daveh-1 avatar image
daveh-1 asked

Pylontech RT12100G31 Installation and Integration with Victron CCGX

I have recently installed 8 x Pylontech RT12100G31 as a single 800ah 12v battery bank. The batteries are working (charging and discharging) and are interlinked for balancing. They show up correctly as a single bank in the Pylontech bluetooth app.

However, I have not been able to get the batteries to communicate with the CCGX. The CCGX is on the latest firmware (v2.92) and I have have a victron terminator in the other VE.Can port.

There is very limited information about these batteries online and unfortunately the instruction manual is very limited. I have used the following links for reference:

I have wired the comms cable using the type B Pinout in the first link above as this matches the batteries instruction manual as below. I have tested the wires in the cables pin to pin to confirm continuity and correct pin matching. This has proven correct ... multiple times. I have also removed the VE-Can terminator and confirmed it has continuity and resistance of 120 ohms between Pins 7 & 8.


The table above shows Pin 7/8 being for RS485A /B. I have not wired this as it does not seem to map to any wire in the Victron VE CAN-bus RJ45 terminator and I know others with working integration between the same pylontech batteries and a Cerbo without this wired.

The documentation suggests that once correctly connected, configuration will occur automatically, but I have also tried manually turning on DVCC and configuring the VE CAN-Bus profile. I have tried all available profiles without success although I believe the correct one should be Can-bus BMS (500kbit/s).

Has anyone succesfully connected these batteries to a CCGX and can advise on what I could have wrong? Alternatively, perhaps someone with experience in connecting a BMS to CCGX can help?

BMSCCGX Color ControlPylontechVE.Canknowledge base
20230212-132010.jpg (32.4 KiB)
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kevgermany avatar image kevgermany ♦♦ commented ·

Just to confirm - did you use type B or type A to get this working?

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Mark avatar image Mark kevgermany ♦♦ commented ·

a Standard cat5 cable will work,as you have to terminate it yourself into the generic Pylontech Can connector

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5 Answers
Alexandra avatar image
Alexandra answered ·


Since it is not listed as an official supported battery, some experiments will be needed. I have not used them personally.

A couple of things though, did you use the can terminator?

Have you tried the type A cable? According to this sales speel that is the cable used.

Really the only difference between type a and b is the ground.

Try it with just one module first, then connect the whole bank.

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daveh-1 avatar image daveh-1 commented ·
Thanks for the suggestions. I do have a terminator in place and I have also tried Type A by moving the ground pin from 2 to pin 6 without any luck. Pylontech terminate to a non-RJ45 cable in the battery so I made my own cable locally and assumed type B was correct as manual says the ground should be in the battery terminal Pin 2. Thanks again for your help, I'm definitely open to any other ideas.
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daveh-1 avatar image
daveh-1 answered ·

Problem resolved, amateur mistake I'm afraid but I'm leaving the main post without further edits in case it helps others. The pinouts provided in the manual are looking face onto the pins, not the way the wires are screwed into the rear, swapping them around resolved the issue quickly.

For anyone else looking to do this, as soon as the wiring was corrected the battery bank showed up automatically. The Vitron CCGX recognised the pylontech batteries as a device and DVCC settings changed to "Forced on". The SoC updated to match that of the Pylontech app and the following information was provided:



Another good resource I found was:

The correct VE-Can profile was definitely: Can-bus BMS (500kbit/s)

To help anyone thinking of buying these batteries, the standard box of one battery comes complete with:

- instruction manual, attached:Batteries - Pylontech RT12100G31 - Operating Manual.pdf

- A 0.3m battery interlinking cable (comms not power) to link to the next battery in your bank. The cable comes out the top of the connectors at right angles and can be orientated in the direction to best suit the required run of the wire. If you purchase more than one battery and they are not going to be right next to each other, you will need to purchase longer cables. This cable allows the bms of the batteries to comminicate to other batteries in your bank for self balancing and ultimately to allow the master battery to pass on information for the entire bank via the comms cable to a Victron GX device of via bluetooth to the Pylontech app (see attached manual: Batteries - Pylontech RT12100G31 - Bluetooth.pdf

- A connector for a comms cable to the victon GX. This is a simple screw in connector requiring no soldering, crimping or heat shrinking. You can purchase a standard LAN cablem chop of one end and wire the provided connector onto this end, plugging the other RJ45 into the GX device. Unless your GX device has a VE-BMS port, you will need to put this RJ45 into the VE-Can port and if the other port is empty, install a Victron VE-Can terminator in it.

- A connector to put into the I/O port if you want to use the heat function. This requires no cable.

As usual with other batteries, there are no power cables to link to other batteries in the bank or to an invertor.

The battery terminals are an M8 bolt (Metric 8mm diameter). HOWEVER, the thread on the bolt is very fine, I believe it is M8 x 1.0. If you want to install screw in battery terminals you are unlikely to fine the correct thread in the US and may even struggle in other places as the standard thread is usually the courser M8 x 1.25. The provided bolts are also not very long, only 13mm of thread up to the washer + spring washer which are not removeable (without cutting them). If you are using large diameter electrical wire with large ring terminals, you may struggle to easily fit them onto the bolts, particularly if your access to the batteries is tight.

Hopefully this info helps others looking to install these batteries.

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cesar avatar image cesar commented ·
Hi @DaveH , I have bought the same pylontech battery for my system, I haven't connected yet because I have read that it is dangerous to use lithium battery without integrating the BMS, but I just saw you have used your battery without integration for some time. Is it really dangerous to do it without the integration?
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daveh-1 avatar image daveh-1 cesar commented ·

Hi @Cesar

The important thing to note about these batteries is that each has its own BMS which will independently stop charging and/or discharging if they exceed the batteries capacity. Yes, I briefly used the batteries without them being connected to my Victron CCGX but I was not connected to shore power and had changed the solar MPPT settings updated to Lithium charging. I also still had my victron battery monitor and shunt in place measuring voltage and current. Whilst my alternators were still connected to the batteries, my engine use was very limited.

I am certainly happier now the batteries are successfully connected to the ccgx but I could have managed without if needed. On my boat, I also disconnected the boats built in shore power AC to DC chargers from the Pylontechs and updated the firmware on my victron invertor charger. The outcome is that I now have solar and shore power charging and 220v AC discharging being controlled by the pylontech BMS.

The only thing I will look to improve further in the future is the alternator to battery setup. However, with thermally limited low power alternators, they will not overheat, are highly unlikely to be able to provide too much charge and if they did, the pylontech BMS will stop accepting charge.

Ultimately, you need to fully understand your charging and discharging system and your usage and use these to make an informed decision. If you don't understand them, don't risk it.

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Herve RV Nizard avatar image
Herve RV Nizard answered ·

Thanks for all these details @DaveH . We have ordered some for some 12 v systems and look forward to receiving and installing them with Victron . Your detailed posts do help a lot. I was about to post on the subject asking if the RT12100 could be seen on GX , and take-over as the UP5000 are and do. Thanks .

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dj-dulux avatar image
dj-dulux answered ·

Thanks for the great info @DaveH, I have just bought 10 (2S5P 24V@500Ah) of these and was wondering what the CCL and DCL limits are coming from the BMS to Victron? Could you have a quick look please, I think for your 800Ah bank it sould be around 400A, but historcally Pylontech (and BYD) reduce the adversised CCL a bit?

@Herve RV Nizard did you get up and running OK with yours?

Are either of you using DC-DC or alternator to charge too, I am looking at setting up the Mastervolt regulator to charge them too, sent mail to Pylontech about charge profiles and voltage etc, just waiting for reply?



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lee-taylor avatar image
lee-taylor answered ·

@daveh-1 Another thanks for this info. I have a 12V system as a backup for my heating currently running of a Renogy 200Ah battery, but I dont like the idea of using an internal BMS so have purchased one of the Pylontech 12V batteries. I dont use a Cerbo GX on this setup, its controlled with a raspberry pi-4 running Venus, but I have fitted a Waveshare isolated Can hat which I have confirmed working when hooked up to my 48V system.

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lee-taylor avatar image lee-taylor commented ·
Just as a follow on to this. The battery turned up yesterday and I couldn't get it to connect to my raspberry pi via the two channel waveshare hat. I wasted hours on this with different wiring connections, uninstalling the hat and reinstalling it before finally finding that it connected on the second channel......sigh.
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