EG4 12000XP Version2 vs ECO-WORTHY Liber 18KT Off-grid Three-phase Inverter

Never actually run three-phase myself — the narrowboat runs a fairly modest Victron Multiplus-II 3kVA setup and the van was always 12V anyway — but I've been quietly watching the three-phase inverter market because there's a static workshop build on my radar for next year.

The EG4 12000XP V2 gets talked about a lot on the American forums, but sourcing support and warranty for it here in the UK feels like it could turn into a proper headache. Has anyone actually had to claim warranty on one from this side of the Atlantic?

The ECO-WORTHY unit is more readily available through UK distributors, which matters enormously when something goes wrong at 11pm on a Sunday in January. That said, 18kW three-phase is a serious bit of kit and I'd want to know the BMS comms are solid before committing — anyone running it alongside Pylontech or Fogstar Drift cells?

A few things I'm genuinely curious about for the thread:

• Real-world efficiency figures at partial load (not the spec sheet numbers)
• CAN bus / RS485 comms reliability with common UK battery brands
• Grid-tie or off-grid certification — this matters for anyone on a rural property potentially connecting to DNO

Would love to hear from anyone who's actually deployed either unit rather than just benchmarked them on paper. There's a real gap in honest long-term UK experience with both of these, and this thread could fill it nicely.

Hey @StormySocket, three-phase is a fascinating rabbit hole to fall down even just theoretically! One thing worth flagging that sometimes catches people out — most domestic UK off-grid setups genuinely don't need three-phase unless you're running specific motors or equipment that demands it (large workshop machinery, certain heat pumps, that sort of thing). Given your narrowboat background you're probably already thinking in terms of actual load requirements, which is the right approach. If you do go down that route, balancing loads across the phases becomes a real consideration that single-phase folks never have to worry about. What's the actual application you're eyeing these up for? That'd probably help narrow down whether either of those units is even the right fit, or whether something else entirely might suit better.

Worth noting if you're looking at either of these units for a static setup — the ECO-WORTHY tends to have spottier UK support than something like the EG4 line. Parts availability and firmware updates matter a lot when something goes wrong six months in.

My caravan runs single-phase obviously, but I've been through enough inverter headaches to know that after-sales support is genuinely the deciding factor at this price point. EG4's documentation is at least reasonably solid.

Also worth checking whether your DNO has any concerns about three-phase inverters on a grid-tied or hybrid setup — that's a paperwork rabbit hole some people don't anticipate until it's too late.

Really interesting thread to stumble across — I ran three-phase machinery for years on the farm before I downsized to my current off-grid setup, and the jump from single-phase thinking to three-phase is genuinely a different mindset.

One thing I'd add that nobody's mentioned yet: load balancing across phases is where a lot of people come unstuck with these hybrid inverters. If you're not spreading loads sensibly, you can end up hammering one phase whilst the others loaf about, which plays havoc with efficiency figures you'd expect on paper.

The EG4 12000XP does have decent phase-balancing logic built in from what I've read, though I've not personally tested it. Anyone here actually running one with an asymmetric load profile? Would love to see real data rather than spec-sheet promises — that's always where these units either earn their keep or fall apart.

@Lee1996 good point on support — had a similar headache sourcing bits for a less common unit a while back, ended up just going Victron because at least there's actual UK stock and people who know it.

Not running three-phase myself (cabin's just a modest 24V Fogstar/Victron setup, nothing exotic) but I've been vaguely curious about this space. The EG4 stuff seems well regarded on the US forums but I genuinely don't know how that translates over here — different grid regs, support, all that.

@ExFarmer90 interested what you ended up with after the farm downsizing actually, sounds like you'd have useful real-world comparison.