The upfront price comparison is brutal. A 120Ah AGM is ~£180. A 120Ah TITAN lithium is ~£700. Three to four times more. So why bother?

Two reasons. Usable capacity and cycle life.

You can only safely use ~50% of a lead-acid AGM before you start chewing through cycle life. So in usable terms, that 120Ah AGM is really a 60Ah battery. A 120Ah TITAN is a 120Ah battery in usable terms. To match the TITAN's usable capacity you need a 240Ah lead-acid bank - roughly £360 of AGM versus £700 of lithium. The gap is already shrinking.

Then there's cycle life. A 240Ah AGM bank used daily lasts ~2 years before its usable capacity has halved. A 120Ah TITAN used the same way is still at 95% after 3 years and is projected to last 15-30 years on typical leisure / marine duty cycles. Over a 15-year window you'd be on your 7th set of AGM (around £2,500 of AGM) to keep the same usable capacity that one TITAN gives you (£700). The TITAN is cheaper by year 4 and the gap only widens from there.

Add the lifetime warranty (transferable, repair-first, no registration), the in-app monitoring, the half-the-weight payload back in the van, and the comfort of not having to think about it - and lithium becomes the right call for almost any frequent-use setup.

If any of these describe your setup, lead-acid is probably still the right call - we'd rather you put your money in the right place:

• You use it less than 10 days a year: a lead-acid bank lasts 5-7 years even with light use. Lithium's cycle-life advantage doesn't matter.
• Cost-of-capital matters more than total cost: students, occasional users, short-term boat charterers, garden offices used 6 times a year. The upfront-cost math doesn't justify lithium yet.
• Starting a car or motorbike (not Labs): starter batteries are a different chemistry and a different duty cycle. Lead-acid is still mainstream there. We're working on the lithium starter side via TITAN Labs but that's prototype-grade.
• You're storing the boat indefinitely with no charging: a lithium pack will sit happily for years on the right SOC, but if you're literally walking away and never coming back, a lead-acid is forgiving.
• Strict legacy installs: some classic vehicles have charging systems that don't suit lithium even with a B2B charger. We'd rather flag that than sell into a problem.

If your use case isn't in the list above, lithium is almost certainly the right call.

Three things change when you move from lead-acid to lithium:

1. Your existing charger is almost always fine. Fixed-voltage AGM chargers sit at voltages TITAN's BMS will happily accept - we've tested the common ones (Schaudt, CBE, Sargent) and they work without any modification. Modern multi-stage chargers (CTEK, NOCO, Victron, Sterling) have proper LiFePO4 profiles that charge faster and finish cleaner. Either way, the charger compatibility page lists the recommended setting per brand.

2. Your SOC reading needs to be recalibrated. The dashboard SOC gauge in a campervan is usually a voltmeter assuming a lead-acid curve. Lithium has a flat voltage curve - the reading will look mostly fine, then jump from 30% to 5% near empty. Either install a proper coulomb-counting SOC meter (Victron BMV-712 or similar) or just use the TITAN App V2 SOC reading instead, which is accurate.

3. The bank can charge a lot faster. Your existing alternator and solar can now charge the lithium 3-5x faster. For most installs that's fine. For some - especially older alternators that weren't designed to deliver high current for sustained periods - we'd recommend a B2B (DC-DC) charger like the Victron Orion or Sterling BB1240. More detail on alternator charging.

That's it. The physical install is the same - mount, connect positive to positive, negative to negative, secure with the tie-down. Most campervans and boats are a 15-minute swap.