Using the Duracell D350-M1A to grid-feed from a 48V battery - "PV Baseload" from an off-grid system

Interesting thread — this is something I've been mulling over for the narrowboat setup actually.

The idea of bleeding off excess capacity into the grid rather than just dumping it through a diverter makes a lot of sense, especially in summer when the 48V bank is sitting at 100% by mid-morning and there's nowhere useful for the power to go.

A few things I'd want to get right before attempting this:

• BMS communication — does the D350-M1A play nicely with Victron's ecosystem via CAN bus? That's the critical bit for me. Without proper handshaking between the inverter and BMS, you're asking for trouble
• G98/G99 compliance — grid feed in the UK isn't just plug and play. Depending on export levels you may need DNO notification at minimum
• Round-trip efficiency — by the time you've charged the bank, sat on the energy, and then exported it, what are you actually gaining vs a direct divert to a immersion or EV charger?

On the EV charging side I've found a well-timed DC divert via a Zappi in eco mode does a similar job without the grid export complexity.

Has anyone actually got this working with a Fogstar or similar 48V lithium pack? Curious whether the D350-M1A's BMS is chatty enough to satisfy a Multiplus-II properly or whether you end up having to manually set charge limits.

@PanelHarry "bleeding off excess capacity" sounds like something you'd say to a doctor, not a solar installer 😄

But seriously, the Duracell D350-M1A isn't something I've come across — anyone got a datasheet link? Bit sceptical of Duracell playing in the 48V inverter space,

@PanelHarry the concept is solid but the Duracell D350-M1A isn't something I recognise from any current UK distribution catalogue — worth double-checking the model reference before you spec anything around it, as you don't want to be hunting for warranty support that doesn't exist here.

For grid-feed from a 48V bank the Victron Quattro + MultiPlus-II route is well-trodden and actually supported under G98/G99 notification properly. I've done something adjacent on my motorhome setup — obviously not grid-tied — but the charge/discharge logic through a Cerbo GX is impressive once you dial in the SOC thresholds.

The real gotcha with "PV baseload" injection is your DNO notification obligations. Many people skip that step and it causes problems later.

@SimonKelly same — I had a proper rummage through the usual suspects (Bimble, BMS World, even phoned a couple of distributors) and the D350-M1A doesn't ring any bells at all. Could be a rebadged unit under a different SKU, or possibly a model designation that only exists in certain markets?

Worth checking whether the spec sheet is genuine before anyone gets too excited about grid-feed capability — there's a lot of "creative labelling" floating around at the moment, especially on units coming through grey import channels.

@PanelHarry what's your source for this one? If it's a legit product with real DNO compliance documentation I'd genuinely love to know more — the idea of a clean export pathway from a 48V off-grid bank is exactly what I've been trying to solve for my static caravan setup without bodging together a Victron MultiPlus and crossing everything.

@SimonKelly @EcoFlow_Nerd yeah I'd be cautious here — if none of the usual UK distributors are stocking it, that's a red flag before you even get to the grid-feed legality side of things.

Grid export from a standalone off-grid system opens a whole separate can of worms anyway — G98/G99 compliance, DNO notification, inverter certification. Most hybrid inverters that are certified for UK grid-tie (Victron Multiplus-II with the right firmware, for example) have a very specific approval path.

The "PV baseload bleed" concept itself isn't daft — I've looked at something similar for my setup — but I'd want to start with kit that actually exists on a UK datasheet before designing a system around it. Has anyone found an actual spec sheet for this unit, or is this possibly a model number that got garbled somewhere along the way?

@PanelHarry @DODQueen the narrowboat angle makes this even trickier — marina shore power hookups add another layer of compliance headache on top of the usual G98/G99 export notification requirements.

I'd be wary of building any grid-feed setup around a product nobody can actually verify exists in the UK market. If the D350-M1A turns out to be a phantom model number, you're potentially looking at equipment without proper UKCA/CE certification, which your DNO won't want to hear about.

For the "PV baseload bleed" concept itself though — it's genuinely worth pursuing with proven kit. Plenty of folk are doing similar with the Victron Multiplus-II and proper grid-tie inverters. Get the foundation right before worrying about which battery unit to hang off the back of it.