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Minor4326 LTO Conversion

23241 Views 480 Replies 18 Participants Last post by  Rainsux
I wanted to document the layout and external (Peter) boards I use, my questions and the answers I received as well as my build techniques. This current thread starts out with old posts from several threads.

Before I started my project I studied jime build threads JimE LTO Conversion JimE LTO Conversion and LTO Layout #2 LTO Layout #2 Since then I’ve used ideas from Natalya LTO Conversion thread

Here’s jime’s diagram of the plate I copied in which to mount the three LTO packs. I modified it at the red line and used the red dimensions so it would fit easier.

Drawing Technical drawing Parallel Line Diagram

I used .25 x1 1/2" (Metric equivalent) fine thread for hold down bolts on the LTO packs.. That gives a 12mm head and fits through the spacers and holes in the tabs.

Since I have not made the final install yet I have made two choices for spacers: 1 1/8 x1/2 diameter aluminum spacers with 1/4" holes. Since alignment of all this is difficult, I used slightly larger holes, like 5/16 holes. I also have 1” hollow, square aluminum tubing with holes drilled in the appropriate locations. I used a piece of wood as a transfer template for hole locations.
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I don't know where to connect the four LTO pack connections. I've taken a picture and labeled what I think are the connection points. I don't want to get this wrong so please tell me what goes where.

Jim Epting Oct 11, 2019 To Me
Your #1 is the total pack negative. Your #4 is the total pack positive. The #2 & #3 are the middle of the pack.

You will want to test the cover clearance with a long straight edge of some sort anyway. Check the BCM/MCM fitment with them installed in position, in the square hole and attached as ‘permanent’.

Another pic from thread to document
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jime Cable Layout This pix shows how the cables are to be routed for Layout #2. There are several options for which battery to split this group so the 6 subpacks are equally split with respect to the junction board switch - which I view as desirable. I have chosen to split the left rear pack looking forward from the hatch. This arrangement seems to result in relatively equal length cables. I could find no other arrangement which did so.
I have attached temporary tags on the important cables so that their function can be identified. The low-side cables, with respect to the switch, are black. The high-side cables are red.

Since my own configuration has the BCM/MCM underneath the plate, they do not show in this pix.

I believe that this is the easiest configuration to build, since most folks are probably going to want to use IMAC&C. (edited by correcting one battery cover polarity)
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minor4326 #717 @retepsnikrep - can you tell me if a 125A fuse has a large enough safety factor when a 30% current hack is utilized

retepsnikrep #718 I've just bought 125A l50S fuses as they were very cheap on flea bay

minor4326 #719 this is a diagram I composed from threads for MCM and BCM connectors and the wires that are connected to the BCM Fooler, Current Hack and BMS Mini Interceptor.


minor4326 #720 Just picked up 7 feet of BMW battery cable for $4.80. Since the 12V battery cable for all the BMWs I've seen is in the back of the car I figured the gauge was at least 4AWG. Incredible deal. NOTE: it’s actually 2AWG, better deal!
minor4326 The BCM fooler board – according to the schematic, White to MCM (battery negative, J14 on your board) and Red to MCM (battery positive J13 on your board) are connected to MCM connector E, same color wires, pins 4 and 8; the other connector points on the Fooler board are connected to the BCM (connector C). The MCM Red and White points are same electrical point as J1 (white) and J12 (Red) on your board. These points appear to be redundant; do these + and – connections need to be connected? Can just the 12 wires be connected?

retepsnikrep #723 Re Fooler connections; have a look at the bottom of the board.
If you don't use J13 for the battery + input then the safety led won't work. It shows when the board is energized with HV and is a useful safety feature. J14 is a duplicate of J1, but gives a standard layout with the HV battery input connected to the left side of the board, and the BCM output to the right.
minor4326 #724 I'm looking for the battery pack temperature sensors in the wiring diagram. I believe there are four. I assume these temp sensors are connected to the MCM? Maybe the BCM? Can someone please tell me to which connector and what is the wire designation of the said connector for these sensors. Thanks

eq1 #725 They connect to the BCM, connector B. I'm looking at a page from the electrical troubleshooting pdf. The connections are called "TBATT":
connector space

You can look for yourself in the pdf shop manual, the folder "electric troubleshooting manual," click the 'index' pdf, the 'ima system' entry, and then down in the left corner there's a link to the BCM. There's probably other docs that show similar things.

jime #726 Like eq1 said, they are in colored plastic sheaths with two wires each in the sheath.. They have different lengths so you can plug the plug in, but wait until you see how the batteries are going to be positioned before you decide which sensor goes to which subpack. Use the hole already in the cover, since you can't tape them into place with the cover installed.

I "think" you need to use a little bit of heat shrink material to insulate the tips from the cell tops.

You will have to load the version of the Interceptor S/W which is configured for temp sensors.

retepsnikrep #727 The BCM Interceptor has nothing to do with the physical Temp Sensors. (It doesn't connect to them). It does/can however fake the temperature reading sent from the BCM to the MCM to a minimum of 25/30C for maximum IMA power if reqd.

jime #728 OK, but I don't understand how that works with regard to reading temperature on the OBDII C&C. The temperature probes hook to the BCM, so seems that the data to the OBDII would be unmolested. I guess the question is, "Will the OBDII C&C display the battery temperature or the faked temperature?"

Just checked car. Displayed battery temperature is 27C (86F). Temperature, early in day after a cool night, should be roughly 60-64F. Apparently it is displaying the faked temperature and the temperature data is therefore unresponsive.

retepsnikrep #729 The BCM reads the battery temps sensors. It sends the high/low temperature data to the MCM.
The BCM interceptor intercepts that message and if activated sends a fake temperature if desired. The actual temp is sent through if it is higher than the selected faked temperature.

The OBDIIC&C displays whatever the BCM interceptor is sending through to the MCM.
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minor4326 #739 It's incredible your LTO cells kept such close uniformity. You mentioned that you balanced the pack two years ago.... what process / procedure did you use?

insightbuyer #740 Yes it is quite amazing these cells stayed in basically perfect balance. This is because they were made in Japan I believe with very good quality control. Plus they are in a very good case and protected.

I actually never balanced them, they came shipped to me all within .003 volts. I actually cycled a few cells when I was testing them.
minor4326 #742 as I get my pieces together to convert to LTO I decided I wanted additional structural integrity for the BCM/MCM... made a nice difference. I added a strip of 0.125 aluminum (the width of a wooden paint-stir) to the underside so it lays directly across the 'outside module. I used rather medium-sized self-taping screws.
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minor4326 #744 Today I installed the plate with the BCM/MCM modules connected. I was pleasantly surprised that despite my inattention to the height obstacle, the cover fits without interfering with the sandwiched modules. Today I did a dry run to be sure my cables connecting the LTO packs were the correct length and the electronic board and connectors 'fit'. I have to adjust two cables' lengths due to the BCM/MCM modules interference in-space. I can say one thing though, the harness is a huge PITA to make plugs fit, and the original + and - cables from the DC-DC now are too long. When I do perform the installation I will use a heat gun to warm-up the harness to make it more pliable.

minor4326 #775 I'm mounting these vertically like jime first showed. My layout will be like his as well, two/one layout.
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jime #745 on the harness, it helped a great deal to take off the wire loom and factory tape and reshape the harness to your special needs.

minor4326 #773 This what I did. I re-taped the BCM/MCM wiring harness to conform to a better shape for installation then I put additional strain relief in place.
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minor4326 #757 I’m tracking down what was said by retepsnikrep with regard to allowing a 72-cell LTO pack voltage to be seen in its entirety. I believe the information is included in posts #34 and #41 (Another LTO Conversion Thread).

The easiest and simplest way to ensure everything stays in line voltage-wise and in the correct proportions or percentages when you have a higher voltage pack than standard is to use:
1) The simple resistor 10 x 10k voltage divider matrix (for the) BCM Fooler.
2) An inline series resistor in the Vpin line wire (MCM Connector B, ORG wire pin # 16) and
3) the addition of an extra resistor in the Fooler positive feed of a value that matches the one in the Vpin line.

Example: a 72-cell LTO pack battery is 180V resting and we want 160V, so that's a 20 volt reduction, or about 11%... use an 11k resistor in the Fooler + feed and in the vpin line. 10k is near enough in my example.

Two Question: 1) My Fooler uses 20k matrix resisters to reduce the parasitic current loses. It was stated: “A 1k resistor added into the orange vpin wire between MCM & MDM equals a faked 1% voltage reduction, so 10k= 10% etc. Can I infer that I insert two 20k resistors (10% = 20k) when a Fooler matrix uses 20k resistors? 2) is the Fooler positive feed the Red-to-MCM connection?

retepsnikrep #759 If you are using 20k Fooler resistors, then 1x20k in the Fooler positive feed = 10% reduction. 1x10k in the vpin wire = 10% reduction.

minor4326 #768 I soldered the eight 1k 0.25w 0.1% resistors onto the MCM board today... it's a bit tricky due to the close proximity of connection points... not for the faint of heart. I used Purple's pics as a model. She did an outstanding job! EDIT: I’m going to re-do this with 1/8 W, 1% resistors that are 3mm in length.
Picture references Purple’s thread Adria's [purple] LTO conversion and related mods
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This is how I attached my cables to the electrical board. Reference Natalya’s LTO Conversion Post #3
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Insulated cable covers I used can be found on ebay, for $7.08 for a 3-pack Blue Sea 4008 CableCap Stud Insulator 3-Pack Insulate stud type connectors
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minor4326 #776 @Peter – when installing the resistor between the Fooler positive feed J13 (same as MCM connector E pin 8) (so the system sees a reduction of my 180V LTO voltage) can I cut the small plug and wires from the loom and connect directly to the Fooler board J13 and J14. I would connect both the red (with resistor) and white wires directly to the Fooler board. I would insert the 1x10k in the vpin wire (MCM connector B pin 16) at a later time.
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retepsnikrep #777 I think so.
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minor4326 #778 Just installed the resistor onto the BCM board as part of the (wireless) current hack mod. I saw an old Current Hack Resistor Value Matrix from Peter that suggests the best value resistor to use in the MCM is a 233 ohm (rare), not a 240. The closest 1% I could find was 237 ohms, so I used it. I assume the matrix is still accurate.

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retepsnikrep #779 237R is fine for the BCM. The matrix is ok but the % increases are wrong IIRC they are underestimated, +30 = actually +40%
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minor4326 #780 Just finished re-soldering the Current Hack resistors inside the MCM. This time I used resistors that are ~3mm long. That's the only way to go!
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minor4326 #782 I attached the + and gd wires for the Interceptor. I removed the wire pins from the plug and soldered them together. I pulled the pins out so I could heat-shrink them properly.
I also connected two of the wires for the Interceptor. Two more left in the same fashion. On the butt connections I used Terminal SST-S11. Very slick!
EDIT: I forgot to say that the white bar 'inside' the connectors need to be lifted/pushed-up to enable the release mechanism in the pin. This needs to be done for installation too. Doesn't need to be lifted much, maybe 1mm
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minor4326 #783 What is the best method to connect the four Insight battery temperature monitors to LTO packs. I believe they go on the top in a small previously identified area, but what means are they attached?

jime #784 The way I did it, after analyzing the wire lengths and finding the locations you want:
1. Use the "edge" fold of a piece of stick heat shrink to form a small envelope to hold the sensor tip. Scotch tape the sides.
2. Use a bit of heat conductive grease to make good thermal contact.
3. Thread the sensor wires through the cover holes and then tape the sensors to the small mid block bare spot with Kapstan tape. (use a tiny square of thin foam to apply pressure to the sensor tip.)

minor4326 #785 Did you ever consider wrapping the sensor in foil to increase the heat transfer?

jime #786 No, IF electrical insulation is an issue, then foil would allow a short. I don't actually KNOW that electrical insulation is an issue, but the sensor is insulated from HV in the original. Maybe Peter can speak to the insulation issue.

retepsnikrep #787 I wouldn't use exposed foil inside the packs.
Just heat shrink over the sensor end and then wedge it, glue, stick it etc into position.
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I'm going to copy-paste the post with Peter's answers, as best as I understood them, in BOLD.

Four things I learned with I didn’t notice before are:

- Change Pic to -2680 for CAN capability;

- Replace J1 5-pin with another connector that has as many openings as one wants; The new plug will still be connected as it is now and soldered onto the PCB by the 5 original soldered pins but for additional openings this will be a ‘connection point’ for your increased wire OBD2 cable going to under the dash;

- it may be easier to get an OBD2 receptacle that goes under the dash from another car since this ‘new’ connector will have additional wires already. Pull pins from the salvaged connector and attach the new CAN wires from the final LTO sensor board. Reinsert the two pins into the existing, original OBD2 connector.

- 120 ohm across last two of daisy chain because high speed - to reduce reflected signal.

Great video! Interesting how you put the 4-pin connector on-top of the LCD connector and connected the Yellow and Orange wires from the Daughterboard. Since the LCD is disconnected are you simply using the disconnected pins on the PCB (formally to the LCD) as a meeting place. NO, see further. Since these are the Daughterboard Tx and Rx ports, what do these wires connect to? ? The LCD is disconnected but the PIC processor is not. These yellow and Orange wires will now connect only to the PIC since the LCD connections have been clipped.

You connect the Blue and Green wires from the Daughterboard to the LTO canbus. That would be for individual LTO cell information, right? Is there a means to connect all the LTO packs to the CANH or CANH lines, or all of the LTO CANBUSs together? For all the LTO information to be connected the LTO balance board plugs need to be daisy-chained. After all LTOs are connected in series, daisy-chained, there will be two remaining unconnected wires. These two wires will go to the BUSS interface daughterboard that is now connected to the OBD2C&C. (See Peter’s video, Post 142). 3RD Gen Civic Lithium Battery Project

This wiring (colors) need to remain consistent. An example of this is to use White and Yellow(CANL) be IN connections and Brown(CANH) and Blue(CANL) be the OUT going to the next pack. Keep this consistent. Would those connections/wires be: White (CANH), Yellow(CANL), Brown(CANH) and Blue(CANL)? YES What about the redundancy of H and L connections? These are the IN and Out for daisy-chain connections. I guess that’s what’s needed to automatically read all the cell voltages? YES

If you have LTO Sensor Board the 8 pin connector with 6 wires are:

Red (V+) DC Supply (I have used 7-12vdc)
Black (V-)
White (CANH) CAN Bus (IN)
Yellow(CANL) CAN Bus (IN)
Brown(CANH) used for Daisy-chain (Out)
Blue(CANL) used for Daisy-chain (Out)

I've got questions about the Canbus:

You indicate CANBUS wires CANH and CANL need to be brought up from the back and inserted into the OBD2 connector under the dash, right? Where would these two wires initiate from? They initiate at the LTO packs themselves and need to be brought-up to the OBD connector under the dash. As stated above if one wants to read all the LTO packs the end of the daisy-chain is these two wires.
I’m confused about CANH and CANL. On post 1 above you do the following list of pin-outs: #6 CanLCar Tx connected to OBDIIC&C connector OBDII plug Pin 14 and #7 HLine from OBDIIC&C connector J1 Pin 3. Aren’t these points the same? Ignore the above since CAN H is different than HLine
You mention hooking-up and using a relay with extra wires. What would that relay do? You mention battery charger? Did not discuss.
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@ Peter. Is your OBDIIC&C CANBUS UPDATED SCHEMATIC 19/01/2018 appropriate and up-to-date for this project?
retepsnikrep #28 That schematric is basically the original; OBDIIC&C schematic + the CAN daughter board and a jumper to switch the G1 HLINE to CANL when plugged into an HCH2 Civic.

In my latest LTO videos we aren't bothering with the jumper, as the unit is dedicated to the LTO setup and doesn't need to be configurable for an HCH2 setup.

For LTO just do what I have shown in the various new videos..


minor4326 #790 I replaced the tiny resistors on the MCM board with Peter's Current Hack board because I wanted the 0.1% tolerance the 1k resistors offered.
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minor4326 #791 I went junk-yarding Saturday with the intent to add parts for the LTO-pack voltage sensing and CANBUS mod in the future. I retrieved wire from my favorite source car, BMW X series, and an OBD2 connector from a Honda. I'll add the wire to the removed-pins and reinstall them into my OBD2 plug under the dash.
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