Handtruck build with 48v AND 12v loads? Input with 120VDC AND low power solar?

Bit of an unusual one this but I've seen weirder setups on here so thought I'd throw it out there 😄

Running a handtruck-style portable power unit for the boat and occasionally the cabin. Want to run 48v loads (main inverter stuff) and 12v loads (lighting, 12v fridge etc) off the same bank. Already using a Victron Orion DC-DC for the 12v side which works a treat, so that bit's sorted.

The tricky part is the input side. Primary charging will be 120VDC coming from a higher voltage solar array I've already got rigged up, but I also want to bolt on a small low-wattage panel directly — like a 50-100w trickle/maintenance situation for when it's just sat there.

Questions I keep circling back to:

• Anyone running a 48v lithium bank (Fogstar Drift cells) with a dual-input charge controller setup like this?
• Does anyone know if Victron's SmartSolar MPPT range handles the 120VDC input okay on the higher spec units? I know the 150/35 goes up to 150v Voc...
• Any gotchas with mixing a high-voltage array input alongside a low-power panel on the same controller, or would you just run two separate MPPTs?

I'm probably overthinking it but I'd rather plan it right than rewire it three times like I did with the cabin setup 😅

Curious whether anyone's done something similar on a portable rig — handtruck builds seem underrated for flexibility honestly. Drop your thoughts below!

Interesting setup @ExChippie94 — what battery chemistry are you going with? That 120VDC input is the bit that'd concern me most. Are you planning a dedicated DC-DC converter to step that down, or something like a Victron Orion?

Also worth clarifying — is the 48v side for inverter loads and the 12v purely for lighting/nav type stuff? Because if so, you might be better served running everything through a 48v bank and just dropping down to 12v via a converter rather than maintaining two separate banks. Keeps the BMS situation much simpler.

The dual voltage thing is doable but the wiring gets messy fast on something portable. What current draw are you expecting on each rail?

@ExChippie94 the 120VDC input is actually less exotic than it sounds — a good MPPT like the Victron SmartSolar can handle high-voltage DC strings, some models up to 150V input. So depending on your panel arrangement that could work cleanly.

For mixed 48V/12V loads on a portable unit, I'd look at a Victron Orion DC-DC converter for the 12V side rather than running a separate battery. Keeps it one bank, saves weight on a handtruck build.

What's the actual load split? If the 12V stuff is minor (lighting, instruments) the Orion makes sense. If it's substantial you might reconsider the architecture entirely.

Battery chemistry question from @Mike1980 is the right one to answer first though — that'll dictate your BMS options and how comfortable you are with the 120VDC input voltage in a mobile context.

@HazelPaddy is right about the Victron MPPT handling that input voltage — been running a SmartSolar 100/30 on the boat for a couple of years, solid bit of kit.

The 48v/12v dual bus is the more interesting challenge tbh. Couple of options:

• Orion-Tr DC-DC from Victron to step 48v down to 12v
• Or run everything native 48v and use a small isolated converter just for 12v loads

For a handtruck build I'd probably go Orion route — keeps it tidy and the non-isolated versions are pretty affordable now.

What are your 12v loads actually pulling? If it's just lighting/USB stuff a cheap meanwell converter might do it rather than a full Orion.

@BirchTrevor glad the 100/30 is working out — worth noting for @ExChippie94 that if the 120VDC panels are high-wattage you might need to step up to the SmartSolar 150/35 or similar to handle the current on the output side.

On the dual-voltage question — for 48v and 12v loads from a single bank, I'd strongly suggest a Victron Orion DC-DC converter to drop down to 12v rather than messing about with a split bank. Keeps everything clean and your 48v bank stays balanced.

For a handtruck build specifically, weight distribution matters more than people realise — keep the battery low and centred. I've done something similar for emergency backup on our boat and the Fogstar 48v LiFePO4 cells are cracking for the size.

What loads are you actually running at 12v? That'll determine whether a small Orion is sufficient.

Good thread this — exactly the kind of hybrid headache I love 😄

One thing nobody's mentioned yet: if you're running both 48v and 12v loads simultaneously, are you planning a DC-DC converter between the two banks, or keeping them completely separate with their own charging paths? On my narrowboat I went the DC-DC route (Victron Orion-Tr Smart) and it's been rock solid, but on a handtruck where weight and space matter, it might be worth asking whether your 12v loads are light enough to just run a small dedicated 12v LiFePO4 (Fogstar do decent small cells) rather than stepping down from 48v constantly.

What sort of 12v loads are we actually talking here? That'll probably dictate the most sensible architecture more than anything else.