DIY Electric Car Forums banner

1986 CRX EV conversion (Nissan Leaf Donor) - Now Running and Misc upgrades

57271 Views 636 Replies 23 Participants Last post by  remy_martian
I'm new and am planning to convert my 1986 Honda CRX into an EV. I have a 2015 Fiat 500e for parts but from what I know so far, the Fiat is sensitive and difficult to use for parts. I believe it uses the Bosch 180/120 based on my Google fu. I've sourced the wiring diagram for the vehicle and confirmed it is indeed a 3 phase AC motor, one for each phase, 2 wires to sense temperature, and another 6 for the resolve (excitor, sin, cos). The biggest challenge is that Fiat uses canbus and the controller, inverter, battery, and more likely will not operate without all the parts. The car almost disabled itself when I changed the radio to android auto makes a good example. I am studying how canbus works in order to see if I can either ignore errors or maybe even hack the system to work.

As back up if I have to build from scratch, I have a separate thread pending approval where I'm asking about the compatibility of the Bosch SMG 180/120 with the Scott drive 250 AC controller.

Also I'm reading I might need an inverter? And what else? I'm still digging through the site trying to figure out what are all the parts needed to run an EV with an AC motor, which seems to be more complex and less popular than running DC. So guides or hints are welcome as I learn the anatomy of an EV.
==========
Edit (2021-12-06):
Current project is now to convert the 1986 Honda CRX using a 2013 Nissan Leaf as a donor car in combination with the Resolve-EV Controller.
==========
Edit (2021-12-23):
Project has begun; Battery Dropped; still need a machine shop to make parts.
==========
Edit (2022-07-14):
Car has been running since June 2022. Car has been inspected by the California Referee Station and certified as an EV. DMV has issued registration though they're still trying to figure out internally how to actually label my car as an EV.

My latest work on this build has been to upgrade the battery from 24kwh to 40kwh. Batteries are installed but I still am working out the BMS issues as a bruteforce upgrade doesn't accurately recognize the battery capacity differences.

The to-do list is on-going and always evolving so although the car is running, I'm likely to be doing some new upgrade or change all the time.
==========
Edit (2022-10-23):
Started building a battery box which is the "final battery" box. Still in the planning state but measure many times and cut once.
==========
Edit (2022-12-27):
Battery Box is built and now revising the bus bars and BMS connections to the latest design.
==========
Edit 2023-01-10
Got it running on 2022-12-30. And got it back on the ground and took it on a road test 2022-12-31

Been cleaning up and doing misc upgrades since.
601 - 620 of 637 Posts

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #601 ·
Misc research about SOC and reached out to Jim who is developer for Leaf Spy and he stated that GIDS come from the VCM which I don't have so all I have is the SOC from the Leaf BMS itself.

As for the Leaf BMS, I found here that the BMS supposedly uses the current to measure SOC.
Source: Nissan LEAF Teardown: Lithium-ion battery pack structure - MarkLines Automotive Industry Portal.
To quote:
The current sensor is directly mounted on the service plug, which has two built-in elements with different characteristics. The magnetic field generating the current is detected at the core section (black cube in the photo) which generates voltage. The SOC (State Of Charge) of the battery is calculated by measuring the battery current and integrating it in time.
(*Note) The battery SOC is individually measured for all cells.
From other quotes, it does seem like the Leaf BMS is already using Columb Counting

Source: Real SOC (State of Charge) - Information - My Nissan Leaf Forum.
It was recently asked how I derive SOC for LEAFSCAN. This number is simply obtained from the Battery ECU, and is displayed as-is. The various Leaf systems use this as a basis for making operational decisions and displaying information. The SOC is created by coulomb counting, which is basically defined as counting the electrons passing in/out of the battery. Due to the fact that it's not actually possible to do this very accurately in a mass-produced EV, the battery ECU periodically makes adjustments to keep the SOC as accurate as possible. One of the main ways this is done is by checking open-circuit voltage of the pack and applying some math to correct this number for things that will affect it, and using a lookup table of known states. This all working together makes for a pretty accurate SOC calculation. The Leaf's engineering team make use of a hall-effect based current monitor to perform the coulomb counting, and these have a number of issues that make them less accurate than ideal, but they are cheap and good enough.
Another thing to consider is that if I've fully charged the Leaf battery, then the BMS columb counting method works as it now has a starting point for its measure of SOC.

My conclusion is thus that the SOC being returned is "relatively" accurate and possibly unaffected by the SOH.

That all said and done, I still plan to try and measure the kwh/mile when I can next drive it (atmospheric river rain storms for the last few weeks) and see if it lines up with the other theoretical numbers.

If possible, maybe try and calculate the SOH as well.

Will play with axles tomorrow.
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #602 ·
Got busy and didn't get to the axles. Maybe tomorrow. @Electric Land Cruiser was in San Jose so we met up and chatted about EVs and cars. Hopefully it won't be pouring rain next time hes in town so we can actually take the CRX out for a spin.

Did some misc exploration of CANBUS and found I needed to have a receiver acknowledge the CAN Messages I was sending. Pretty noob moment but I learned I need at least two nodes in a CAN network with one acknowledging the transmission sent from my USB interface. Otherwise the tx sent is considered failed. Lesson learned.

I've been reading all I can into CANBUS and picked up an Adruino and canbus shield so I guess I'll be building that second CAN node.

Continuity tested all the wires in the CANBUS adapter and found they didn't match up with the Kvaser Leaf Light just as I guessed. 11 dollar cable vs 70 dollar cable. So I chopped it.

Gadget Audio equipment Comfort Electrical wiring Vehicle


All I needed to work was ground, CAN High and CAN Low

The rest were unnecessary for the adapter:
Hand Twig Wood Electrical wiring Terrestrial plant


Cheap 11 dollar cable works now I suppose. Did continuity check and resistance check and it was good.
Electrical wiring Gas Cable Electrical supply Auto part


Its cold and raining outside so this setup is rather comfortable. But I still need to build that second node.

Computer Personal computer Laptop Electrical wiring Audio equipment
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #605 ·
Tried to get some axle work done.

Some time last year I made a spare set of axles. The passenger side axle with the intermediate shaft didn't fit. It was an inch too long. So I chopped it today to redo it.

Even after cutting it... its still too long
Automotive tire Motor vehicle Bicycle part Tire Rim


Did some grinding to correct the size and also remove the pipe I welded on it.

Its finally the same size now:
Automotive tire Coil spring Coil Auto part Rim


Welded and side by side comparison.
Gas Auto part Engineering Nickel Metal


Test fitted and it fits this time lol.

Took a break to feed the kids. Came back after their bedtime to start disassembling the axles

Motor vehicle Automotive tire Wood Engineering Gas


Leaf passenger side.
Wood Gas Cameras & optics Engineering Machine


Got the snap ring off and it just slides off. Nice!

Wood Household hardware Gas Machine Auto part


Couldn't figure out how to take out the wheel (CRX) side...
Automotive tire Motor vehicle Automotive wheel system Bumper Gas


Automotive tire Bicycle part Gas Motor vehicle Engineering


Driver side axle. Leaf side:
Bumper Automotive tire Wood Gas Auto part


Also stuck here with the CRX wheel side...
Automotive tire Water Gas Plumbing fixture Font


Posted looking for help and so far someone said the snap ring is inside? I'm guessing its on the shaft...

Which means I need a bigger hammer and need to use more force. Will try sometime this week.

Going to try what this video suggests...

If all goes well, then I'll either take these to a machine shop locally as a template to cut the Leaf axles to size and add CRX splines. or I will send them off to Colorado for them to machine me custom shafts. Or both.
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #606 ·
So I hurt my wrist and then shortly after got sick so I ended up taking a break.

Was healthy enough to drive to work today. When leaving the car looked cool so I took a picture lol.

Automotive parking light Automotive side marker light Tire Wheel Car


Drove various speeds from 0-80 MPH with stop and go and free way speeds. Calculated 140 Miles total range to work and 142 miles range coming home. I'd say I drove "aggressively".

Another thing to note is I can't figure out how to track wH in Leaf Spy. I have a reason to believe the app gets the data from the ECU which I don't have.

Looking at this chart, we can see that Battery Wh is "na". There is a current "Bat Power" which also appears to be the W being consumed. I'm not sure if I can leverage it or log it well enough to calculate the wH being consumed though.

Rectangle Font Line Parallel Technology


Which brings me to question, how do other builds track the wH per mile? The mile part is easy to track with trip meter but wH requires likely a current sensor, voltage sensor, and a logger. It feels like Leaf Spy should be able to get me this data but maybe I have to create a custom screen somehow...
 

· Registered
Joined
·
5,397 Posts
Cool - the ones on eBay are rather spendy.

There's also an iPhone app by RevHeadz that peels off the data from an OBD-II dongle to produce various sounds, including V8, motorcycle, Ferarri etc.

It got annoying after 10 minutes, and I haven't used it since the first tryout. It's nice to actually hear Premium Sound in the car 😎
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #609 ·
Cool - the ones on eBay are rather spendy.

There's also an iPhone app by RevHeadz that peels off the data from an OBD-II dongle to produce various sounds, including V8, motorcycle, Ferarri etc.

It got annoying after 10 minutes, and I haven't used it since the first tryout. It's nice to actually hear Premium Sound in the car 😎
The Resolve EV is a bit tricky since it didn't have all of the regular OBD2 messages we'd normally find in other cars. I don't think the RevHeadz would even work in this case because we don't have all the CANBUS messages in a regular car.

Like the Throttle position, is a secondary torque message that comes from the Resolve EV itself since the pedal is wired directly into the Resolve EV Controller.

The motor and inverter also are reporting RPM/Torque which they managed to tap into but its goes nuts when we go into reverse because the values go from 00 to FF and start decrementing. When in Drive it starts at 00 and increments. So what happens is the active sound thinks you're at full throttle when in reverse because its expecting 00->FF and not FF->00. Its probably an EV problem in particular because EVs don't need a reverse gear. The just spin backwards and the Leaf motor/inverter is setup to report it that way.

So the support guys at Thor are going to see if they can handle/support a decrementing value with "limits". TBD.

On the plus side I learned a lot about what CANBUS signals are reporting what.

MSG ID 539 comes from the Resolve EV controller.
D0 is for 01-Drive/02-Neutral/03-Reverse
D2 is usually 03 but when on Drive, 03 means coast while 01, 0B are two different levels of regen braking

1DA is the Inverter/Motor
1D4 is the "torque request" and likely its the Resolve EV Controller sending those messages

I'm going to dig around more for the battery SOC when I have a chance and I plan to wire it all to report into the Insight cluster when I can.

I found someone had dug into the cluster a bit so I'm going to have to try it out myself too
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #610 ·
Finally got out to garage to do work on the axles again. Used a hammer. Got one cv joint off.

Automotive tire Bumper Hood Tool Gas


The other one... Was impossible.

I eventually shattered the cage that holds the bearings which allowed me to remove it but when I opened it up, I still couldn't get the shaft out. I ended up having to cut the gear to get the shaft out. The clip or ring is inside and covered so even with the cage broken, I can't reach it. It's either hammer it out or press it out. Or cut it off.

Automotive tire Style Asphalt Font Wall


So since that's broken I ordered a few more cheap CRX axles to see if I can get their hubs/joints and if they're similar shape and size.

Hand tool Metalworking hand tool Tool Gas Auto part



Automotive tire Bumper Bicycle part Bicycle tire Bicycle fork
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #611 ·
Misc Learning about Leaf batteries and bad cells.

I joined the Leaf subreddit mainly to learn about misc Leaf battery/motor things and today I learned something interesting I thought I'd share.

To quote:
A sudden drop in voltage when under high load is a sign of a bad cell. It usually recovers once the load is removed.
Source:
https://www.reddit.com/r/leaf/comments/10ov5kg/_/j6hdn8y
So I thought I'd do some research to verify since this seemed like what happened with my last pack.

And it looks like there are other sources like this one which had the same "error message" I had with my old battery pack with a bad cell.


The key I'm taking away is to watch for large deltas in the cells when under load. Voltages will drop but if one drops significantly more or to dangerous levels, then it's a bad cell. And from my experience, it's a good idea to replace that cell before it shorts the whole battery pack.

Makes me wonder what is a good "load" to test a leaf module to check if it's a bad cell or a good cell. Coming up with a "diy accessible" approach would make it much easier to source and verify batteries. Food for thought.
 

· Registered
Joined
·
1,970 Posts
Acceleration draw of 60 to 120 Amps would reveal a weak cell. Laefspy would show it instantly and the car would go to Turtle mode when it is bad enough.

Measure the Open Circuit Voltage and then the voltage under the known load, and measure the load current. From this you can calculatus the "internal resistance" as another indicator for comparison to look for a weak cell.
 

· Registered
Joined
·
8,530 Posts
To quote:
A sudden drop in voltage when under high load is a sign of a bad cell. It usually recovers once the load is removed.
Source:
https://www.reddit.com/r/leaf/comments/10ov5kg/_/j6hdn8y
Measure the Open Circuit Voltage and then the voltage under the known load, and measure the load current. From this you can calculatus the "internal resistance" as another indicator for comparison to look for a weak cell.
It makes sense to me that the voltage drop only while under load (and proportional to load) is the result of high internal resistance in that cell, and it seems plausible that high internal resistance is an indication of cell failure.
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #615 · (Edited)
Insight Cluster Research for later:

LiBCM has RS485 with the requisite 120 Ohm resistor. The MCM also connects to METSCI, but the MCM only "listens" for two different packet types... we could have several hundred/thousand other message types that the MCM would wholly ignore. Also, since we know the MCM broadcasts a packet every 100 ms, we know that T+3 ms to T+97 ms is wide open. Long story short, Pegasus and LiBCM can talk to each other over METSCI.





A METSCI man-in-the-middle. METSCI is the RS485 bus that tells the cluster which IMA info to display.
Looks like I'm going to learn how RS485 serial communication works lol


Edit:
After finally reading through 22 pages of that crazy "controlling the instrument cluster" thread, 5+ years of work they've been doing on the cluster, I've come to conclude the METSCI1 and METSCI2, Serial communications, operate on RS485 and take messages from the MCM and BCM. I saw that there was challenges in keeping the cluster "on" after those serial messages were sent. I've through it all and found a single MCM-METSCI Packet Encoding.pdf file in the thread. I'm not sure if I missed any other packet or encoding samples? There was also a lot of discussion about the timing.

So I think my path forward is to learn how to build an Arduino device that sends the RS485 messages to control the SOC and other Charge gauges. I suppose it'd be pretty funny if I hooked up the "brake regen" to the Assist gauge.

I've already figured out the CANBUS signals coming from my EV which determines SOC, Charge, Regen, Gears, etc. So the Adruino device will be a MITM.

My biggest challenge is that I don't have an actual Insight, just the cluster, so any sample data dump of serial messages being sent on METSCI1/2 to the cluster would be source from that community or the PDF file I attached. I don't think I can figure it out otherwise. And then of course figuring out how to keep it from "turning off after 5 seconds" since that appears to be a weird issue I didn't see a solution to.

Packet Encoding file attached.

Also wiring diagram:
Rectangle Slope Font Schematic Parallel
 

Attachments

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #617 ·
Got two new axles from Rockauto. Also got a tool that can supposedly separate the axles shaft from the outer CV Hub.

Automotive tire Bumper Rim Bicycle part Motor vehicle


And here is the tool...
Automotive tire Bicycle tire Motor vehicle Tire Crankset


How it is supposed to work... is as you tighten the axle nut, it will push the shaft away from the CV Joint hub.
Motor vehicle Automotive tire Gas Engineering Vehicle


Short to say is it didn't work. And eventually the bolt just broke
Tool Hand tool Font Cutting tool Everyday carry


Got new bolts. Tried again. Tried both axles. Neither would separate. Went back to hammering... neither would come apart.

So now I'm thinking about what to do next... Should I keep trying to separate the axles? Can I force it out some other way? Maybe Hydraulic Press?

A few ideas... I have two axles. I could cut the hub for one in order to get the cage out. Maybe find someone with a hydraulic press than can press out the shaft?

There has to be a way..... or maybe I find some professional somewhere I can ship these off to be fabricated.
 

· Registered
2015 Leaf, 1964 Oliver 1800 Tractor
Joined
·
25 Posts
I watched the video you posted about rebuilding. As you know, there is a snap-ring inside that should just require some force to pop it out. Looking at the tool you bought, It looks to me like it is for assembly not dis-assembly. The black part is clamping on the shaft, and the big nut is applying force to the end of the shaft, pushing them together, not apart. Or maybe I'm not seeing something.

Seems like you need something like a slide-hammer that could attach to the end of that tool. Let the black bars loose enough to slide down the shaft. Perhaps get a piece of pipe a bit larger than the shaft, cut a 1" piece of it off, split it in half and wrap it around the shaft so the tool butts up against it and it pushes just on the inner race. Then attach the slide-hammer shaft to that puller and give it a good whack.

Perhaps the reason just using a hammer is not working is that it is applying force unevenly and causing it to not release the snap-ring on all sides.

Are you wanting to replace the hub-end end with a Honda spline-end? Do you still need to change the length as well?
 

· Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
439 Posts
Discussion Starter · #620 ·
I watched the video you posted about rebuilding. As you know, there is a snap-ring inside that should just require some force to pop it out. Looking at the tool you bought, It looks to me like it is for assembly not dis-assembly. The black part is clamping on the shaft, and the big nut is applying force to the end of the shaft, pushing them together, not apart. Or maybe I'm not seeing something.

Seems like you need something like a slide-hammer that could attach to the end of that tool. Let the black bars loose enough to slide down the shaft. Perhaps get a piece of pipe a bit larger than the shaft, cut a 1" piece of it off, split it in half and wrap it around the shaft so the tool butts up against it and it pushes just on the inner race. Then attach the slide-hammer shaft to that puller and give it a good whack.

Perhaps the reason just using a hammer is not working is that it is applying force unevenly and causing it to not release the snap-ring on all sides.

Are you wanting to replace the hub-end end with a Honda spline-end? Do you still need to change the length as well?
I made two sets of custom axles and I needed a replacement CRX outer CV joint. One was to verify the outer joint I broke is compatible and two is to have a replacement once it came time for me reassemble the axles.

It took me awhile to figure out how the tool would work before buying it. The black side clamps the shaft. The axle nut side would "pull" the CV joint away from the shaft as you tighten the nut.

I scoured the internet for hours searching for a solution and I might have found it on eBay lol.

I was hoping to find a CV outer joint rebuild kit since it used to be more popular to rebuild that just replace the entire CV half shaft.

And I found it on eBay finally

Outboard CV Joint for HONDA Civic 84-91 CRX 84-91 HO-1-04-015
Pictures from the ebay listing.

Automotive tire Fluid Automotive lighting Alloy wheel Hubcap


Audio equipment Gas Wood Nickel Metal


If it matches then I'm good to go.
 
601 - 620 of 637 Posts
Top