does.

Have a different setup? Call our team on 1300 375 257 and we will work through your appliance list and give you a specific recommendation at no cost.

When to Upgrade Your Caravan Battery System

Caravan and RV registrations in Australia grew 27% between 2019 and 2024 to over 901,000 registered vehicles (Tourism Research Australia, 2025). As caravans get bigger and Australians travel longer, existing battery systems that were adequate three years ago are now falling short.

If any of the following sound familiar, you are already overdue for an upgrade:

• AGM batteries are 4 or more years old and will not hold charge past midnight

• You are seeking out powered sites you would rather skip

• The 12V fridge struggles to last 24 hours without a drive

• You have added Starlink, CPAP, induction, or aircon and the system cannot cope

• Battery weight is eating into your tow payload

• The inverter cuts out under load

If you have shortened a trip or skipped a free camp because of power, your system is undersized. A LiFePO4 upgrade through LiFePO4 OZ typically costs less than one year of powered-site fees for full-time travellers, while eliminating the need for them permanently.

Quick Caravan Battery Size Reference

LiFePO4 OZ: Why Australian Caravan Owners Choose Us

Queensland-owned and operating from Yatala, QLD. We size and supply complete battery systems, not just components.

Every kit uses Grade A EVE auto-grade cells with a 5-year manufacturer warranty. The same cell grade used in automotive-grade production runs. Not recycled cells, not solar-grade cells in automotive packaging.

Every kit includes a smart BMS rated for Australian peak loads, summer heat and the sustained daily cycling that real caravan use demands. Our BMS range covers 12V through 48V configurations.

We stock complete caravan battery kits from 100Ah to 310Ah, Grade A LiFePO4 cells for DIY builds, DC-DC chargers, lithium-profile mains chargers, and complete off-grid kits with battery, inverter and solar pre-matched in one package.

Fast road freight, Australia-wide from Yatala, QLD.

Key Takeaways

• Caravan battery sizing formula: (Daily Ah x Days autonomy) divided by 0.8, multiplied by 1.2

• 200Ah LiFePO4 is the right caravan battery size for most Australian owners

• LiFePO4 provides 80% usable capacity versus 50% for AGM at roughly half the weight

• Australian standard AS/NZS 3001.2:2022 requires AS IEC 62619 compliance and a certified BMS

• Always pair the battery with a quality BMS, lithium mains charger and DC-DC charger

• Over 901,000 caravans are registered in Australia. Most are still running undersized AGM systems

• Grade A cells with a proper BMS last 8 to 15 years. Size it right once and leave it alone

Sort Your Caravan Battery Size the Right Way

Australia had over 901,000 registered caravans as of January 2024, with registrations still climbing. If you are part of that growing community and your current battery setup is not keeping up, the fix is simpler than you think.

Browse caravan battery kits — 12V LiFePO4 systems with Grade A EVE cells, smart BMS and Australia-wide road freight from Yatala, QLD.

See complete off-grid kits — battery, inverter and solar pre-matched in one package, ready to order.

Call us on 1300 375 257. No automated systems. A real person who knows the product will work through your appliance list and tell you exactly what your setup needs — not the most expensive option.

LiFePO4 OZ. Queensland-owned. Powering the way Australians travel.

Frequently Asked Questions 

1.What size battery do I need for a caravan?

A caravan battery powers 12V appliances off-grid. For most Australians, a 200Ah 12V LiFePO4 covers 2 to 3 days. Weekenders need 100Ah. Full-timers need 300Ah or more. Formula: (Daily Ah x Days autonomy) divided by 0.8, multiplied by 1.2.

2. Is 200Ah enough for a caravan?

For most caravan owners in Australia, yes. It handles everyday loads for 2 to 3 days without charging. You need more only if you cook by induction, run aircon, or live in the van full-time.

3. What size lithium battery for caravan in Australia?

200Ah 12V LiFePO4 is the Australian standard recommendation. Handles Aussie heat, delivers 80% usable capacity versus 50% for AGM, weighs half as much for the same practical output.

4. How long will a 200Ah LiFePO4 battery last in a caravan?

2 to 3 days without solar input. With 300W or more of solar, effectively indefinite. Battery is rated for 3,000 to 6,000 plus cycles — that is 8 to 15 years of normal caravan use.

5. Can I replace my AGM with LiFePO4?

Yes, direct drop-in in most caravans. Same footprint, half the weight, double the usable capacity. You need a lithium charger and DC-DC charger. Most people upgrade as a complete kit.

6. Does my caravan LiFePO4 battery need to meet Australian standards?

Yes. AS/NZS 3001.2:2022 (November 2023) requires compliance with AS IEC 62619 and a BMS. Installed in sealed, vented compartment inside the van. Ask your supplier for the IEC 62619 test certificate.

7. What solar do I need with a 200Ah lithium caravan battery?

At least 300W for short trips. 400 to 600W for extended travel. In good Australian conditions, 400W delivers roughly 1.6kWh per day. Use an MPPT controller on a lithium profile.

8. Do I need a BMS with a LiFePO4 caravan battery?

Yes, mandatory under AS/NZS 3001.2:2022. Protects against overcharge, over-discharge, short circuits and overheating. All LiFePO4 OZ kits include a smart BMS. Never skip it when building from cells.