Troubleshooting - Charging not working

If charging is not happening when expected it is usually because one or more of your set values is preventing it from charging. 

A simple way to fix is by re-running the wizard as this will enter the default values for your battery chemistry and therefore potentially fix if you have deviated and not sure.  It's like a reboot of your settings.

If controlling charging using an inverter connected to the WatchMon via CANbus 

The important values are in Control Logic -  Remote

Check things such as if communication is occurring back and forth

Check that scaling is appropriate.  For example do the Actual and Target look right or are they a factor of 10 out?  

Note: not all inverters transmit back the value (Actual)  If it doesn't report this it will have blanks in Actual and you would need to check the inverter to check.  

The inverter reporting back is nice to have but not essential.

Check if Actual is above Target.  It won't charge in this scenario, so the BMS is doing what it is meant to do.

If controlling charging using a contactor or similar using Charging logic.

The important values are in Control Logic - Charging and Hardware - Expansion Settings

Check your wiring - If the output is set to Manual On does charging work?  

If it doesn't work check wiring and if confident of wiring try alternate output making sure you are using fusing to prevent damaging the output. 

It is very easy to damage these outputs if you aren't careful and this damage is not covered under warranty

Check Charging state - is it in the state you are expecting?  

If in ON state and not working check your wiring again or check if using correct Expansion Option.  Charging ON is the most common one we use.

If in OFF state and you think it should be in ON state check your settings in Charging Logic

For example one scenario that would stop charging is shown below where Cell Hi Resume has been lowered.  The system works that initially it will charge till it reaches the Cell Hi Cutout then be in the off state till the Voltage drops below the Cell Hi Resume.  This example shows Actual is above the Cell Hi Resume therefore it is still off.

Other issues may be ignoring the requirements to allow balancing to effectively occur by allowing limited. 

  • Low power must be enabled on charging tab.
  • Low power current should suit the bypass capability of CellMon.
  • Charger voltage target needs to be sufficient for all cells to reach bypass threshold.

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