Pylontech Batteries Not Communicating? Check Your Power-On Sequence First
One of the most common causes of issues with Pylontech US2000, US3000, and US5000 batteries is an incorrect startup order.
We regularly see DIY systems reported as:
- “Battery not communicating”
- “BMS fault / Error 61”
- “Battery stuck in protect mode”
- “SOC not showing on the inverter”
In many cases, the hardware is fine — the problem is simply that the inverter was powered before the battery, or the battery stack wasn’t allowed to initialise correctly.
Pylontech batteries use an internal BMS that expects a specific startup sequence. If this sequence isn’t followed, the BMS may not establish communication properly, which can lead to faults, missing data, or the system refusing to operate.
To help avoid this, we’ve published a clear, step-by-step guide covering:
- Single and stacked battery systems
- Correct master/slave startup behaviour
- What the LEDs should do during startup
- How to confirm real BMS communication (not just DC voltage)
- How to safely reset and retry if something goes wrong
👉 Read the full guide here:
Pylontech Power-On Procedure (Startup Sequence)
Following the correct power-on sequence before changing cables, settings, or firmware can save a lot of time — and avoid unnecessary fault chasing.
If you’re still having issues after following the procedure, include your battery model, inverter model, and whether you’re using CAN or RS485 when contacting support.