Using 48V battery in 24V system

Been thinking about this a lot lately as I'm looking at upgrading my static caravan setup and the price difference between 48V and 24V lithium packs has got me wondering if there's a workaround.

Short answer from what I've researched: you can't just drop a 48V battery into a 24V system without some serious conversion in between. The voltage mismatch would cause real problems with your inverter, charge controller, and pretty much everything downstream.

That said, a few options people seem to go with:

• DC-DC step-down converter between the battery and your 24V bus — works but you lose efficiency and it's another point of failure
• Just upgrade the whole system to 48V — honestly this is what I'm leaning towards. Victron kit handles 48V beautifully and the efficiency gains are worth it
• Wire two 24V batteries in series if you're dead set on keeping 24V — but then you're spending more anyway

I've got a Fogstar 24V 100Ah at the moment and it's been brilliant, but the 48V Fogstar Drift packs are tempting for the capacity-per-pound value.

Main thing I'd say is — design around your battery voltage from the start rather than trying to bodge it afterwards. Learned that the hard way when I first set up.

Anyone here actually running a DC-DC converter between a 48V bank and a 24V system day-to-day? Curious whether it's practical or a headache in reality.

@CharlieStevens85 Short answer: don't do it without a proper DC-DC converter between the battery and your 24V loads/inverter.

That said, there's actually a better question hiding here — why not just upgrade the whole system to 48V? I made that jump on my Vivaro build last year and the efficiency gains are genuinely noticeable, especially once you're pulling serious current for EV charging or high-draw appliances.

Key considerations if you're staying 24V:

• A quality buck converter (Victron Orion-Tr series handles this well) will step 48V down safely
• You'll lose some efficiency in conversion — typically 3-8%
• BMS communication becomes more complex

Honestly though, for a static caravan, 48V native makes far more financial sense long-term. Fogstar and Pylontech both do excellent 48V rack batteries at competitive prices right now.

What's your current inverter situation?

@CharlieStevens85 worth noting that even with a quality DC-DC converter in the mix, you're adding another point of failure and efficiency losses — typically 3-5% through the conversion stage. On a static caravan setup where you're not weight-limited, I'd genuinely question why you wouldn't just go native 48V and swap out your inverter/charger at the same time. Victron Multiplus-II in 48V spec isn't that much more than the 24V equivalent, and the higher voltage means thinner cable runs too which saves on copper costs.

If your existing 24V kit is relatively new and you're wedded to it, @VivaroWanderer is right — a proper Orion or similar isolated DC-DC is the only sensible route. Just don't cheap out on it.

@CharlieStevens85 The price differential is real but I'd push back on the framing slightly — if you're seriously considering an upgrade, you might as well jump to a proper 48V system entirely. Swapping inverter/charger, MPPT and cabling is less painful than it sounds, and Victron's 48V Multiplus range is actually better value per kW than the 24V equivalents once you factor in efficiency gains and reduced cable sizing costs.

I ran a 24V system in my shepherd's hut for three years before converting everything to 48V with a Fogstar Drift 48V pack — the difference in cable losses alone was noticeable. Thinner cable, cooler connections, less voltage sag under load.

The DC-DC converter route @VivaroWanderer mentions works, but you're essentially buying two systems' worth of complexity for one system's worth of benefit.

@CharlieStevens85 One thing nobody's mentioned yet — check what inverter you're actually planning to run. A lot of the more affordable pure sine wave inverters in the 1-3kW range are 24V native, and decent 48V equivalents can eat into that supposed cost saving pretty sharpish. I made a similar calculation error when I was speccing my off-grid shed setup and nearly talked myself into a false economy. If your loads are already 24V and your existing cabling is sized for it, sometimes the sensible move is just buying a quality 24V lithium pack rather than retrofitting around a cheaper 48V battery. What inverter are you looking at specifically?