A quick demo of the Cell Log 8 Breakout Module

This is just an update to share a quick demo of the electricporsche.ca Cell Log 8 Breakout Module.


This is a very simple but highly effective breakout board to allow safe and easy connection and use of the Cell Log 8 (CL8), it has provisions for 32 series cells using 4 CL8’s.  The alarm’s of each CL8 are isolated from each other and powered by the first 4 cells in a group.  It is important to note that there must be at least 4 cells connected to a CL8 for the alarm’s to function properly.

There are three methods of interfacing with the breakout module to make use of the CL8 alarm signal.  The first and simplest is an NC (normally closed) loop, when there is an alarm condition on any breakout module the NC loop is opened indicating a fault.  This system requires the use of additional hardware to make use of the NC loop.  A simple and existing solution would be the Head End board sold by Dimitri at Clean Power Auto LLC.

The 2nd and most inexpensive method is to use the RJ45 connector on board with a Cat5/6 cable and 4 resistors/LEDs.  The 8 wires in the Cat5/6 cable are connected to the Com and NO terminals of the 4 alarm relays.  By connecting pins 1,3,5,7 to the respective negative terminals of 4 LED’s and connecting pins 2,4,6,8 to the cars ground, then connecting 12v through appropriate current limiting resistors to the positive side of each LED you have a simple display that will indicate an alarm condition along with which CL8 triggered the alarm.  Use a suitable length Cat5/6 cable to mount your LED’s in a suitable location so it will be noticed while driving.

The 3rd and most customizable method of interfacing with the alarms is to use the NC/Com/NO terminals on the bottom of the Breakout Module and create your own interface.  This could be anything you imagine, for example it could be connected to digital input pins on an Arduino microcontroller connected to an Android tablet that displays an on screen warning of the alarm condition as well as the battery group that triggered the alarm.

All of the alarm related connections are completely isolated from battery system it’s monitoring, making it safe to run the alarm wiring into the vehicle cabin to a convenient location.

I will add the CL8 Breakout Module to the store shortly, I won’t be selling the Cell Log 8’s though.  If you are buying Cell Log 8’s from Hobbyking.com I would highly recommend you also purchase the Turnigy 3mm flat screwdriver similar to what I used in the video.  This screw driver fits the terminal block screws on the Breakout Module perfectly, it’s good quality and very inexpensive.


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