Choosing between lithium (LiFePO4) and lead-acid batteriesis one of the biggest decisions in your campervan electrical system. Lead-acid costs less upfront, but lithium delivers 2x the usable power at half the weight and lasts 10x longer.
After installing hundreds of both types, we're now lithium-only for new builds. This guide breaks down every aspect so you can make an informed decision for your budget and usage.
Quick Answer
For 95% of campervans, lithium is the better choice. Yes, it costs 3-4x more initially, but you get double the usable capacity, half the weight, and it lasts 10x longer. Over the battery's lifetime, lithium is significantly cheaper per Wh delivered.
Head-to-Head Comparison
Usable Capacity
Lithium (LiFePO4)
100% usable capacity
100Ah battery = 1200Wh usable power
Lead-Acid / AGM
50% usable capacity
100Ah battery = 600Wh usable power
Why it matters: Lead-acid batteries suffer severe voltage drop below 50% charge. Lithium delivers full capacity without voltage sag.
Weight
Lithium (LiFePO4)
13-15kg for 100Ah
50-70% lighter than lead-acid
Lead-Acid / AGM
30-35kg for 100Ah
Heavy and difficult to move
Why it matters: Lithium's light weight improves fuel economy, payload capacity, and makes installation much easier.
Lifespan
Lithium (LiFePO4)
3000-5000 cycles
10-15 years typical lifespan
Lead-Acid / AGM
300-500 cycles
2-4 years typical lifespan
Why it matters: Lithium batteries last 10x longer. Over time, they're significantly cheaper per Wh delivered.
Charge Speed
Lithium (LiFePO4)
1C rate (100Ah in 1 hour)
Accepts high charge current
Lead-Acid / AGM
0.2C rate (100Ah in 5 hours)
Slow charging required
Why it matters: Lithium charges 5x faster, crucial for short solar windows and drive time charging.
Maintenance
Lithium (LiFePO4)
Zero maintenance
Sealed, no water topping up
Lead-Acid / AGM
Regular maintenance
Check water levels, clean terminals
Why it matters: Lithium is completely maintenance-free. Lead-acid requires regular checks and terminal cleaning.
Temperature Performance
Lithium (LiFePO4)
Excellent -20°C to 50°C
Minimal capacity loss in cold
Lead-Acid / AGM
Poor below 0°C
Loses 50% capacity in winter
Why it matters: Lithium performs well in cold weather. Lead-acid loses significant capacity when it gets cold.
Initial Cost
Lithium (LiFePO4)
£400-600 for 100Ah
Higher upfront investment
Lead-Acid / AGM
£100-200 for 100Ah
Cheaper to buy initially
Why it matters: Lead-acid wins on initial cost, but you'll replace it 5-10x more often than lithium.
The Real Cost Over Time
Everyone focuses on the initial price, but that's misleading. Here's what you'll actually spend over 10 years:
Lithium (LiFePO4)
Usable energy: 2400Wh × 3000 cycles = 7,200,000Wh
Cost per kWh delivered: £0.125
Lead-Acid (AGM)
Usable energy: 2400Wh × 500 cycles = 1,200,000Wh
Cost per kWh delivered: £1.42
The Math is Clear
Lithium costs £900 upfront but £0.125 per kWh delivered.
Lead-acid costs £400 upfront but £1.42 per kWh delivered - over 11x more expensive per unit of energy when you factor in replacements and reduced capacity.
When Lead-Acid Might Make Sense
We're not saying lead-acid is always wrong. There are specific scenarios where it might be appropriate:
✓ Very Limited Budget
If you literally cannot afford £400-600 upfront for lithium, a £150 lead-acid AGM will get you going. Just understand you'll need to replace it in 2-3 years and it only gives 50% usable capacity.
✓ Rarely Used Van
If you only use the van 5-10 nights per year, a lead-acid battery might outlast your ownership. The lifespan advantage of lithium doesn't matter if you're not cycling it frequently.
✓ Selling Van Soon
Planning to sell within 1-2 years? Lead-acid gets you through that period cheaply, and the next owner might not value the lithium upgrade enough to justify your investment.
Our recommendation: If you're building a proper campervan conversion that you'll use regularly, save up the extra £500 for lithium. It's worth it. If money is genuinely tight, get a single 100Ah lithium battery rather than 2x 100Ah lead-acid - you'll get the same usable power and can add more lithium later.
Charging System Requirements
Lithium Charging
- Requires DC-DC charger (not split charge relay)
- Charge voltage: 14.4V bulk, 13.5V float
- No equalization stage needed
- Solar MPPT with lithium profile
- Don't charge below 0°C without heater
Modern equipment has lithium profiles built-in
Lead-Acid Charging
- •Can use old split charge relay (not recommended)
- •Charge voltage: 14.4-14.8V bulk, 13.6V float
- •Monthly equalization charge at 15.5V
- •Any solar controller works
- •Slow charge rates (max 0.2C)
Requires more complex charging profile
Important: If you switch from lead-acid to lithium, you MUST update your DC-DC charger and solar controller settings to lithium profiles. Using lead-acid charging voltages will damage lithium batteries.
Expert Battery Installation
We'll help you choose between lithium and lead-acid based on your budget, usage, and plans. Our installations include correctly sized cables, appropriate fusing, proper charge settings, and battery monitoring. We work with premium brands like Fogstar, Victron, and Renogy for lithium, or quality AGM if lead-acid is your choice.
Get in touch for a free consultation →