First start-up
This page will explain some start-up messages, what to do when first using the BMS
First start-up messages
When first starting the BMS with the latest software the command line interface could look like the code snipping at the end of the page.
You can see that the version number is: bms4.0-10.1. this comes after "BMS version: ".
Than it will begin doing self-tests.
START means it will start testing that part or component
PASS means that the test succeeded
FAIL means the test did not succeed
Be sure to check the error messages as it could help finding out what is wrong, some errors explain why it went wrong and how you could fix it.
It could be that you will get these messages:
These messages mean that the CRC of the saved data (the parameters) in flash doesn't match. This could happen when nothing is saved or when a new program is flashed in the microcontroller (and thus cleared the flash).
Than it could be that you get the message "NVMS registers don't have the right value!". This means a register in the SBC needs to be written, but before this could take effect, it needs to restart the SBC, "Restarting!" is stated when it does this. Since the SBC supplies the microcontroller with its power, the microcontroller will restart as well.
It could be that you get the message that the stackvoltage is too different from sum of cells, so there is a wrong n_cells number. This means that the actual connected cells are different than the entered number of cells (n-cells). To fix this, check what the current n-cells value is with "bms get n-cells" and make sure it corresponds with the number of cells in the attached battery. To configure the correct number of cells type "bms set n-cells x" where x the number of cells of the battery, that can be 3-6. After that type "bms reset" or press the button to reset the fault. In version 3.4 there is something wrong, n_cells should be n-cells.
You will get a warning if the battery temperature sensor is not enabled, "WARNING: battery temperature sensor is disabled!". To enable the battery temperature sensor see .
If you see the text that the BCC overvoltage set to <number>mV. That number should be slightly higher than the actual set cell-ov in the software. This is because the overvoltage threshold register of the BCC is an 8-bit register, compared to the floating point variable in the software this has a lot less resolution. The value in the BCC is set slightly higher to not falsely trigger on it, but have it as a backup trigger since the software will react on the overvoltage as well with the measured cell voltage.
It could be that you see the following line: "NOTICE: Disabling 5V regulator (CAN transceiver) briefly!". This happens when the SBC needs to switch modes, because it can only be done in the standby mode where the 5V regulator is disabled.
"BMS main loop!" means the BMS has entered the main loop and will continue according to the main state diagram.
Each time the BMS enters a new mode, it will output this with "<mode> mode"
first time software configuration of the BMS
It is highly recommended that you check each parameters in and make sure to configure each parameter. Use "bms get all" to get each parameter and it's value, so you could configure each one for your battery.
Some parameters you would like to configure are:
a-rem (the remaining capacity)
the BMS does a guess on what the remaining charge is based on a OCV(open cell voltage)/SoC (state of charge) table from one specific battery, but every battery is different.
It is advisable to insert the correct OCV/SoC table for the battery.