Campervan Battery Guide: Sizing, Types & Installation (2025)

· 5 min read

Choosing the right leisure battery for your campervan is the single most important decision in your electrical build. Get it wrong and you'll run out of power halfway through the evening. Get it right and you'll have reliable, worry-free energy for years.

This guide covers everything: battery types, sizing calculations, installation, monitoring, and specific UK product recommendations. For the complete picture of how batteries fit into your overall system, see our campervan electrical system guide.

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Battery Types Compared

There are two practical options for campervans in 2025:

LiFePO4 (Lithium Iron Phosphate)

The gold standard for modern van builds. Key advantages:

  • 80–90% usable capacity (vs 50% for AGM)
  • 3,000–5,000 cycle life (vs 300–500 for AGM)
  • Half the weight — a 200Ah LiFePO4 weighs ~22kg vs ~55kg for equivalent AGM
  • Stable discharge voltage — maintains consistent 13V until nearly empty
  • Built-in BMS — protects against over-charge, over-discharge, and short circuit

The main drawback is higher upfront cost, though the cost-per-cycle is actually lower. For the full comparison, see LiFePO4 vs AGM batteries.

AGM (Absorbent Glass Mat)

Still viable for budget builds or weekend-only vans:

  • Cheaper upfront — £80–£120 for 100Ah
  • Simpler — no BMS to worry about
  • Only 50% usable — a 100Ah AGM really gives you 50Ah
  • Heavier — 28kg for 100Ah
  • Shorter lifespan — 300–500 cycles

How to Size Your Battery

Battery sizing follows a simple formula. For a detailed walkthrough, see what size leisure battery do I need.

Step 1: Calculate your daily energy consumption in Wh (use our power audit guide or calculator)

Step 2: Divide by usable depth of discharge:

  • LiFePO4: daily Wh ÷ 0.8
  • AGM: daily Wh ÷ 0.5

Step 3: Convert to Ah: result ÷ 12

Step 4: Add 20% buffer and round up to nearest available size

For most mid-range builds using 1,000–1,500 Wh per day, a 200Ah LiFePO4 battery is the sweet spot. For a detailed comparison of common sizes, see 100Ah vs 200Ah vs 300Ah.

Planning for induction cooking?

Induction hobs draw 1,500–2,000W and need a large battery bank to support them. See our dedicated guide: battery sizing for induction cooking.

Best Batteries for Campervans (UK)

For detailed product reviews, see our best lithium batteries for campervans and Victron vs Fogstar comparison.

Budget pick: Fogstar Drift 105Ah (£290) — excellent value, 4,000+ cycles, built-in 100A BMS

Mid-range pick: Fogstar Drift 230Ah (£530) — best Ah-per-pound ratio on the UK market

Premium pick: Victron Smart Lithium 200Ah (£1,150) — integrates with Victron ecosystem, remote monitoring via Cerbo GX

Installation

Placement

Where you mount your battery matters for safety and performance. See campervan battery placement for detailed guidance. Key rules:

  • Mount securely — batteries must not move in a crash
  • Allow ventilation (even LiFePO4 needs airflow for BMS cooling)
  • Keep away from heat sources
  • Make cable runs as short as possible

Wiring Batteries in Parallel

If you're using multiple batteries, they must be wired correctly. See how to wire batteries in parallel for the step-by-step process. Always use identical batteries of the same age and type.

Never mix battery types

Connecting different battery types (AGM + lithium) or different capacities in parallel causes dangerous imbalances. Always use identical batteries.

Cold Weather Considerations

LiFePO4 batteries cannot be charged below 0°C without damage. Most quality batteries have a built-in BMS that prevents this, but you should understand the limitations. See charging lithium batteries in cold weather and campervan electrics in winter.

Battery Monitoring

You can't manage what you can't measure. A battery monitor tracks every amp in and out and gives you an accurate state of charge percentage. See campervan battery monitor guide for why you need one.

The Victron SmartShunt (£60–£80) is the most popular choice. See our SmartShunt setup guide for installation instructions. For a comparison of all Bluetooth-enabled monitors, see Bluetooth battery monitoring comparison.

Battery Health & Maintenance

LiFePO4 batteries are largely maintenance-free, but it's good practice to periodically check your battery's health. See how to check your campervan battery health.

Wondering how long your battery will actually last in real-world use? See how long will my campervan battery last for data from actual van builds.

Should You Buy Second-Hand?

Used LiFePO4 batteries can be tempting at 40–60% of new price, but there are risks. See second-hand lithium batteries: worth the risk? for our honest assessment.

FAQ

What size leisure battery do I need for a campervan?

For weekend use with basic appliances (lights, fridge, USB charging), 100–150Ah is sufficient. For full-time van life with a laptop, diesel heater, and moderate usage, 200Ah LiFePO4 is the sweet spot. For heavy usage including induction cooking, you'll want 300Ah+. Use our free calculator for a precise recommendation.

How long does a campervan leisure battery last?

A quality LiFePO4 battery lasts 3,000–5,000 charge cycles, which translates to 8–15 years of typical campervan use. AGM batteries last 300–500 cycles, or roughly 2–4 years.

Can I use a car battery as a leisure battery?

No. Car batteries (starter batteries) are designed to deliver high current for a few seconds, not sustained discharge over hours. Using one as a leisure battery will kill it within weeks. Always use a proper deep-cycle leisure battery.