Pylontech battery, cerbo-gx pylontech

Been down this exact rabbit hole recently with my static caravan setup, so thought I'd share what I found in case others are pulling their hair out.

Running a Victron Cerbo GX, MultiPlus-II 48/5000, and SmartSolar MPPT 150/35 with a pair of Pylontech US3000C batteries. The Cerbo picked up the MultiPlus and MPPT without any drama over VE.Bus and VE.Direct respectively — all showing cleanly in VRM within minutes.

The sticking point was getting the Pylontech to talk properly over CAN-bus. The official Pylontech cable (the 5WRPY01 series) connects from the A/CAN port on the master battery to the VE.Can port on the Cerbo. What tripped me up initially was the termination resistor — the VE.Can network needs 120Ω termination at both ends, and the Cerbo's port isn't self-terminating by default. Once I fitted the Victron VE.Can RJ45 terminator on the open port, the battery appeared immediately in the Cerbo device list and DVCC kicked in properly.

A couple of things worth checking if yours isn't showing:

• BMS cable pinout — Pylontech's own cable is wired correctly for Victron, but third-party alternatives sometimes aren't
• CAN profile — make sure VE.Can is set to 500 kbit/s (Pylontech) under Cerbo settings, not the default 250 kbit/s
• Firmware — update both Cerbo and Pylontech BMS before troublesho

@Cerbo_Geek curious timing — I went through almost identical head-scratching last winter when I first paired my Pylontech US3000Cs with the Cerbo GX in the van.

The bit that caught me out was the DVCC settings. Once Pylontech is detected via the VE.Can port, you must let the BMS have charge control authority — fighting it with manual charge voltage overrides in the MultiPlus will cause all sorts of odd behaviour. Victron's own documentation is oddly vague on this.

Worth checking in VRM portal whether your Pylontech is actually broadcasting correctly — mine showed as "unknown battery" for two days before I realised I'd used a standard RJ45 rather than the specific Pylontech comms cable pinout.

What firmware are you running on the Cerbo? There were some known quirks pre-v3.00 with Pylontech recognition.

The Cerbo GX talks to Pylontech via RS485 using the VE.Can to RS485 cable — make sure you've set the battery monitor to "Pylontech" in Venus OS settings or it'll just sit there looking confused like my ex at an IKEA flat-pack.

Key things to check:

• DVCC enabled (Device menu → System setup)
• Pylontech BMS becomes the charge master once it's communicating properly
• Set Venus OS to 2.80+ minimum for reliable Pylontech comms

@KentVanLifer is right that the initial pairing can be maddening — the RS485 termination resistor catches everyone out at least once.

Also worth knowing: Victron's own VRM portal will show the Pylontech cell data once comms are solid, which is genuinely brilliant for peace of mind on a static setup.

@Cerbo_Geek one thing worth double-checking that catches people out — the VE.Can termination resistors. Both ends of the CAN bus need to be terminated (120 ohm), and the Cerbo GX has a physical jumper for this, not just a software setting. Easy to miss.

Also, in VictronConnect/VEConfigure make sure your MultiPlus-II charge parameters aren't overriding what the BMS is requesting via DVCC. If DVCC is enabled (which it should be with Pylontech), the battery essentially takes control of charge/discharge limits — but only if SVS and SCS are ticked correctly under the DVCC settings in Remote Console.

Got this wrong myself initially on my static caravan install and couldn't understand why the batteries weren't hitting full capacity. Took an embarrassingly long time to spot.

Great thread — @MarineGeoff and @BayJason have covered the cable and termination bits, so I'll add what caught me out specifically with Pylontech on Cerbo GX.

In VictronConnect / Remote Console, make sure your DVCC settings are properly configured:

• DVCC: ON
• SVS (Shared Voltage Sense): ON
• SCS (Shared Current Sense): ON
• Limit charge current: let the Pylontech BMS dictate this via CAN, don't override it manually

The Pylontech BMS will send charge voltage and current limits automatically once comms are established — if you've hardcoded values in the MultiPlus-II itself via VEConfigure, those can conflict horribly and you'll see weird charge behaviour.

Also worth checking: firmware on the Pylontech units needs to match across your stack if you're running multiple batteries. Mismatched firmware causes the BMS to report odd SOC figures in the GX console. Ask me how I know... 🤦