Pylontech Power on Sequence
Pylontech Power-On Procedure (Startup Sequence)
Use this step-by-step Pylontech power-on procedure for DIY and installer setups using Pylontech US2000 / US3000 / US5000 (single battery or stacked systems). Correct startup order prevents many issues such as no communication, protect mode, and inverter BMS faults.
Tip: Always power the battery first, then the inverter/charger. Powering the inverter before the battery is a common cause of communication faults.
Step 1 – Turn off all devices
- DC breaker between battery and inverter is OFF
- AC input, AC output, and PV/Solar DC to the inverter are OFF
- Correct communication cable is connected (CAN or RS485)
- If multiple batteries are installed:
- Master battery selection is correct
- DIP switches are set as per the Pylontech manual
- Link cables are connected in the correct order
Step 2 – Power on the battery stack
- Turn on all batteries using the power switch to the ON position. If any SOC LEDs are already lit on any battery, there is still DC present (for example, the inverter DC bus capacitors may still be charged or a battery is still on). If this happens, go back to Step 1 and wait for the system to fully power down.
- On the master battery only, press and hold the red SW POWER button for ~1 second, then release.
- You should see the SOC LEDs come on and flash once.
- You should then see SOC LEDs initialise on each slave battery in turn. If it skips a slave, check that battery is switched on, check the link/comms cables are connected correctly, and check the DIP switch settings. If issues continue, move the suspect slave to the end of the stack for testing.
- Wait 30 seconds for the battery stack to initialise.
Step 3 – Enable DC to the inverter
- Turn ON the DC breaker between the battery and inverter.
- Wait 10–20 seconds. If the inverter starts up, continue to the next step. Some inverters also require AC supply to be present before they will fully boot.
- Confirm the inverter sees valid BMS communications, not just battery voltage. For example, seeing only a DC voltage (e.g. 49.87V) is not proof of comms. You should also see values derived from BMS comms such as SOC % (state of charge), charge/discharge current, and/or a requested charge voltage (e.g. 53.2V).
Step 4 – Power on the inverter
- Power on the inverter/charger (follow manufacturer guidance).
- Allow the inverter to fully boot.
- Confirm battery comms is working:
- Battery detected
- SOC visible
- No BMS/communication errors
Final checks
- No ALARM / protect LEDs on the battery
- Inverter shows SOC and current (charge/discharge)
- System behaves normally before enabling AC loads and PV charging
If you get a fault (reset & retry)
If you see any of the following: no communication, protect mode, inverter BMS faults, or Error 61 (Axpert/Voltronic), perform a full shutdown and repeat the sequence exactly.
Full power cycle procedure
- Turn the inverter OFF
- Turn the DC breaker OFF
- Turn the battery OFF
- Wait 60 seconds (do not power-cycle rapidly)
- Restart from Step 1 above
Common mistakes
- Powering the inverter before the battery
- Incorrect CAN/RS485 cable pinout
- Not waiting long enough between steps
- Incorrect master/DIP configuration on stacked batteries
Need help?
If you’re still stuck, include your battery model, inverter model, whether you are using CAN or RS485, and photos of the comms ports/labels.
Disclaimer: This guide is general advice for common setups. Always follow the latest official Pylontech manuals and qualified installer advice where required.