Lithium vs AGM: the key differences

• Weight — lithium (LiFePO4) batteries are typically less than half the weight of an equivalent AGM battery, which matters a lot for payload in a camper van or self-build
• Usable capacity — lithium batteries can be discharged to around 80 to 100% of their rated capacity, while AGM batteries are usually limited to around 50% to protect their lifespan, so a lithium battery gives you more usable power for the same rated size
• Lifespan — lithium batteries commonly offer 2,000 to 5,000+ charge cycles, compared to around 300 to 500 cycles for AGM, meaning a lithium battery can outlast several AGM replacements
• Charging speed — lithium batteries accept charge much faster, which is useful if you're relying on solar or a short drive to top up
• Upfront cost — AGM batteries are cheaper to buy initially, so they can suit lighter budgets or lower-demand setups, though lithium tends to work out better value over its longer lifespan
• Maintenance — both are maintenance-free and safe for use in enclosed spaces, unlike older wet lead-acid batteries

Why Fogstar? ⚡

Fogstar batteries are built specifically for UK camper van, self-build and motorhome electrics, with a range that covers everything from budget-friendly options through to high-spec lithium packs. As an authorised Fogstar dealer, we back every battery with the same warranty you'd get buying direct, alongside genuine stock, fast delivery and support from a team that actually uses this gear in our own builds.

Shop the Fogstar range here:
https://sonniesadventures.com/collections/fogstar

Don't forget: 10% off for new customers 🎉

New to Sonnie's Adventures? Use code FOGSTAR10 at checkout to save 10% on any Fogstar battery. Valid for new customers throughout July and August 2026, with free delivery and full authorised dealer warranty included.

FAQs

Is lithium better than AGM for a camper van?

For most camper van and self-build setups, yes, thanks to the lower weight, higher usable capacity and longer lifespan. AGM remains a solid, budget-friendly choice for lighter use or occasional trips.

Can I replace an AGM battery with lithium directly?

In most cases yes, but you'll want to check your charging system (solar controller, DC-DC charger, mains charger) is lithium-compatible first, as lithium batteries charge differently to AGM.

How long do Fogstar lithium batteries last?

Fogstar's lithium batteries are rated for thousands of charge cycles, which typically translates to many years of regular use depending on how the battery is used and maintained.

Does the FOGSTAR10 code work on any Fogstar battery?

Yes, FOGSTAR10 applies to Fogstar batteries across the range for new customers, valid throughout July and August 2026.

Is AGM still a good option in 2026?

Yes, particularly for lower-budget builds or setups with lighter power demands, where the lower upfront cost of AGM makes sense.