I have a Deye 6kW off-grid inverter and a Pylontech US3000C battery, and I’m struggling to get reliable communication between the two.

According to the manuals:

Pylontech:
- Pin 4 = CAN-H
- Pin 5 = CAN-L
- Pin 6 = CAN-GND

Deye:
- Pin 4 = CAN-H
- Pin 5 = CAN-L
- Pin 6 = BMS-GND / RS485-GND

So on paper, the pinouts seem compatible.

I bought the Greenrich/Pylontech to Sunsynk (Deye) CAN cable from GeeWiz, but that cable only uses pins 4 and 5 (CAN-H and CAN-L) and does not include a ground (pin 6).

From what I understand, CAN communication should theoretically work with just CAN-H and CAN-L, and some Deye documentation also suggests that only pins 4 and 5 are used. However, I’ve also seen cases where adding a ground connection (pin 6) or using a custom cable resolved communication issues completely

My question:

Do I actually need the ground (pin 6) for Deye ↔ Pylontech CAN communication, or should pins 4 and 5 be sufficient?

If anyone has a confirmed working cable pinout for this exact setup, I’d really appreciate it.

Edited April 20Apr 20 by TheOracle

Maybe I should just try a cable with GRN. Does anyone know where I can find someone to make me a custom cable in Pretoria East?

2 hours ago, TheOracle said:

Maybe I should just try a cable with GRN. Does anyone know where I can find someone to make me a custom cable in Pretoria East?

Before purchasing another CAN cable, strip a piece of network cable use one wire and back probe your existing cable pin 6 to pin 6 with the extra piece of wire check for continuity and see if it solves your comms problem. Then you could decide to purchase a cable with GND. Try Livestainable in Garsfontein Pta.

Livestainable.co.za

3m CAN BMS cable for Solis,sunsynk & Pylontech Lithium ba...

3m Can Bms Cable For Solis,Sunsynk & Pylontech Lithium Batteries

Edited April 20Apr 20 by TaliaB

1 hour ago, TaliaB said:

Before purchasing another CAN cable, strip a piece of network cable use one wire and back probe your existing cable pin 6 to pin 6 with the extra piece of wire check for continuity and see if it solves your comms problem. Then you could decide to purchase a cable with GND. Try Livestainable in Garsfontein Pta.

Livestainable.co.za

3m CAN BMS cable for Solis,sunsynk & Pylontech Lithium ba...

3m Can Bms Cable For Solis,Sunsynk & Pylontech Lithium Batteries

Thanks for the reply. Do you happen to know if the cable from Livestainable has a GND wire?

7 hours ago, TheOracle said:

Thanks for the reply. Do you happen to know if the cable from Livestainable has a GND wire?

Not sure but that said. I spoke to my brother in Gauteng and he installed a Deye 5kw with a Pylontech US3000C and this is the pinpouts he used with a cable made up by a pc technician.

Deye 5kw. Pylontech US3000C

Inverter 2 -> Pylontech 6

Inverter 4 -> Pylontech 4

Inverter 5 -> Pylontech 5

On 2026/04/20 at 7:11 PM, TaliaB said:

Not sure but that said. I spoke to my brother in Gauteng and he installed a Deye 5kw with a Pylontech US3000C and this is the pinpouts he used with a cable made up by a pc technician.

Deye 5kw. Pylontech US3000C

Inverter 2 -> Pylontech 6

Inverter 4 -> Pylontech 4

Inverter 5 -> Pylontech 5

I have made a cable with the pins as suggested by you, brother, but it is not working. I tested the cable with a cable tester to be sure.

The Deye battery type is set to Lithium and the Lithium mode is set to 0

Anything else I should check?