Blog - Battery Monitoring

FAQ: Improving the communication of BMS123 in an electrically noisy environment.

By now the BMS123 has been supplied to over a hundred installations in various projects. Majority of the customers have been fully smooth when installing the BMS123. Following the feedback of some of the customers, we have prepared some tips how to improve the stability of the BMS123 system.

In systems with high electromagnetic interference rate it might happen that BMS will lose communication with balancing modules. A typical examples of an noisy instillation is an  electric vehicle with a DC brushed motor. 

Check some of the tips to improve the function of the BMS123:

Tip 1: Use the twisted shielded UTP cable for connection of the IN and OUT Modules with Main controller

Tip 2: For even higher resistance to electrical noise, we recommend to use special CAN Bus shielded twisted pair cable. (See photo)

Tip 3:  If your battery pack is separated to several small packs, you should use the same twisted pair cable(s) between all of the IN and OUT modules.

Tip 4: The shielded cable is effective only if the shielding is grounded properly at both ends.

Tip 5:  In case of EV application please make sure your motor, controller, charger and DC/DC inverter are grounded to vehicle chassis. 

Tip 6: Use shielded cables for all high power traction wiring. The cables should be as close as possible, avoiding any loops or split wiring.

Tip 7: Use the ferrite coils on all wires to reduce the noise emissions. Check the details here.

Tip 8:  The cable supplied with the current sensor is not shielded. In high DC voltage systems this cable may receive some interference. You may replace current module cable with a shielded twisted UTP cable, or other type of a twisted shielded two-pair cable for better results.

Tip 9: If all problems persist, you may have the BMS Main controller unit located at a place where EMC (electro-magnetic compatibility) noise is highly concentrated. You can try to move the controller to some other location or place the unit into a protective metallic shielding case.

Tip 10: It is always good to check recommendations how to prevent EMC interference with the manufacturer of components, which are the source of EMC noise (motors, inverters, controllers, DC contactors, high voltage power line, etc.)

Note: loosing communication of the BMS by an external interference is not a valid reason for a warranty complaint. Replacing the product would most probably not improve the situation!

Be sure to check with us if you need additional support for your BMS123 installation.