Physical CAN/RS485 Wiring & Inverter-Side Setup


Selecting the protocol in the JK App is only half the battle. For your AmpBox to properly “handshake” with your inverter, the physical wiring must match the inverter’s expected pinout. Different inverter brands use different data lanes, so a standard Ethernet cable doesn’t always work.

1. The RJ45 Pinout Challenge

The JK‑PB2A16S uses a standard CAN pinout, but many inverters (like Victron or SMA) expect CAN‑High and CAN‑Low on different pins. This is why a “normal” Ethernet cable may not work.

Inverter Brand Connection Type Required Cable
Deye / Sol‑Ark / Luxpower CAN Straight‑Through CAT5/6
Victron (Cerbo GX) CAN Type A/B Blue Cable (Pins 7 & 8)
Growatt SPF Series RS485 Specific RS485 Pinout (Check Manual)
EG4 / Schneider CAN Straight‑Through CAT5/6

Pro Tip: If your inverter did not include a “BMS Cable,” you may need to crimp a custom RJ45 cable so that CAN‑High and CAN‑Low match the inverter’s required pins.

2. Inverter‑Side Configuration

Once the cable is connected, you must tell your inverter to stop reading voltage and start listening to the AmpBox BMS.

For Deye / Sol‑Ark:

  • Go to Battery Setup → Batt Mode.
  • Select Lithium.
  • Set Lithium Mode to 00 or Pylontech.
  • Communication icon should turn from Red “X” to Green checkmark.

For Victron Energy (Cerbo GX / Venus OS):

  • Go to Settings → Services → VE.Can Port.
  • Set Baud Rate to 500 kbit/s.
  • The “JK‑BMS” or “Pylontech Battery” should auto‑appear in the Device List.
  • Ensure DVCC is forced ON to allow charge‑current control.
3. Setting the Baud Rate

If you are using RS485 instead of CAN (common for older Growatt or Voltronic units), the baud rate must match on both devices.

  • Open the JK BMS App → Settings.
  • Find RS485 Baud Rate.
  • Standard speeds: 9600 or 19200.
4. Troubleshooting the Handshake

If the inverter shows BMS Error or “Communication Loss”:

  • The Master Rule: Ensure the AmpBox you’re plugged into has DIP Switch #1 ON. Some inverters require the battery to identify as Address 1.
  • Port Swap: If RS485‑1 doesn’t work, try RS485‑2. One port is often reserved for battery‑to‑battery communication.
  • Termination: On long cable runs, add a 120Ω CAN termination resistor to the empty port of the last battery in the chain.

Summary: Hardware communication comes down to the Pipe (the cable) and the Speed (baud rate). If the pinout matches and the baud rate is correct, the data will flow reliably.

Next Step: Continue to Article 3.3: Multi‑AmpBox Parallel Configuration if you plan to expand your storage system.

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