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Pylontech Error Codes

Expert reference guide covering all Pylontech battery diagnostic codes with comprehensive troubleshooting procedures and professional repair guidance

Quickly identify problems with your Pylontech battery system and learn the correct response procedures

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Pylontech Battery Models

Pylontech produces an extensive lineup of premium battery storage systems for residential and commercial solar installations. The US2000, US3000, and Force H2 series represent high-quality lithium-ion battery storage solutions with advanced battery management systems. These diagnostic codes are applicable to the majority of Pylontech battery systems sold in the United States. Error indicators typically manifest as numeric error codes (e.g., 60, 71, 72, 80-86), LED blink patterns on ALM (alarm) LEDs, and status messages in the monitoring system. Error codes are displayed through LED sequences and system communication.

How to Read Error Codes

• Check ALM LED blink patterns (1, 2, 5, 15 blinks)
• Review numeric error codes (60, 71, 72, 80-86)
• Check battery LED status indicators
• Review monitoring system for status messages
• Consult Pylontech documentation for your specific model
• Master battery has red SW button for reset

Pylontech Product Series

• US2000 - 2.4 kWh battery modules
• US3000 - 3.5 kWh battery modules
• Force H2 - High-capacity battery systems
• Advanced battery management system
• CAN bus communication

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Understanding Diagnostic Codes

Pylontech battery systems incorporate sophisticated diagnostic capabilities that automatically detect operational issues. When a problem is identified, the system communicates through numeric error codes (e.g., 60, 71, 72, 80-86), LED blink patterns on ALM (alarm) LEDs, and status messages in the monitoring system. This intelligent diagnostic framework enables rapid problem identification and helps determine the appropriate response. All Pylontech battery series utilize continuous performance monitoring with real-time error detection. LED blink patterns indicate specific errors: 1 blink (short circuit), 2 blinks (overcurrent discharge), 5 blinks (cell/module undervoltage), 15 blinks (system error), and continuously blinking (communication error). Always reference your specific system's documentation for precise code definitions.

Communication and System Errors

Problems with battery communication and system configuration.

Code	Meaning	Possible Causes	Solutions
80	CAN Bus Communication Error - Communication error in CAN bus between battery and inverter	•CAN bus wire break •Battery not responding •CAN bus failure •Inverter communication issue •Firmware incompatibility	Check CAN bus wiring between battery and inverter Verify battery is properly connected Check battery LED status indicators Restart battery system by turning off all modules and waiting 10-20 seconds Press and hold red SW button on master battery for 1 second Verify inverter and battery firmware compatibility Check for loose or damaged CAN bus cables Contact Pylontech support if communication cannot be restored
81	Connection Error - General connection error between battery and other system components	•Connection wire break •Battery not responding •Connection failure •Inverter connection issue •Module connection error	Check all connection wiring between battery and inverter Verify battery is properly connected Check battery LED status indicators Restart battery system Verify all module connections are secure Check for loose or damaged connection cables Contact installer if connection cannot be restored
82	Synchronization Loss - Synchronization between battery and system is lost	•Synchronization failure •System configuration error •Communication interruption •Firmware mismatch •Module synchronization error	Restart battery system by turning off all modules Wait 10-20 seconds Turn all module switches back on Press and hold red SW button on master battery Verify system configuration Check firmware compatibility Contact installer if synchronization cannot be restored
71	Firmware Version Not Compatible - Battery firmware version is not compatible with system	•Firmware version mismatch •Incompatible firmware versions •Firmware update required •System firmware incompatibility	Check firmware versions of battery and inverter Update battery firmware to compatible version Update inverter firmware if necessary Verify firmware compatibility list Contact Pylontech support for firmware update assistance Do not mix incompatible firmware versions
ALM LED Continuously Blinking	Communication Error - System error or communication error with other batteries	•Communication wire break •Module communication failure •CAN bus error •System communication error	Check communication cables for proper seating and damage Verify correct communication protocols and settings are used Restart battery system Check module LED status indicators Verify all modules are communicating Contact installer if communication cannot be restored

Battery and Charging Errors

Problems with battery cells, charging, and discharging.

Code	Meaning	Possible Causes	Solutions
60	Feedback Protection - Battery status prevents charging and discharging after successful communication	•Battery protection activated •Battery status issue •System protection •Battery management system error	Check battery status and state of charge Verify battery is not in protection mode Restart battery system Check battery management system status Contact installer if protection cannot be cleared
72	Current Sharing Error - Problem with current distribution within system	•Current sharing circuit failure •Module current imbalance •Current distribution error •Battery management system error	Check current sharing between modules Verify all modules are functioning correctly Check module connections Restart battery system Contact installer if current sharing cannot be restored
83	Battery Voltage Different Detected - Different voltage values detected within battery system	•Module voltage imbalance •Cell voltage imbalance •Battery cell failure •Module failure •Voltage measurement error	Check individual module voltages Verify module voltages are balanced Check for faulty modules Allow battery management system to balance voltages Contact installer if voltage imbalance persists May require module replacement
5 Blinking ALM LEDs	Cell or Module Undervoltage - One or more cells or modules have too low voltage	•Deep discharge •Cell failure •Module failure •Battery not used for extended period •System fault	Charge battery to increase voltage Check cell voltages Replace defective modules if necessary Avoid deep discharge cycles Contact installer if voltage remains low after charging This may require module replacement
Battery Overvoltage	Battery voltage exceeds maximum limit	•Overcharging •Battery cell imbalance •Charging system fault •Battery management system error •Cell failure	Stop charging immediately Check battery voltage with multimeter Verify charging system is functioning correctly Check for battery cell imbalance Contact Pylontech support immediately Do not attempt to discharge if voltage is critically high This may require battery service or replacement
Battery Undervoltage	Battery voltage below minimum threshold	•Deep discharge •Battery not used for extended period •System fault •Battery cell imbalance •Discharging system fault	Stop discharging immediately Check battery voltage with multimeter Begin charging if safe to do so Check for battery cell imbalance Contact Pylontech support if voltage is critically low Avoid deep discharge cycles This may require battery service or replacement

Overcurrent and Protection Errors

Problems with overcurrent protection and discharge limits.

Code	Meaning	Possible Causes	Solutions
1 Blinking ALM LED	Overcurrent Discharge - Short circuit protection	•Short circuit in wiring •Reversed polarity •High discharge current •Faulty load •Wiring error	Check wiring for short circuits or reversed polarity Remove current load and test with different device Ensure no metal parts are grounded that touch positive pole Check all connections for proper polarity Verify load is within battery specifications Contact installer if problem persists
2 Blinking ALM LEDs	Overcurrent Discharge - Protection against excessively high current discharge	•Excessively high discharge current •Load exceeds battery capacity •Faulty load •System overload	Reduce load to within battery specifications Check load current requirements Verify load is compatible with battery Remove excessive load Check for faulty load devices Contact installer if problem persists

AC Grid and System Errors

Problems with AC grid connection and system configuration.

Code	Meaning	Possible Causes	Solutions
84	AC Input Voltage and Frequency Different Detected - Deviations in AC input voltage and frequency detected	•Grid voltage fluctuations •Grid frequency fluctuations •Grid instability •Grid quality issues •Voltage measurement error	Check grid voltage and frequency with multimeter Verify voltage and frequency are within allowable limits Wait for grid to stabilize Contact utility company if voltage/frequency is consistently out of range System will automatically reconnect when grid stabilizes Contact installer if problem persists
85	AC Output Current Asymmetry - Uneven AC output current detected	•AC output current imbalance •Load imbalance •Inverter fault •System configuration error	Check AC output current balance Verify load distribution Check inverter operation Review system configuration Contact installer if current asymmetry persists
86	AC Output Mode Setting Different - Different AC output mode settings detected	•Configuration mismatch •System configuration error •Settings not synchronized •Firmware issue	Check AC output mode settings Verify all modules have same settings Synchronize system settings Review system configuration Contact installer if settings cannot be synchronized

Hardware and Internal Errors

Problems with battery internal systems and hardware components.

Code	Meaning	Possible Causes	Solutions
15 Blinking ALM LEDs	System Error - General system error detected	•System fault •Internal error •Battery management system error •General system malfunction	Restart battery system by turning off all modules Wait 10-20 seconds Turn all module switches back on Press and hold red SW button on master battery If error persists, contact Pylontech support Do not repeatedly restart if error continues May require professional diagnosis and repair
Internal Battery Error	Internal battery fault or hardware error	•Internal battery fault •Control board issue •Hardware failure •Component malfunction	Restart battery system If error persists, contact Pylontech support Do not repeatedly restart if error continues Note error details and contact certified installer May require battery replacement or repair
Module Failure	Battery module failure detected	•Module hardware failure •Module cell failure •Module communication failure •Module control board issue	Identify which module has failed Check module LED status indicators Contact Pylontech support immediately This requires professional diagnosis Module may need replacement Do not attempt to repair yourself

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Critical Safety Notice

Do not attempt DIY repairs on your Pylontech battery system. The majority of diagnostic codes relate to high-voltage battery systems, battery management systems, or critical safety features. Specific codes requiring immediate professional intervention include: Battery Overvoltage, Battery Undervoltage, Overcurrent Discharge (1-2 blinking ALM LEDs), and Module Failure. Upon encountering these codes, immediately shut down the system if safe to do so and contact a certified Pylontech installer or service without delay.

Professional service is mandatory—contact a licensed solar installer or reach out to Pylontech technical support for expert assistance.

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Battery Reset Procedure

A reset can help resolve communication errors or restore functionality. Follow these steps to reset your Pylontech battery system:

1
Turn off inverter and all battery modules
Turn off the inverter. Turn off all toggle switches on the left side of each battery module.
2
Wait and turn modules back on
Wait 10 to 20 seconds. Turn all toggle switches back on.
3
Press SW button on master battery
Identify the master battery (connected to inverter). Press and hold the red SW button on the front of the master battery for 1 second until all LEDs light up.
4
Verify system operation
Observe LED indicators; a successful reset restores normal LED pattern. Turn the inverter back on.

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Maintenance Guidelines

Scheduled Service Requirements

✓Professional inspection and service annually by certified Pylontech installer
✓Monthly visual inspection of battery modules for damage or issues
✓Monitor system performance daily through monitoring system
✓Check battery status and LED indicators monthly
✓Verify CAN bus communication monthly
✓Check battery temperature and ventilation quarterly

Proactive Maintenance Strategies

✓Ensure adequate ventilation around battery modules
✓Keep battery in temperature-controlled environment
✓Monitor battery state of charge and health
✓Review system alerts and error codes promptly
✓Keep firmware updated for latest features and fixes
✓Inspect CAN bus wiring for damage or corrosion

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Frequently Asked Questions

What does error code 80 (CAN Bus Communication Error) mean?

Error code 80 indicates a communication error in the CAN bus between battery and inverter. Check CAN bus wiring, verify battery is properly connected, check battery LED status indicators, restart battery system by turning off all modules and waiting 10-20 seconds, press and hold red SW button on master battery, verify firmware compatibility, check for loose or damaged CAN bus cables, and contact Pylontech support if communication cannot be restored.

What does 1 blinking ALM LED (Overcurrent Discharge) mean?

1 blinking ALM LED indicates overcurrent discharge due to short circuit protection. Check wiring for short circuits or reversed polarity, remove current load and test with different device, ensure no metal parts are grounded that touch positive pole, check all connections for proper polarity, verify load is within battery specifications, and contact installer if problem persists.

What does 5 blinking ALM LEDs (Cell/Module Undervoltage) mean?

5 blinking ALM LEDs indicate that one or more cells or modules have too low voltage. Charge battery to increase voltage, check cell voltages, replace defective modules if necessary, avoid deep discharge cycles, contact installer if voltage remains low after charging, and this may require module replacement.

How do I reset my Pylontech battery system?

To reset your Pylontech battery system: 1) Turn off inverter and all battery module switches, 2) Wait 10-20 seconds, 3) Turn all module switches back on, 4) Press and hold red SW button on master battery for 1 second until all LEDs light up, 5) Verify system operation by observing LED indicators, then turn inverter back on.

What does error code 71 (Firmware Version Not Compatible) mean?

Error code 71 indicates that the battery firmware version is not compatible with the system. Check firmware versions of battery and inverter, update battery firmware to compatible version, update inverter firmware if necessary, verify firmware compatibility list, contact Pylontech support for firmware update assistance, and do not mix incompatible firmware versions.

Can I repair my Pylontech battery system myself?

High-voltage battery systems must exclusively be serviced by licensed professionals to ensure safety compliance. Homeowners can safely perform basic tasks like monitoring the system and checking LED indicators, but all technical repairs require certified Pylontech installers. Unauthorized work on battery systems poses extreme danger and violates building codes.

What should I do if I see "Internal Error" in my monitoring system?

Internal Error can occur when individual modules shut down at low state of charge (SOC) and stop communication. This behavior has been observed at SOC below 15%. Try resetting the battery system, check module SOC levels, ensure all modules are charging, and contact installer if error persists.

How often should I check my battery system?

Monitor your battery system daily through the monitoring system, check battery status and LED indicators monthly, verify CAN bus communication monthly, and perform professional inspection and service annually by a certified Pylontech installer. Review system alerts and error codes promptly.

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Need Additional Help?

Search our complete knowledge base to find detailed solutions for your specific problem.

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Summary

Proper interpretation of diagnostic codes is essential for effective Pylontech battery system troubleshooting. This comprehensive reference enables quick problem identification and guides appropriate response actions. Pylontech systems utilize numeric error codes (60, 71, 72, 80-86), LED blink patterns on ALM LEDs (1, 2, 5, 15 blinks), and status messages in the monitoring system to indicate specific sensor and system malfunctions. US2000, US3000, and Force H2 series battery systems provide diagnostic information through error codes and LED indicators for convenient diagnosis.

⚠️Complex diagnostic situations, especially those involving high-voltage battery systems, battery management systems, and overcurrent protection, require immediate professional evaluation. Critical codes demanding urgent response include: Battery Overvoltage, Battery Undervoltage, Overcurrent Discharge (1-2 blinking ALM LEDs), and Module Failure. These indicators represent serious safety hazards requiring certified Pylontech installer response. Adherence to scheduled maintenance protocols and immediate attention to diagnostic codes extends equipment service life and minimizes long-term operational costs. Note that error code formats may vary by model and firmware version—always consult your specific system's installation and service manual for precise interpretations.