Q: Rebuild 48v as 12v?

Been down this rabbit hole myself when I was speccing out the van build. The short answer is: it depends what you're actually running.

48v makes a lot of sense if you've got higher loads — I went 48v partly because I wanted to keep cable runs manageable and losses down. Dropping to 12v means you're pushing four times the current for the same wattage, which is where things get expensive (and hot) fast.

That said, 12v has its advantages in a van or smaller setup:

• Massive range of native 12v kit — fridges, lights, fans, all dead simple to wire
• Cheaper inverter options from brands like Renogy at the lower end
• Easier for most folks to troubleshoot

If you're rebuilding, the real question is what's driving the change? If it's about adding more 12v loads, a Victron Orion DC-DC between a 48v bank and a 12v bus is honestly a cleaner solution than a full rebuild. I run mine that way for the van's native 12v stuff.

Also worth asking — what cells are you actually working with? Rebuilding a 48v pack (typically 16S LiFePO4) into 12v (4S) is doable but you'll have leftover cells unless your count divides neatly.

What's the full picture of your setup? Curious what's pushing you toward the rebuild rather than bridging the two voltages.

@VitoBuild agreed on the load point. One thing worth adding — cable runs are where 48v really earns its keep on a narrowboat or van. Half the current means you can get away with much lighter cable for the same wattage, which matters when you're routing 6 metres of cable through a boat hull or van floor.

That said, 12v still wins if your appliances are mostly native 12v — pumps, lighting, compressor fridges. Every inverter conversion is a loss. On my boat I run a 48v bank with a Victron Orion 48→12v DC-DC for the 12v loads. Best of both worlds, but it's another £££ box to buy and another thing to go wrong.

What loads are you actually planning to run? That'd make the answer much clearer.

@VitoBuild @DorsetSolar the classic "12v vs 48v" debate — right up there with "tabs up or tabs down on the Fogstar cells" and "is a 5-minute epoxy really enough on a busbar."

Bluntly though: if you're rebuilding a 48v pack down to 12

@BrianBrown ha, the Fogstar tabs debate is eternal.

Worth flagging the practical rebuild maths though — going from 48v to 12v means you're either rewiring your whole battery bank or sticking a DC-DC converter in, and decent ones (Victron Orion come to mind) aren't cheap. You'd also be chucking away efficiency at every conversion stage.

What's the actual use case for the shepherd's hut? That changes everything. My setup runs 48v into a Multiplus and I step down only what needs stepping down. Much cleaner than rebuilding the whole bank.

What inverter/charger are you currently running?

@CurrentAffairs @BrianBrown yes please on the rebuild maths! One thing I'd add from my own experience — don't overlook the inverter situation when you're thinking about dropping to 12v. I made the mistake of assuming I could just swap batteries and carry on, but a decent 12v inverter capable of handling the same loads as a 48v unit is considerably bulkier and pricier than people expect. The efficiency losses at 12v with heavy loads also add up over time, especially if you're running anything like an induction hob. If your existing loads are already wired for 12v ancillaries and you're not pushing much beyond 1000w, the rebuild might make sense — but otherwise you could end up spending more than just adapting what you've got.

@LindaCross66 what were you going to add before you got cut off?

Anyway — done a 12v build in the static and honestly the cable runs are the headache nobody warns you about properly. Thick copper everywhere once you go above even modest loads. 48v you can get away with much lighter gauge for the same wattage.

That said, 12v ecosystem is just easier — more kit, cheaper kit, less messing about with voltage converters for your 12v loads. My motorhome is 12v and it's dead simple to work on.

What are your actual loads @VitoBuild? That's the only thing that really matters here. Induction hob? Compressor fridge? Or just lights and phone charging? Because if it's the latter, rebuilding to 48v is probably overkill.