Amending BMS Parameters to Prevent High Cell Voltage warnings / DVCC Set Up
This article will guide you through the process of amending your SMART4 BMS parameters and DVCC charge voltage settings to prevent High Cell Voltage warnings.
Firstly, turn on DVCC, toggle on 'Limit managed battery charge voltage' and set this to 14.2V [28.4V]* (average cell voltage 3.55V). You should then complete a few cycles (fully discharge and charge) if not already done so. The active balancer inside the battery will have balanced the cells very closely, meaning all cell voltages are staying below the 3.60V threshold. This is a good thing, but it does mean some changes are needed if you want the battery to calibrate correctly going forwards.
If the 'High Cell Voltage warning' stops, you can try increasing the DVCC charge voltage limit back to 14.4V [28.8V]*. This will allow one cell to reach 3.60V and the battery will then calibrate to 100%.
If these errors still persist, or you want to continue charging at 14.2V [28.4V]* this is absolutely fine from a battery perspective, you will need to change a couple of BMS settings.
Please use the Roamer app, connect to the battery, and go to the settings page. Enter code 638203 (or your custom password if this has been changed). Make the following changes in order, as they must be done sequentially or it will not work.
Change 100% SOC calibration to 3.525V.
Change absorption voltage to 3.550V.
Change overvoltage protect to 3.700V.
Make sure you send the settings after each change by pressing the paper aeroplane icon and accepting the warning message.
This what we set as the default on SMART5 batteries.
The next time you charge to 14.2V [28.4V]*, the battery will calibrate to 100% correctly, as it will now synchronise at 14.2 (3.55V per cell instead of 3.60V).
*[] = 24v batteries.