Sunday, May 20, 2018

Tesla Battery Interface Wiring Diagrams Preliminary # 1


The purpose of the EVBimmer battery interface boards is to protect the Orion Management System and the sensor wires of the Tesla modules in the event of a short circuit or improper wiring.  An open circuit will be sensed by the Orion but a shorted lead will result in one or more blown fuses.  Orion indicates that the maximum voltage between any two terminals should not exceed 5 volts.

DSC06336 image of the preliminary wiring diagram that connects the Orion to Tesla module number 1. 

Cell 6A of the EVBimmer J1 Terminal Block on Tesla Battery Module #1 is connected to Cell 0 of the EVBimmer J1 Terminal Block connected to Tesla Battery Module # 2.

DSC06337 image of the preliminary wiring diagram showing how each Tesla module is daisy chained. 

NOTE:  A testing board is now being made that will mimic a pair of Tesla battery modules.  Using a series of resistors and the 12 volt supply ( required to operate the Orion ), it is possible to provide a chain of current limited low voltages that the Orion can sense and be monitored by the Orion software.  With jumpers it will also be possible to short out individual "cells" of the testing board and the Orion software will be able to respond to each change observed.

Orion BMS-48 Cell Kit Controller For Charging Six Tesla 5.3 kWh Battery Modules

An Orion BMS-48 Cell Kit controller was purchased ($1205) from EVolve Electric.  This kit included:

Main Controller
     Orion 48 (REV - E2)
     Serial # L4574D00 ;
36 Cell Tap Harness;
12 Cell Tap harness;
I/O Harness;
400 Amp Current sensor with (4) Pre-Wired Thermistors;
CAN adapter;
and a Utility Disk CD which contains the Orion BMS Utility
(also found here: );
Software Manual (also found here:  );
and Wiring Manual (also found here: ).

Since the Tesla batteries each have 2 thermistors and the six Tesla modules require a total of 12 sensors, an Orion Thermistor Expansion module was purchased ($207).  This module interfaces with an additional 80 thermistors.

To facilitate wiring the Thermistors to the Orion BMS an 6' Orion Thermistor Wiring Harness was purchased ($52) which has 20 pre-populated thermistor taps.

DSC05617 oblique view of Orion BMS enclosure.

DSC05618 bottom view of BMS enclosure

DSC05614 side view of Orion BMS enclosure (2 connectors + Ethernet?).  The Thermistor / Current Sensor socket on the far left connects to the white 16 pin plug labeled 371 and shown on the left side of picture DSC06316.  The larger white socket on the right is labeled the Main I / O Connector and it mates to cable CWHMIO2-W1546D19 shown in picture DSC06322 below.

DSC05613 side view of Orion BMS enclosure.  The far left socket is used for Cell Groups 1-3 and the middle socket is used for Cell Groups 4-6.  The far right hand socket is not used.

DSC05600 of the Orion BMS Thermistor Expansion Module that permits xxx different Thermistors to be monitored.

DSC05601 of the Orion Thermistor Expansion module (three connector)

Cable labeled WHTHEXPO2-W156640 (picture DSC06315 shown below) connects to the far right socket.

DSC05602 of the Orion Thermistor Expansion module (two connector)

DSC05609 top view of 400 amp current sensor.  As shown above, the power cable opening is 21.57 mm ID left to right, and 22.62 mm ID top to bottom.

DSC05608 of the current sensor showing the internal pins labeled D, C, B , and A.  This current sensor mates to the purple cable socket (part number CWHCURTH-W1559453) shown  below in picture  DSC06316.

The current sensor has the following markings:


Wiring harnesses that were included in the Orion BMS-48 Controller.

DSC05619 of the multiple wiring harnesses provided. 

The part numbers as printed on the exterior of the plastic bags were sometimes different than the part numbers located internally so both numbers are listed.

(starting at 12:00 - top center ):

CWH126-W1472408, with internal part number CWH126 KSM1915



This cable has 12 orange wires labelled 1 to 12 and 1 black wire labeled 1.  Plastic plug is labelled 369.

WHTHEXPO2-W156640, with internal part number of  CWHTHEXP02 KSM5216.



7 wires, with bottom row (as shown):
blue, black, purple, yellow and black.
top row with red, followed by 3 empty plug locations, and finally a red wire.  The first black wire is paired with the first red wire in the lower row.  The plastic plug is labelled 420.  This cable connects to the Orion BMS Thermistor Expansion Module in the far right socket shown in picture DSC05601.

CWHTP-W1574C00, this cable had an internal part number of  CWHTP KSM0817



A pair of wires, orange and brown.  Black cable covering.  8 wire plug using only 2 wires, orange and brown.  The plastic plug is labeled 384.

CWHMIO2-W1546D19 (bottom right of picture DSC05619) had an internal part number of CWHMI02 KSM4716.  The cable package also included 3 x 120 ohm resistors (DSC06334).



Appeared to be 18 wires, but the 2 black wires ( 1 short and 1 long) were actually 3 wires each, both sets covered in black sleeves.  The plastic plug is also labeled 371 and it connects to the right side socket shown in picture DSC05614 above.

DSC06334 of what appears to be 120 ohm resistors.

CWH366-W155550F with an internal part number of CWH366 KSM5116.



A black wire followed by 12 orange wires (labeled 1 to 12), then a black wire followed 12 red wires (labeled 13 to 24) , then a black wire followed by 12 yellow wires (labeled 25 to 36), and finally a black wire.  The black wires are labeled 1, 13, and 25.  The plastic plug is labeled 420.

CWHCURTH-W1559453,  this part had an internal part number of  CWHCURTH-D  KSM5016.


This cable has a white plug, a purple plug, and 4 pairs of black wires.  On the side of the purple plug (which has an external black housing and 4 wires connected to it) is indicated:  DELPHI  11  PBT-GF20.  This purple plug attaches to the current sensor shown in picture DSC05608 and 5609 above.  When the purple plug is viewed as in picture DSC06316 above, the far right is pin A and the far left is pin D.  

The white plug has 12 wires (4 go to the purple plug) and the white plug is labeled 371.

THERM2002-W1573D0B, which appears to have 20 thermocouples with 2 wires each.

CWHTHEX202-W1531B?  (center of picture), this part had an internal part number of HTHEX202  KSM4116. 




top row: black followed by 5 white, then black followed by 5 white.
lower row, identical to upper row.  The plug is labeled 371

DSC05620 of the CANDAPTER CAN bus interface with software

Monday, February 5, 2018

Tesla 5.3 kWh Battery Module Monitoring Board - Part 2

Previously (this blog 12/8/2016) the Tesla Battery Module Monitoring Boards were described and later an interface board (this blog 5/15/2017) that allows Tesla batteries to be connected to an Orion battery management system.

Jaroslav Alexa in the Slovak Republic (  ) made contact and he is working on a 1993 Opel Calibra .  He plans to maintain the 2.0i gas engine in the front but add an AC75 with Curtis controller that is powered with 4 Tesla batteries in the rear.  To interface the batteries he ordered 4 of the EVBimmer battery interface boards.

Picture JA214814 showing that the top of Jaroslav' board which appears to be equivalent to the boards previously examined (this blog 12/8/2016).

Jaroslav's Tesla battery board has the following markings:

PCBA, BMB, WIRE-CLP  (perhaps Printed Circuit Board Assembly, Battery Management Board)
1014183-00-0  Rev 0
2113C50004242  (perhaps 21st week of 2013)

Our Tesla battery boards have the following markings:

PCBA (1020796)
1021749-00-B Rev 03
0313KD0001147  (perhaps 3rd week of 2013)

Although the front face of the Tesla battery board appears to be identical to the boards that we have worked with, and it appears that both boards were manufactured at about the same time, the circuit board back side is different in that the sensor wires are directly soldered to the PC board without using any sockets.  (Pictures JA205319 and JA212739).

Picture JA205319 showing the back side of Jaroslav's board while it was being removed from the battery module.

Picture JA212739 showing what appears to be the same J1 inter battery connector (lower left with 2 green dots) but the other jumpers are all soldered directly to the PC board.
Picture JA215550 side view of  J4 (right) J3 (right top) and J5 (left center).   All connections were soldered to place.
If the white plastic connectors on the EVBimmer interface board are removed it is then  possible to directly solder the sensor wires to the board.

Picture JA212242 showing the connections after Jaroslav finished soldering the wires to the back side of the EVBimmer board.  He was able to make the new connections without removing the sockets on the front side of the board.  The wire leads from the Tesla module are not very long and a white wire was used to extend the length of the Tesla Orange wire.

Alternatively the sensor wires can be attached to the corresponding plastic connectors that would then permit direct connection to the EVBimmer board.

The surface mount connectors (male) used on the EVBimmer interface board are parts numbered S15B-PASK-2 (LF)(SN) and S04B-PASK-2 (LF)(SN).  Both can be ordered directly from JST in Japan.   As of this writing the S04B can also be obtained from  .

The corresponding mating connectors (female) that would then attach to the EVBimmer board's connector include the housings (parts numbered PAP-15V-S and PAP-04V-S) and the pins (part number SPHD-002T-P0.5 ).  All of these parts are available from  .  To attach the pins to the sensor wires requires a micro crimper and an Engineer PA-09 Micro Connector Crimper can be used.  The crimper is available for $38 from and can be found here: 

Tuesday, August 15, 2017

Tesla 5.3 kWh Battery Modules Bus Bar - Copper Prototypes

This posting is a continuation of the 6/18/17 blog posting which described a steel prototype bus bar to vertically connect multiple 5.3 kWh Tesla battery modules.

Calculations of Bus Bar dimensions.

The battery pack will initially be used with a NetGain Warp 11 motor and then later, using NetGain's new HyPer9 AC Motor.  The first motor (DC) is high performance but not easily cooled, while the AC motor can be cooled, driven with continuous operation, and it permits regenerative braking which the DC motor can not.

The specifications for both motors are as follows:

NetGain Warp 11 DC

Maximum input voltage: recommended at 170 V by some advocate 190 V

Minimum recommended input voltage:  48 V
Ideal input voltage: 144 V
200 amps for continuous operation
250 amps for 1 hour
500 amps for 5 minutes

NetGain HyPer9 AC Motor

Minimum input controller voltage: 65 V
Maximum input controller voltage: 130 V
Maximum output controller: 760 amps
Nominal input controller voltage: 100 V (120 V fully charged battery pack)
Typical fully charged battery pack voltage: 95-125 V

Normal driving amperage: 40-380 A, estimated average 200 A
Ideal amperage for continuous operation: <250 A
Normal acceleration up a steep hill: 400 A
Pedal to the floor amps: 750
Motor can provide 38 kW continuous

The battery pack under construction in this blog will be sized for 400 amps continuous current. 

Using information from the following location, 

suggests that copper measuring 1/8" x 1.00" will be good for 250-299 amps with 30' C rise under continuous use, or 350-399 amps with 50' C rise under continuous use.  Note that flat copper sheets will allow for better heat dissipation when compared to round wire.

Copper sheet 110 alloy, 0.032" x 12" x 24" was then purchased (McMaster Carr cat 8963K56, $43.96.  It is also available in bulk from Alro Steel, 0.032" x 36" x 108", at $223).
Laminated Copper Bus Bar Construction

It was felt that it would be more difficult to bend 0.125" thick copper sheets, so alternatively four 0.032" copper sheets were cut according to the drawing shown in picture DSC05985.  To allow for thickness of the plates and the dimensional losses expected due to bending, the terminal surfaces on each piece was slightly lengthened 0.125" .

DSC05985 of the bus bar template drawing. 

DSC05986 Multiple copies were made of the template and then they were laid out and taped to the sheet of 0.032" copper plate. 

DSC05990 Water jet cutting (a DXF or equivalent file would be required) may be preferable in the future, but for now the pieces were cut out by hand with a band saw and hack saw.

The original steel template along with a bus bar sheet were placed in a vice (DSC05994) and the copper sheets bent to desired form with a mallet..

DSC05994 showing the plastic hammer that was used to bend the copper pieces.  Initially one sheet was bent, trial fitted, and then placed back into the vice with a second copper sheet.  The second sheet was hammered down and the process repeated until all four sheets were tightly formed as is shown in picture DSC05993.

DSC05993 of the copper sheets after bending.  Initially the vertical dimension was marked on the inner face of the bottom copper sheet, and then the sheet was bent over the template corner.  Additional layers were then separately aligned with the bottom horizontal and left vertical edge of the first sheet, and then bent over the bottom sheet(s).  All of the horizontal tab lengths were intentionally made longer then required and then trimmed to final length in a single pass with a band saw.

When the four laminates were assembled together the mounting holes were drilled to accommodate the Tesla M8 bolts.

Vice grips were used to hold the left sheets together while the right side sheets were bent.

The most perplexing problem faced was how to bend two separate 90 degree bends while maintaining the required exact vertical and horizontal placement of the copper sheets.  It was elected to build a steel fixture that could be placed in a vice to hold all of the copper sheets together and allow both bends to be made before removing the copper sheets from the vice.  The fixture's dimensions were based upon the assumption that a single copper sheet was to be bent, and the upper layers would then be bent over the bottom sheet.

Construction of the Steel Bending Fixture

Two pieces of 836 steel measuring 1" x 5" x 12" and 0.625" x 5" x 12" were purchased from Alro Steel (Outlet store, 847-640-1111, $22.22 and $13.60 respectively). The thicker plate will function as the anvil and the thinner plate will serve to hold the copper in place while the bends are formed.

DSC06069 of the 836 steel plates that were used to fabricate a fixture that was then used to bend the copper sheets.

DSC06070 cutting the 1" plate.  The cut was more rapid and quieter after lubricating the blade with 10W30 motor oil.  The paper tape was placed and marked with pencil to make the endpoint more obvious.

When stacking the battery modules in the support frame, the plane of the terminals are separated by a 3.375" vertical distance.  A band saw was initially used to cut the fixture, and it was noted that the band saw blade curved slightly under load, so the step was initially cut less than 3.375".  The plate was then placed in a Bridgeport mill and the factory top edge was reduced about 0.010", and without removing the fixture from the mill, the side step was then finally cut to guarantee both parallel surfaces and the final vertical dimension of 3.375" .

DSC06073 showing the trial fitting of the previously welded steel bus bar prototype (6/18/2017 blog entry) when placed on the fixture. It was noted that apparently due to slight distortions during welding, neither of the faces of the steel template were completely flat on the "anvil" surfaces.  

DSC06075 close up view of the lower bus bar face during the prototype trial fitting.  Note the small gap between the "anvil" and the right edge of the bus bar that was caused due to thermal distortion during the welding process.  updated 5/6/18

DSC06087 showing the rounded corner of the lower bus bar face of the "anvil" that allows for the curvature of the 1/8" copper bus bar during bending.

Solid Copper Bus Bar Construction

It was difficult to cut the interior edges of the copper bus bars shown in picture DSC05986 (above) using a band saw.  Consequently, the 0.125" copper plate was initially marked using a Sharpie and a paper template.  The first cuts were then made with a Miller Spectrum 625 Xtreme plasma cutter (240 VAC, 35 amp setting), and although the copper cut rapidly, it was necessary to slow the linear movement to allow the molten copper to be blown free and not weld the parts back together on the back side.  A band saw was then used to refine the cuts followed by filing to smooth the edges.  To achieve final parallel and perpendicular outlines, the piece was mounted in the Bridgeport and all parallel lines machined (DSC06080).

DSC06080 picture of the 0.125" copper bus bar being trimmed with the Bridgeport.  The mill made it possible to make all horizontal lines parallel to each other and all of the vertical lines perpendicular to the horizontal edges.   The rounded corners were trimmed with a band saw and then sanded with a metal file.

DSC06091 showing the final solid copper bus bar prior to placing in the vice with the faceplate.  In the future, MIG welding of a 0.0625" horizontal shelf or ledge directly below the lower edge of the copper bus bar along with a 0.0625" vertical edge to the immediate left of the vertical portion of the bus bar, would provide for reproduceable placement of multiple bus bar blanks.

DSC06092 of the copper bus bar pressed between the anvil and the front plate,

DSC06096 after bending the 0.125" copper bus bar flush to the horizontal surface.  It was very easy to bend the copper and both faces of the copper bus bar fit perfectly on the battery module terminals without any changes being required.  At this point, with the ease of the use of this bending fixture, there is no longer any reason to pursue the original laminated copper bus bar design.

Bus Bar Installation

To guard against accidental contact and possible electrical shorts to adjacent areas, the bus bar was wrapped with Kapton tape (McMaster Carr 7648A734) and then covered with a fiberglass sheath (picture DSC05999 and DSC06105, McMaster part number  7324T19 ).

A temporary nylon tie off was placed at each end to help minimize the unravelling of the fiberglass cloth.

DSC06000 Kapton Polyimide tape (McMaster Carr 7648A734, 3/4" wide, 15 feet long, 0.0025" thick, 5 yds $8.88)).

DSC6101 of the copper bus bar after application of the Kapton electrical insulating tape.

DSC05999 of Fiberglass High temperature sleeve (McMaster 7324T19, $5.36, 3/4" ID, 60" long.)

DSC06105 of the installed final copper solid bus bar with the fiberglass sleeve.  The horizontal distance between the midlines of the M8 bolts in the  + and - terminals on the battery module is 9.0"

updated 9/2/17, 12/9/17