BSL Battery – Basic Troubleshooting Guide
Visual Inspection
Request close-up images of each battery unit if they haven’t already been provided. This helps with visual verification during remote diagnostics.
Verify Power Cable Connections
Examine the photos to ensure all power cables are securely connected. Keep in mind that the wiring setup may vary depending on how many batteries are stacked.
Check RS485 Communication Cables
Confirm that the RS485 cables are properly connected between each battery stack to allow for reliable communication.
Inspect DIP Switch Settings
Ensure that the DIP switches on each battery are correctly configured. DIP switches are used to assign a unique communication address to each battery and to designate one unit as the master in a multi-battery stack.
Understanding DIP Switch Settings in BSL Battery Stacks
Refer to the table below for the correct DIP switch configuration for each battery in a BSL stack system. This configuration ensures that each battery is uniquely addressed and properly identified by the BMS.
Important Note:
The battery at the bottom of the stack is considered Battery - 1 and functions as the Master Battery. From there, numbering continues upward—with Battery - 2 being the second from the bottom, and so on. DIP switch positions must be set accordingly to assign proper communication roles within the system.
Before adjusting any DIP switch settings, always follow this safety procedure:
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Turn off the main battery circuit breaker.
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(If needed) Hold down the reset button until the battery powers off completely.
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Ensure all batteries are fully OFF, then configure the DIP switches according to the required address settings.
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Turn the battery circuit breaker back ON to restore power.
Battery Check (for VICTRON, go to this link How to Check if Battery is Working)
1. Tap the battery icon on the main screen of the inverter interface.
2. Navigate to LIBMS on the lower right.
3. On the top right corner if you see “LIBMS: BSL BATT”.
- This confirms that communication with the BSL battery is active and functioning.
- Note: This display does not indicate how many batteries are connected.
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Refer to the Discharge Current Limit field.
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Each BSL battery supports a 100A discharge current.
Multiply 100A by the number of visible amps in the limit to estimate connected batteries.
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Example: If the discharge limit is 500A, you can infer ~5 batteries are connected.
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Caution: This is only an approximation. Discharge limits vary by battery type (e.g., Pylontech batteries may be 80A).
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Use this method as a quick diagnostic—if only 200A is shown when 5 batteries should be connected (500A expected), likely only 2 are properly connected.
To restore functionality and isolate the issue:
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Disconnect the suspected faulty battery from the stack.
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Reconfigure and restart the system using only the remaining batteries.
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If the system resumes normal operation, it is likely that the removed battery is the source of the fault.
This approach helps confirm the impact of the faulty unit and restores partial system function while awaiting replacement or service.
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Low Battery Voltage
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BMS Connection Lost
Upon inspection, it was discovered that the DIP switch on the 2nd battery had not been configured properly and the LED alarm indicator was also lit.
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