New ve lithium ng 300 ah battery and ve bus bms ng

So I've been down this exact rabbit hole recently with my garden office setup, and thought it worth sharing for anyone else taking the plunge into Victron's newer LiFePO4 ecosystem.

I picked up a VE.Lithium NG 300Ah and the matching VE.Bus BMS NG a few months back — proper step up from my old cobbled-together setup. First thing I wanted to do was charge it to 100% for an initial capacity check, which sounds simple enough, but the BMS NG has some quirks worth knowing about.

The BMS NG communicates directly with the inverter/charger over VE.Bus, and it will override your charge settings if it decides the cells aren't happy. Out of the box, mine was being quite conservative — wouldn't let the MultiPlus push past about 95% until I'd done a few charge/discharge cycles. Whether that's by design or a config thing, I'm still not entirely sure.

A few things I've found useful:

• Make sure your VE.Configure software is up to date before you touch anything
• The BMS NG needs to be the only device controlling charge parameters — don't fight it with manual settings in the charger
• Victron's own documentation on this combo is decent but a bit scattered across their wiki

Has anyone else gone through the initial commissioning process with this pairing? Specifically curious whether others found the first full charge cycle took longer than expected, or if there's a trick to getting a proper 100% top-balance on the first go.

Would love to know how others are getting on with the NG range — feels like Victron have made it more integrated but also less transparent in some ways.

@WattNick looks like your post got cut off mid-sentence — we're all waiting to hear what you actually picked up! Finish that thought before this becomes the most suspenseful thread on the forum.

That said, if you're going the VE.Bus BMS NG route with the newer Smart Lithium range, one thing worth flagging that catches people out: the NG version uses a fundamentally different allow-to-charge/allow-to-discharge logic compared to the original VE.Bus BMS. The BMS Connection Cable pinout changed, so older Multiplus wiring doesn't map across cleanly. Victron's documentation looks thorough until you're actually bench-testing it at midnight wondering why your Multiplus-II keeps dropping out.

Running a similar setup on my narrowboat — Victron Smart Lithium 200Ah, MPPT 150/35, Cerbo GX. Happy to compare notes once you've posted the full spec.

Yeah @WattNick post got cut off, we're all just staring at an unfinished sentence here 😄

Assuming you went with the Victron LiFePO4 300Ah and the VE.Bus BMS NG — curious how you're finding the BMS integration tbh. I've got older Victron lithium in my static and the original BMS is a bit of a faff compared to what the NG supposedly offers.

Main thing I'd want to know — does the NG BMS actually play nicely with a Multiplus without jumping through hoops? That side of things always seems to be where people hit snags.

Finish the post mate 👍

@WattNick your post is truncated — guessing you went with the VE.Lithium NG 300Ah paired with the VE.Bus BMS NG? Running a similar combo in my shepherd's hut build and it's a solid pairing once you get the pre-charge relay sorted correctly.

Few things worth flagging when you do post the full details:

• The BMS NG communicates differently to the older VE.Bus BMS — don't assume your existing MultiPlus config carries over cleanly
• Pre-alarm outputs behave differently under low-temp conditions
• Make sure your Cerbo GX firmware is current before commissioning, older versions had quirks with the NG detection

Keen to see your full write-up once you recover the post. Particularly interested in how you've handled the charge disconnect logic if you're running solar alongside mains charging.

@WattNick the suspense is actually killing me — I've got a shepherd's hut build on the go and was literally googling the VE.Lithium NG range last night.

Few questions while we wait for the cliff-hanger ending:

• How are you finding the VE.Bus BMS NG integration compared to the older BMS? I've heard the pre-alarm outputs are much more sensible now
• Any gotchas with the Cerbo GX talking to it properly out of the box?
• What's your charge source — solar, shore, or both?

@Bomber78 has probably nailed what you ordered, but the why and the how it's actually performing is what I'm really after. Victron's marketing material is one thing, real-world cabin/garden office loads are another entirely. Don't leave us hanging! 😄