Tesla 5.3 kWh Battery Module Monitoring Board - Part 1

The recent availability of salvaged Tesla battery packs has led to efforts to repurpose them for solar applications (see reference at end below) and it might be possible to use them in this BMW 325i EV conversion project as well.   The primary concerns with using salvaged Lithium ion batteries include the condition of the batteries when received, and the additional requirement of safe handling when later charging and discharging the batteries after installation.  For safety, either the purchase or the development of a battery monitoring system capable of controlling 6 or more of the Tesla modules, each containing essentially 6 batteries (36 total) is a must.  For purpose of better understanding and possible reverse engineering of the Tesla battery control board, a monitoring board was purchased from K-Ash on Ebay.  (Picture DSC05118)



Picture DSC05118 of the component side of the Tesla battery control board.  There is one of these boards located on each battery module.

The board as received was copyright 2012, and it is labeled PCAB (1020796).  It has a white sticker labeled 1021749-00-REV 03 and 0314C60002094.  The board is designed to monitor the 6 cell groups contained in each module. 

The black 16 pin chip (U4) on the upper left of the board is an SI8642 and it is an isolator chip to separate high voltage from ground.  http://www.silabs.com/Support%20Documents/TechnicalDocs/Si864x.pdf

The black 64 pin chip (U1) in the lower center (largest chip) of the board is a Texas Instruments TI BQ76PL536A battery monitoring chip.  http://www.ti.com/lit/ds/symlink/bq76pl536a-q1.pdf

The C8051F536 microprocessor (U100) that controls the board is immediately to the left (and slightly higher) than the 64 pin battery monitor chip (U1).   http://www.silabs.com/Support%20Documents/TechnicalDocs/c8051f52x-f53x.pdf 

                     

 Picture DSC05126 showing the  three connectors used on the reversed side of the Tesla battery control board.

The long 15 pin white connector (J3) is a JST S15B-PASK-2 (the mate to this connector is JST PAP-15V-S and it uses SPHD-001T-P0.5 crimp pins).  It is labeled as Cell 6, 4, 2, 0, 1, 3, 5, with every other pin left unconnected for further voltage isolation.   The cable that attaches to this connector is terminated at six different locations on the battery pack.  

The large black 10 pin connector (J1) is a Molex Mini-Fit Jr Series 5569 and it is available from DigiKey ( http://www.digikey.com/product-detail/en/molex-llc/0015978102/0015978102-ND/3157084 ). 

The corresponding mate to J1 can be purchased here:  http://www.digikey.com/product-detail/en/molex-connector-corporation/15-97-5101/WM4772-ND/1624637

The small white connector (J6) is a JST S4B-PASK-2 and the mate is JST PAP-4V-S.  The pins are labeled TS1+, TS2+, TS2-, TS1-.  These are the thermistor leads (Temperature Sensor).

The Tesla PC board is fastened to the module housing with four black attachment pins.

Picture DSC05236 showing one of the mounting points with the inserted attachment pins.  Using a pair of needle nose pliers the small center pin can be pulled out (DSC05237).

Picture DSC05237, once the pins are fully removed, the remaining black piece pulls smoothly away from the battery module's plastic frame.  




Picture DSC05127 showing the dimensions of the Tesla battery control board.  These dimensions can be used to fabricate a proto board that can be directly attached to the existing 5.3 kWh Tesla battery module. 
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UPDATED 12-31-2016
Error: the 102.5 noted as the horizontal distance between the left and right mounting points in the picture above is actually 92.5 mm.

Picture DSC05357 showing that the BMS side of the board actually has a total of six mounting points that may be used when fabricating a replacement printed circuit board.  The left four were described above, but the right two were discovered upon further examination.  The top row of three mounting points are all 49 mm above the bottom row of three mounting points.  The distance between the far left pair and the center holes is 92.5 mm, and the distance between the center pair and the far right pair is 79 mm.
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Examples of Tesla Modules being used in a Solar Project

An example of a solar project is http/wk057  where an off grid battery system was constructed that used 36 batteries (191.25 kWh) from 2.25 salvaged 85 kWh Tesla cars. ( https://teslamotorsclub.com/tmc/threads/plan-off-grid-solar-with-a-model-s-battery-pack-at-the-heart.34531/ ).  The project also includes an attempt to produce a custom BMS controller as a plug in replacement for the Tesla battery control board.  Some pictures of that project can be found here:   
(  https://teslamotorsclub.com/tmc/threads/in-development-inexpensive-custom-bms-for-tesla-battery-modules.51095/  )


Par 2 of this blog was posted on 2/5/2018?