OFFGRID MultiPlus-II 48/5000 & Pylontech US5000

Been down this exact rabbit hole with my narrowboat setup, so this might save someone a headache.

When I first got my Victron MultiPlus-II talking to the Pylontech US5000s, I had the same maddening situation — batteries showing full, panels throwing out decent output, and the inverter still insisting on pulling from the shore power hookup at the marina.

The culprit for me was the ESS Assistant. It's designed for grid-tied systems where you want to offset mains usage — brilliant for a house in Spain apparently, not so brilliant when you're genuinely off-grid or just want to run entirely from solar and batteries.

A few things worth checking if you're in a similar spot:

• ESS vs Off-Grid mode — ESS assumes a grid connection is desirable. If you're truly off-grid, you might not want ESS installed at all
• Grid setpoint — even with batteries full, ESS can be configured to maintain a small grid draw; worth checking that value in VEConfigure
• "External Control" on the inverter display — this usually means ESS or DVCC is managing it, not a fault as such, just the assistant taking the wheel
• DVCC settings — if Pylontech BMS is talking to the Cerbo/CCGX, make sure CVL and CCL values are coming through correctly

On the narrowboat I ended up ditching ESS entirely and running in inverter-only mode with the MultiPlus set to ignore the landline unless batteries drop below a threshold. Much cleaner behaviour.

Anyone else running Pylontechs with a MultiPlus-II in a genuinely off-grid setup? Curious whether others have found ESS

Great thread @TonyOliver – narrowboat installs are their own beast aren't they!

One thing worth flagging that catches people out: make sure your VE.Bus cable between the MultiPlus-II and your CCGX or Cerbo is properly seated. I had intermittent comms dropouts with my US5000s that drove me absolutely spare, turned out to be a slightly loose connector rather than any settings issue.

Also worth checking your battery firmware via the Pylontech console tool before assuming any odd behaviour is configuration related. Outdated firmware on the BMS can cause some genuinely baffling charge/discharge quirks that look like inverter problems.

What does your current charge current limit look like in VEConfig? With US5000s you've got more headroom than most people realise, though I'd still build up gradually rather than hammering them straight away.

Worth adding from my shepherd's hut setup — the DVCC settings are where people trip up most. Make sure you've got DVCC enabled and SVS/STS switched on, then let the Pylontech BMS actually do the talking via the VE.Can connection rather than overriding charge voltages manually in VEConfig.

Took me an embarrassing amount of time to realise I'd been fighting the BMS by setting custom absorption voltages. Once I stepped back and let DVCC handle it, the whole system just... behaved.

Also double-check your Cerbo GX firmware is current — there were some known quirks with Pylontech comms on older builds that caused the battery state to report incorrectly in VRM.

@TonyOliver one thing I'd add — check your VE.Bus firmware is actually current before you do anything else. Had mine seemingly configured correctly on the cabin setup but the MultiPlus-II was silently ignoring the BMS comms because of a firmware mismatch. Wasted an afternoon on that.

Also worth noting: the US5000 reports SOC differently to the older US3000C — the charge/discharge curves aren't identical so don't just copy settings from older guides verbatim. Plenty of outdated walkthroughs floating about.

@WD40Wizard11 — DVCC point is solid, though worth being precise: you specifically want SVS (Shared Voltage Sense) enabled too, not just DVCC on its own.

Really useful thread — just what I needed as I'm in the middle of planning a similar setup for my static caravan.

Quick question for anyone who's done this: with the Pylontech US5000s, how many units are you running before you feel comfortable with overnight loads? I've got a fairly modest setup (fridge, a couple of lights, phone charging) but I'm genuinely unsure whether one US5000 is realistic or whether I'd be chasing my tail by the morning.

Also — is the MultiPlus-II 48/5000 overkill for smaller setups, or does the headroom actually pay off long-term? I've seen people recommend sizing up but the price jump is significant.

@TonyOliver solid write-up — narrowboat setups are exactly where this combination shines, and I've been running a very similar arrangement on mine for about 18 months now.

One thing nobody's mentioned yet: Pylontech's recommended charge current limits are often lower than what the MultiPlus-II will default to. With US5000s you want to pull those figures directly from the Pylontech BESS documentation and set your charge current override in VEConfig accordingly — don't rely solely on the BMS CAN data to protect you there.

Also worth enabling the ESS Assistant rather than running standalone inverter mode if you've got any shore power connection at all. On a narrowboat with marina hookups, the seamless transfer logic alone is worth the faff of setting it up properly.

@SueJohnson same advice applies to static caravans — ESS gives you far more flexibility when grid is occasionally available.