Several weeks ago I was getting strange behavior from my PakTrakr battery monitor. To be more specific, the display unit would often indicate false alarms and erratic voltage measurements. The thing that surprised me the most was that the display characters would often be garbled and this would happen while my car was powered off sitting still in a parking lot for several hours. During this behavior, I had to fallback to my reliable analog gauges for voltage and current readings. Boy am I glad the analog gauges were installed.
I initially contacted Ken Hall (the maker) who sold me the BMS and explained the situation. He told me that these types of symptoms are commonly seen in high current EV conversions due to EMI and suggested that I try adding Ferrite Choke Cores to the twisted pair data cable between the display unit and remote unit. I tried this without any success and returned my possibly defective display to Ken for further investigation. Unfortunately, Ken tested the display unit and was not able to reproduce the problem(s) I was having. At this point I began researching the problem on the Internet and came across a few exact cases. I read many forum postings to the point where my mind was overloaded with information.
PakTrakr Goes Nuts Motor EMF
PakTrakr Data Noise
EMIControl in Electronic Governance
I read about people testing their PakTrakr units using oscilloscopes and determining that noise was entering the display unit because it used the high voltage from the pack as it's power source. Suggestions were made that the PakTrakr monitoring system should use a separate power source or have in line filters to eliminate any noise. In addition, it seems that many PakTrakr customers have provided valuable feedback for product improvements but some of these improvements have not yet been implemented. I started getting discouraged to the point where I am now considering returning my entire BMS kit if one more last attempt does not resolve the issues.
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9 years ago