This can be caused by:
Incorrect Cell Population Settings
A Profile that has not been uploaded to the BMS (i.e. default profile on BMS)
Cell wiring harnesses not connected to the BMS
Cell tap wiring error
Voltages within a cell group are less than 10 volts
Internal damage to the BMS
Note: If the BMS has been damaged by previous wiring errors, do not continue to use the BMS. Contact Ewert Energy for evaluation and repair options.
Resolving the issue:
Step 1. Verify that the cell tap wiring harnesses are connected to the BMS and are plugged into the correct connectors.
Locate connector #1 on the BMS which is on the same physical end of the BMS as the total pack voltage sensor and ensure that the first wiring harness is connected in connector #1.
Step 2. Ensure that a profile has been uploaded to the BMS.
If no profile was uploaded to the BMS, the BMS does not know which cells are connected and defaults to assuming no cells are connected. Follow the steps in the “Profile Setup Wizard” to generate and upload a basic profile.
Step 3. Verify that cells have been properly populated.
In the utility ensure that the profile is downloaded from the BMS by clicking “receive current profile from BMS.” Under the “Cell Settings” tab, click the “Cell Population Settings” button. Ensure that cells which are connected have a check in the “Populated” box. If changes were made, the profile will need to be sent to the BMS by clicking the “Send Profile Changes to BMS”.
Step 4. Using a multimeter, measure cell voltages and ensure that the total voltage in each cell group is at least 10 volts.
Each cell group must have a sum of at least 10 volts for cell voltages to appear.
Step 5. Test the cell tap wiring either using a multimeter or preferably the cell validation tool.
Step 6. Contact Ewert Energy for an evaluation of the BMS unit as there may be internal damage.
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