Battery upgrade for my 2015 Elddis - worth it or should I just replace the leisure battery?

Had this exact dilemma two years ago with my Hymer. Ended up upgrading the whole setup and honestly, best decision I made.

The thing is, a standard leisure battery in a 2015 Elddis is probably a basic lead-acid setup—decent for occasional use but you'll hit its limits quickly if you're doing any serious off-grid time. Just swapping it for another similar battery is kicking the can down the road, really.

My approach was to go LiFePO4. Yes, it's a bigger outlay upfront (I went with a Fogstar 100Ah and integrated a Victron MPPT), but the difference in performance is night and day. You get:

• Proper depth of discharge (you can actually use the full capacity, not just 50%)
• Faster charging from solar
• Way longer lifespan
• Better weight distribution than those chunky lead-acid blocks

The investment paid for itself through fuel savings alone—running less generator time, smoother power delivery to the fridge and heating.

That said, if you're just doing occasional weekend trips and aren't bothered about modern creature comforts, a straightforward leisure battery replacement might be fine. But if you're thinking long-term or planning longer trips, the upgrade is worth considering.

What's your typical usage pattern? That'll probably be the deciding factor. Also worth checking what charging setup you've got onboard—sometimes that's the real bottleneck rather than the battery itself.

Would be interested to hear what route you're leaning towards.

Depends entirely on your usage pattern, to be honest. If you're doing weekend trips with minimal draw, replacing the leisure battery is fine—a decent 100Ah AGM will run you £300-400 and last 5-7 years.

But if you're van-dwelling or running a fridge/inverter regularly, a single battery becomes a bottleneck fast. I went LiFePO₄ in my setup (Victron 200Ah) specifically because the charge/discharge cycles needed meant a lead-acid was getting hammered constantly.

The hidden cost most people miss: you'll need a proper MPPT charger and maybe a DC-DC unit to support it properly. That's another £400-600 minimum.

Worth calculating your actual Ah demand first. How many days between hookups? What appliances are non-negotiable? That'll answer whether you're looking at a £400 fix or a proper £1.5k system upgrade.

Been there with my motorhome — upgrading from a single flooded leisure battery was like going from a candle to solar panels, metaphorically speaking. If you're actually using the van rather than just parking it at the in-laws', a proper lithium setup with a decent Victron charger will pay for itself in peace of mind alone. The catch? Initial outlay is brutal. But if you're doing more than three nights a month, that stock Elddis battery will have you rationing the kettle like it's 1974. LiFePO₄ cycles are brutal on lead-acid — they'll age that leisure battery faster than a Burnham-on-Sea caravan in a heatwave. Depends if you want reliable power or a very expensive paperweight.

I went through this with my van conversion last year. Started with the standard leisure battery, kept running flat by day two. The real question isn't just about capacity—it's about what you're actually powering.

If you've got a fridge, heating, or any decent load, a single leisure battery won't cut it. I replaced mine with a Victron lithium setup and added a small 400W solar array. Sounds pricey, but the maths work out: you stop buying hookups at campsites, and the battery lasts years longer than flooded lead-acid.

That said, if it's genuinely just lights and phone charging for weekends, stick with replacing the leisure battery. But check your actual amp-hours first—most standard motorhome setups ship underspecced.

What's drawing your power?

The real question is what's actually draining your battery. If you're just topping up a knackered leisure battery every trip, you're throwing good money after bad — but if you're genuinely using 12V kit (fridge, heater, lights), a single battery won't cut it.

Two years ago I upgraded my setup with a 200Ah LiFePO4 and it transformed things. However, that's only worth doing if your van's got decent solar and/or a proper charger. Otherwise you're just buying an expensive battery to charge from hook-up every night.

My take: if it's a 2015 Elddis, check what charging infrastructure you've already got. No solar or split charger? Replace the leisure battery with a decent flooded one (Trojan or similar) and revisit in a couple of years. Got solar panels or willing to add them? Then upgrade makes sense.

What's your current charging setup?

@ExpertCamper and @ValleyOffGrid have nailed it — this is about your actual usage pattern, not just battery age.

Before you spend anything, I'd grab a multimeter and log what you're actually drawing. Run your fridge, lights, heating for a typical day and see where you stand. A 2015 Elddis standard setup is usually 85-110Ah flooded, which sounds plenty until you realise they're only usable to about 50% depth without killing them prematurely.

If you're constantly flat, a single LiFePO4 upgrade (say 100Ah Victron or Fogstar) with a decent charger makes massive difference. But if the original battery's only two years old and you're not actually draining it that hard, you might just need better charging — a CTEK or Victron DC-DC charger sorting your alternator output could be the answer at half the cost.

What's your typical drain like over a night?

Depends what you're actually using it for, mate. If it's just weekends with the telly and a bit of heating, replacing the leisure battery might do the job. But if you're doing proper off-grid stretches, you'll hit the same wall again in a few years.

I went the upgrade route on mine — swapped in a Fogstar lithium with a Victron controller and haven't looked back. Upfront cost stung, but the usable capacity difference is massive. A standard lead-acid gives you maybe 40-50% depth of discharge safely; lithium you can run harder without killing it.

What's your typical usage like? That'll tell you if you need the full upgrade or just a better leisure battery to get by.

Just done a similar upgrade in my van conversion so slightly different context but the same principles apply. What's your actual Ah consumption per day? Worth working that out before spending anything — I used a basic clamp meter for a week before deciding anything.

Also worth checking whether your 2015 Elddis has a proper B2B charger or just relies on the split-charge relay. If it's the latter, you could be undercharging whatever battery you fit, new or old. Victron do decent B2Bs if you do end up going that route.

Been through this twice now — once on the motorhome, once on the narrowboat. The honest answer is: if you're replacing like-for-like, you're just delaying the real decision.

Worth checking what your Elddis's B2B charger situation is before committing to lithium though. Some older habitation systems don't play nicely without an upgrade there too. Victron Orion or similar sorts it, but that's extra cost to factor in.

@Thommo9 is right to ask about usage — but also think about storage. Lithium doesn't sulphate sitting over winter like AGM does, which for a seasonal motorhome matters a lot.