Swapped out the old shorepower setup on my 28ft sloop — here's what I went with

Been lurking on threads here for ages about boat electrics and finally bit the bullet this spring. Pulled out the knackered 240V hookup system that came with the boat and rebuilt the whole thing around a 200Ah lithium (a Fogstar Drift 200Ah) and a pair of 175W flexible panels on the coachroof. Running a Victron SmartSolar 100/30 into the bank, and a Victron Orion-Tr Smart DC-DC for charging off the Beta 20 engine when I'm motoring in and out of harbour.

The main reason I wanted to move away from shorepower was marina fees — my current berth charges something like £4.50 a night just for the hookup, which adds up fast over a full season. Between the solar and the alternator top-up I've not plugged into shore once since April. Running a 12V compressor fridge (Dometic CFX3 35), LED lighting throughout, VHF, chartplotter and the occasional laptop charge. Resting voltage rarely dips below 13.1V overnight, which I'm dead pleased with.

One thing I'm still not totally happy with is the flexible panels — there's a noticeable hotspot issue on the one near the boom shadow and I wonder if I should have gone rigid from the start despite the awkward mounting. Anyone else running flexibles on a coachroof long-term? How are they holding up after a couple of seasons?

@24V_Nerd nice one, always satisfying ripping out the old stuff. What did you go with for the inverter/charger combo? I did something similar on my 26ft bilge keeler last season — ended up with a Victron MultiPlus-II and honestly it's been faultless. The VE.Bus integration with the Cerbo GX means I can keep an eye on everything remotely which is dead handy when she's on the mooring.

Curious what you chose for batteries too — I went Fogstar Drift LiFePO4 and they've handled the marine environment better than I expected so far. Only thing I'd flag is making sure your cable runs are properly tinned marine-grade copper, learned that the hard way with my first attempt 😅

What's your typical power draw like — mostly at anchor or are you running off hookup regularly?

@24V_Nerd great project, really interested to see where you went with this. I did something similar on my 26ft bilge keeler a couple of years back — the old shorepower setup was an absolute nightmare, corroded connections everywhere and the isolation transformer had seen better days.

@JasonMoore raises a good point about the inverter/charger. I'd also be curious what you chose for battery monitoring — that was the bit I wrestled with longest. Ended up going with a Victron BMV-712 and honestly couldn't recommend it highly enough for a marine environment, the Bluetooth is handy when you're down in the cabin and don't want to crane your neck at a shunt display.

Also wondering whether you kept any 240V capability at all or gone fully 12/24V throughout? Curious how you're handling the galley if so.

Great thread @24V_Nerd, looking forward to hearing the full spec. One thing worth mentioning that often catches people out on boats — corrosion protection on all your connections is absolutely critical in a marine environment, far more so than a land-based install. Even stainless terminals can cause grief with salt air working its way in over time. I'd strongly recommend self-amalgamating tape over every terminal and a proper dielectric grease on any connectors before you button everything up. Also curious what you went with for battery monitoring — on my own boat I found a decent shunt-based monitor was worth every penny for keeping tabs on actual state of charge rather than guessing from voltage alone. Did you keep any 240V capability at all or gone fully 12/24V throughout? Some marinas still make it awkward if you can't take shorepower.

Not a boat owner myself — static caravan and tiny house are my world — but the core principles are identical and I've rebuilt enough 12V/24V systems to know where people go wrong.

One thing nobody's mentioned yet: corrosion protection on every single terminal. On a boat it'll eat bare copper joints alive inside a season. Doesn't matter how tidy your crimps are.

Also worth thinking hard about your battery chemistry choice before you commit. I run Fogstar Drift LiFePO4 cells in my van setup and the discharge curve alone makes the switch from AGM feel like upgrading from a candle to a floodlight. On a boat where weight matters, the energy density argument gets even stronger.

What's your actual daily consumption looking like? That number drives everything else — inverter sizing, battery bank, solar — and people consistently underestimate it.

Really looking forward to the full breakdown @24V_Nerd — boat rebuilds like this are always a goldmine of practical lessons.

One thing I'd add that doesn't always get enough attention in these discussions: corrosion protection on your connections. Marine environments are brutal compared to static installations, and even quality crimps and terminals can deteriorate surprisingly quickly if they're not properly tinned and sealed. I've seen perfectly solid electrical work on boats fall apart within a season because someone used standard automotive connectors rather than proper marine-grade.

Also curious what you've gone with for your battery monitoring — keeping track of state of charge on a boat where you might be away from any hookup for extended periods is a different challenge to a static setup. Coulomb counting vs voltage-based monitoring makes a real difference to how confidently you can manage your loads.

Wrong forum for me but my garden office Victron setup taught me one thing that translates perfectly to any marine build — never cheap out on the cable runs between your batteries and inverter, because that's where amateur hour really shows itself at 3am when everything's gone wrong.

Cabin build here so not marine either, but watching this thread closely. One thing I'd flag from my own install — waterproofing your connections properly is non-negotiable even if you're "inland." Learned that the hard way after a wet Scottish winter wrecked a terminal block I thought was fine.

Also curious what you went with for shore power isolation @24V_Nerd — galvanic corrosion is the sneaky killer on boats from what I've read. Isolation transformer or just a good galvanic isolator?