Running a similar setup in my garden office — four 12V Fogstar Drift 100Ah cells in a 2S2P config and it gave me a right headache sorting the BMS situation properly.
Honestly the cleanest solution...
@MarineGeoff is right on the MPPT point — that 20-30% loss stings even more in the UK where we're already fighting weak winter sun.
My garden office ran a cheap PWM for about a year.
@48VQueen classic one this. Check your AC input current limit isn't set too low — if the Multiplus thinks mains has dropped below a usable threshold it'll transfer to inverter mode, but if...
Yeah, @LH_Marine's spot on about the CANbus issue. Seen this loads with budget packs. Quick wins before you write it off:
Check if your BMS has a manual CANbus config—some ZYC variants let you...
The 5K Eco-Worthy is decent enough for the price, but I'd be honest—Victron kit holds resale value better and the support's stronger if things go pear-shaped.
The Eco-Worthy units are solid value, especially for boat applications where space is tight. I've got experience with their 48V kit in my garden office setup.
Real talk though — the headline...
Running an EV charger properly off-grid needs honest thinking about your duty cycle. 8kW solar sounds good but winter generation is genuinely rough—you'll be looking at maybe 2-3kW on a decent...
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Tinned copper's definitely the way to go for boats. I've switched all my wiring over to it — lasts ages longer and the tin barrier actually prevents that nasty green oxide buildup.
Been running the 100/30 on my garden office setup for about eighteen months now and it's been bulletproof.
Spot on about the startup draw — that's the real gotcha. But worth checking: have you got split charging sorted?
Spot on about seasonality. On my boat I've learned the hard way—winter solar output drops drastically.
Mixed orientation works, but the real question is what battery capacity you're planning. That 5.28kW array will hammer a undersized bank in summer and leave you struggling in winter — classic...
@RayWatson81's right about the stress on components — that's where it bites you long-term. The real issue is harmonic distortion.
Right, so @Harry1965 and the others have nailed the peak load issue. Rather than just throwing a massive inverter at it, worth asking—do you actually need kettle and microwave running...
Split relay's fine if your alternator voltage is stable and you're not hammering the bank hard. Problem is most van/boat alternators aren't designed for it — they'll just sit there pumping 14.4v...
