ZYC 100ah 48v Lithium battery not reflect in victron Multiplus II GX.

Had a similar issue with a budget lithium setup a couple of years back. The Multiplus II GX can be finicky with third-party batteries, especially the cheaper ones that don't have proper Victron integration.

First thing I'd check is whether your ZYC battery's BMS is actually communicating via CAN bus. Most budget Chinese cells either come with a basic BMS that only handles cell balancing or they require specific firmware updates to play nicely with Victron gear. Worth checking if there's a firmware version number anywhere on the unit or in the documentation.

What I ended up doing was configuring the Multiplus manually. You can set it to accept the battery as a generic lithium profile in the settings menu, though you lose some of the clever monitoring features. Not ideal, but it keeps things running.

One thing that caught me out initially — make sure your CAN termination resistors are properly fitted if you're daisy-chaining devices. Easy thing to overlook but it'll cause all sorts of communication gremlins.

Have you tried a factory reset on the GX touchscreen? Sounds daft, but sometimes it helps when it's not recognising a newly connected device.

Worth knowing: I've had better luck with Renogy and Fogstar lithium batteries for reliable Victron integration, though obviously that doesn't help you now. The ZYC packs aren't terrible value for emergency backup or cabin use, just need coaxing a bit.

What's your CAN configuration looking like? That's usually where the problem sits with these setups.

I'd be cautious with ZYC batteries mate—they're typically rebranded Chinese cells without proper CANbus integration. The Multiplus II GX relies on that communication layer to read SOC, voltage balancing, and cell temps accurately.

A few things to check:

CANbus connection: Is the battery's CAN port actually wired to your Multiplus II? Some budget packs ship with dodgy connectors that look connected but aren't making proper contact.

BMS firmware: Does the ZYC unit have updatable firmware? Worth checking their documentation for Victron compatibility—sometimes a firmware flash sorts it.

Alternative approach: If it's not showing up, you could run it in "dumb" mode with a Victron BMV-712 monitoring the shunt separately, though you'll lose integrated battery management.

What's your actual system config—how many cells strung together? That sometimes matters with third-party BMS protocols.

Ah, ZYC—the battery equivalent of a motorhome with no sump plug drain. Your Multiplus II GX speaks fluent Victron but ZYC speaks... let's say creative Chinese.

Have you tried a firmware update on the GX? Sometimes it helps, but honestly if there's no proper CANbus handshake happening, you're basically asking a Victron to read tea leaves.

What comms cable are you using—USB or actual CAN? Also worth checking if the BMS is even trying to send data rather than just sitting there looking mysterious like my leisure battery in January.

Might be worth ringing Victron support before you go full nuclear and replace it with something like a Fogstar or Renogy—at least those play nicely with the GX setup.

Had a ZYC equivalent in my shepherds hut setup for about six months. Pain in the arse, honestly. The issue is they don't broadcast proper state-of-charge data over CANbus, so the Multiplus II GX just sits there confused, treating it like a dumb lead-acid.

Few things worth trying: check if there's a firmware update for the battery's BMS (sometimes helps), or you could manually set charge parameters in the Multiplus via VRM if you're feeling brave. But real talk—you'll never get full integration like you would with a proper Victron LiFePO4.

@VivaroWanderer's right about the rebranding issue. For what you've probably paid, a Fogstar or Renogy setup would've given you actual support headaches instead of just headaches.

The core issue: ZYC batteries lack proper CANbus implementation, so the Multiplus II GX can't communicate state of charge or health data. You'll get basic voltage monitoring only.

Workaround options:

1. Manual configuration — Set the Multiplus to "fixed" battery type rather than auto-detect. Not ideal, but it'll charge/discharge without throwing errors.

2. Third-party BMS gateway — Something like a Victron Lynx Shunt with manual inputs, though this is a band-aid solution.

3. Accept the limitation — If the battery's internal BMS is decent (and most aren't), it'll manage itself. Just monitor manually via the BMS app.

Honest take: you've bought a battery that wasn't designed for integration with your inverter. @OffGridTerry's right about the integration gap. For the money, you'd have been better off with a Fogstar or even a Renogy unit with proper Victron support.

What's your current error message showing?

Cheers for the replies, lads. Worth checking a few practical things before you assume it's a dead loss though:

Have you got the battery's CANbus configured properly? Some budget lithium packs need manual setup in VE.Can or similar—it's not always plug-and-play even with decent batteries.

Also, what's your Multiplus II firmware at? Victron pushes updates fairly regularly that improve third-party compatibility, so it's worth running the latest if you haven't already.

As a workaround, you could try a Victron SmartShunt as an intermediary—it'll at least give you proper SOC readouts even if the Multiplus won't play ball directly with the ZYC BMS. Not ideal long-term, but it'll get you monitoring properly.

What error messages are you seeing on the GX display, if any?

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 toggle it on, buried in the settings. Also verify the Multiplus firmware's up to date; older versions were proper rubbish with non-Victron batteries.

If it's still not showing, you might need to set it as a generic lithium in the GX config rather than expecting auto-detection. Not ideal, but it'll at least monitor voltage and temperature.

The boat I'm working on has a similar frankenstein setup. Gets there in the end, just requires a bit of faffing. What's your actual error message showing?

Had this exact scenario with a Fogstar pack in my cabin setup about eighteen months back. The ZYC units are notorious for dodgy CANbus implementation—they'll charge fine but the GX display stays blank because there's no proper handshake happening.

Worth checking: is your BMS actually outputting a CANbus signal? Some of the cheaper variants ship with it disabled by default. You can force the Multiplus II into "dumb" mode via Victron Connect, but you'll lose all monitoring. Not ideal for off-grid where you need to track state of charge religiously.

If the BMS is genuinely non-compliant, you're looking at either retrofitting a proper Victron-compatible unit or accepting manual monitoring. Frustrating, but unfortunately fairly common with budget lithium.

The ZYC packs typically use a JK or DALY BMS internally, and neither talks to Victron natively without a separate CANbus adaptor or a properly configured DVCC setup. What you're probably seeing is the MPII-GX just not "seeing" the battery at all in the Battery Monitor section — it'll still charge/discharge, but you lose all the clever SoC integration.

Check your VE.Configure settings: set the battery type to "Lithium" rather than any BMS-managed option, then dial in your charge voltages manually (typically 54.4V bulk/absorption, 53.6V float for a 48V pack). Works a treat for my cabin setup running non-integrated cells.

@DailySolar is right about the BMS internals. Worth grabbing a cheap USB-to-UART cable and connecting directly to the BMS first — at least confirm it's actually alive and reporting correct cell voltages before you go down the CANbus rabbit hole.

Had a dodgy DALY in my static that showed nothing on the Victron side but was actually just in protection mode with a duff cell. Sorted once I could see what was happening internally.

If you want proper comms, Venus OS Large with a serial connection is your friend. Don't bother with the ZYC's claimed "Victron compatibility" — marketing fluff, that.