Tesla P85 Powered 818C

[kimchikimkim]

INTRO: Ok, time for another EV Project. After many years of my family talking about wanting to buy a Tesla, I finally convinced them to let me build one for them instead. I don't have enough time to do another ground-up build so I went the kit car route. Budget is the primary constraint on all projects but with significantly more budget on this project compared to others, I hope to cut a few corners as possible. I bought a 2002 WRX off of Facebook Marketplace a few months back for $1000 and completely stripped the car selling close to $5000 in parts from the car while keeping parts that I needed (A alot of that money was due to me not going with ICE). I bought the drive unit from a Tesla off of eBay making sure to avoid flooded and rear-ended crashes as they are usually severely damaged in such accidents and thus unusable. I will control the tesla motor with an Advantics VCU (due to Tesla OTA Updates and CAN IDs constantly changing, it is close to impossible to get one spinning with stock DSP logic by CAN Captures thus the board requires a reflash from a company that specializes in reverse engineering Tesla Drive units, Advantics.) I will use a Digital Dash from AEM and reprogram the DBC Files to read data from the Cars CAN bus. To make full power I will use 2 chevy spark EV 2016 batteries. These are LG Chem/ GM Gen 2 battery packs. They can make crazy power and also are safe to fast charge (Up to 50kw a piece). This means that I can safely charge 2 full packs using CHAdeMO a very easy standard to implement compared to CCS GreenPhy/PLC Nonsense. Charge (0-100%) times should be around 45mins with a 50kw DC fast charging.


UPDATES: I will update the google photos album and my Youtube but I will also try to do little writeps on my progress here in case people want to do a similar build.

CURRENT CHALLENGE: As of now, I am working on modifying the frame to fit the Tesla Drive Unit. The motor makes a ridiculous amount of power for its size so I'm overdesigning the mounting points everywhere I can.

Basic Specs:

FFR 818C + 2002 WRX Donor
Tesla LDU Sport 2014 (1200a IGBT power stages making around 636hp)
Advantics VCU
AEM CD5 Digital Dash
2x LG Chem - Chevy Spark EV 2016 Battery pack 36kwh around 150 miles of range
CHAdeMO + J1772 Charge support
2x Lear 3.3kw OBCs Gen 2
Delphi 2.2kw Bidirectional DC/DC Converter
Orion BMS V1

Projected weight: 2100 lbs


Google Photos Album:https://photos.app.goo.gl/akbdh1tJnDSf5RMD9

Youtube Channel: https://www.youtube.com/channel/UCY0p_b3BAqAJ0CHL2w4W53Q

Any questions/comments/suggestions are welcome as always!

[JohnK]

Sounds like a very cool project. Any concern with going the CHadeMO route? Nissan's abandonment of it and adoption of CCS can't be a good sign for the future of CHadeMO, I would think.

[Alan_C]

Subscribed, please put together a build thread so we can see the progress. The final result should be a lot of fun!

[kimchikimkim]

Sounds like a very cool project. Any concern with going the CHadeMO route? Nissan's abandonment of it and adoption of CCS can't be a good sign for the future of CHadeMO, I would think.

CHAdeMO is dying but at only $150 for a vehicle-side connector (through Alibaba) I couldn't pass up the opportunity. Also in the SF bay area (where I am from) the DC fast chargers usually have both plugs CCS and CHAdeMO. This infrastructure is likely not to change for a while. I know CCS is 100% more common and the number of them is growing but the cost of implementation in a DIY EV as of now is high and requires significant knowledge. Since it is combined with J1772, it should be an easy upgrade down the road especially after the folks over at Openinverter finish reversing engineering the BMW i3 LIM Box making it work reliably on stations worldwide.

[kimchikimkim]

Subscribed, please put together a build thread so we can see the progress. The final result should be a lot of fun!

I will try my best! As for now I will continue to upload pictures on the goolge photos album I setup above. Thanks for your interest.

[J R Jones]

kim3, I am intrigued by your concept, and reviewed a couple videos, so questions:
You are running 636 hp 2WD, not awd?
FFR recommended the motor in front of the axle, but that would require running the drive in reverse, and the lube system will not allow that?
So, you will have a rear weight bias and lots of power. You know about snap oversteer I assume. Have you predicted weight and distribution?

I intend to repower my 818, electric is looking good.
Are there other motors with drive behind the motor? A cursory look suggests hybrid rear axle motors are kinda puny.
With your research do you know of a motor closer to 300hp?
thx, jim

[Frank818]

Where are you located?
There is one 818C with Tesla motor(s) in Ontario Canada for quite a few years, now. Maybe you know him.

[kimchikimkim]

Where are you located?
There is one 818C with Tesla motor(s) in Ontario Canada for quite a few years, now. Maybe you know him.

The EV Controls 818C is what you're referring to I think. Awesome project! I do not know the guy however. He uses his vehicle as a test bed for his CAN Spoofing Tesla Drive unit controller.


I am located in California.

[kimchikimkim]

kim3, I am intrigued by your concept, and reviewed a couple videos, so questions:
You are running 636 hp 2WD, not awd?
FFR recommended the motor in front of the axle, but that would require running the drive in reverse, and the lube system will not allow that?
So, you will have a rear weight bias and lots of power. You know about snap oversteer I assume. Have you predicted weight and distribution?

I intend to repower my 818, electric is looking good.
Are there other motors with drive behind the motor? A cursory look suggests hybrid rear axle motors are kinda puny.
With your research do you know of a motor closer to 300hp?
thx, jim

The weight distribution with be 60/40 ~ish and yes I am worried about snap oversteering. AWD is possible by using a P85D/P100D front drive unit (AKA SDU). The controller I am using can actually control both at the same time with traction control implementation! Budget is holding me back on that end, otherwise I would make it AWD. Keep in mind just because the motor can make 636 HP doesn't mean I will use it all. The Advantics VCU that I am using to control the drive unit has all sort of programable limits that you can set over CAN. Also you can run the drive unit in reverse with a replacement aftermarket oil pump from ZeroEV in the UK. That being said I was able to fit the motor by doing some frame mods and fabricating a subframe.

If you want to make around 300hp a small drive unit will do the job nicely paired with an appropriately rated traction pack. You cant beat the price to performance of OEM Motor/Inverter/Gearbox combos.

[J R Jones]

Kim3, I have not been here long enough to have seen precedents of motor power and your predicted weight distribution.
I did drive a replica GT40 with a VW flat four behind the axle and the front end did not inspire confidence. Despite auxiliary weight, understeer and brake lock-up were issues.
It was not an impressive build in all regards, but lessons were learned.
Thanks for the update. I did find the 85 series Tesla has the power I mentioned. Steep learning curve for me.

The Tesla drive gears are likely not straight cut, helical is likely. I have no experience running helicals backwards. I would be concerned about gear durability despite revised lubrication.
jim

[kimchikimkim]

Kim3, I have not been here long enough to have seen precedents of motor power and your predicted weight distribution.
I did drive a replica GT40 with a VW flat four behind the axle and the front end did not inspire confidence. Despite auxiliary weight, understeer and brake lock-up were issues.
It was not an impressive build in all regards, but lessons were learned.
Thanks for the update. I did find the 85 series Tesla has the power I mentioned. Steep learning curve for me.

The Tesla drive gears are likely not straight cut, helical is likely. I have no experience running helicals backwards. I would be concerned about gear durability despite revised lubrication.
jim

Again, the motor can always be detuned. One of the reasons I went with a tesla drive unit is the packaging, efficiency and reliability. The inverter alone is built so far ahead of its time. Tesla gears are helical too (on all of their drive units I'm pretty sure). Keep in mind we are talking 12inch rear bias over the rear axle something that is far less than an entire engine and trans in both weight and distance.

[kimchikimkim]

Update: The drive unit is tacked into place (with very minimal chassis mods!) I will finish the welds up at a future date on TIG. I received and installed the Advantics VCU as well as reflashed DSP/Logic board. Next up is getting custom drive shafts made for the motor. Here is some pictures of the build so far.

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[hineas]

This is an awesome project. I'm definitely going to be following

[Frank818]

So what axles are you going to use? 12in long? But what specs? Diameter, splines, any mods to Subie hubs/spindles, etc....

You may be right about that Ontarian 818Tesla, but what about yours, will you be using it mostly on the never-rainy-streets or beautiful CA?

I hope you will keep us frequently updated, very curious to see all the design mods you will go with to fit this unit!
I did subscribe to your channel.

[kimchikimkim]

So what axles are you going to use? 12in long? But what specs? Diameter, splines, any mods to Subie hubs/spindles, etc....

You may be right about that Ontarian 818Tesla, but what about yours, will you be using it mostly on the never-rainy-streets or beautiful CA?

I hope you will keep us frequently updated, very curious to see all the design mods you will go with to fit this unit!
I did subscribe to your channel.

Thanks for your interest and subscribing to my YouTube.

I will be using custom axles (from driveshaft shop) and I might need to add STI Rear spindles from a 2006 as the spline is physically larger due to the power of the tesla drive unit. I am designing the car to be driveable in any weather so fully waterproofing all the electronics and making some water tight battery boxes. Just as a heads up I might drop off the radar for a few months as I am going back to college and cannot work on the car during that time. Otherwise I will be updating as soon as I make meaningful progress.

[jmccabe]

Great project! I look forward to following your build.
I have had my my Electric FFR MK2 Roadster on the road since 2016. I had plans to eventually change over to a model S drivetrain, but found my chassis would need extensive modifications due to the width of the motor- inverter . I see people splitting and stacking the two now. This will work, so I think this might inspire me to move forward. When I do it will either be a ModelS or Model3 motor.
Bye for now, Jeff McCabe

[kimchikimkim]

Great project! I look forward to following your build.
I have had my my Electric FFR MK2 Roadster on the road since 2016. I had plans to eventually change over to a model S drivetrain, but found my chassis would need extensive modifications due to the width of the motor- inverter . I see people splitting and stacking the two now. This will work, so I think this might inspire me to move forward. When I do it will either be a ModelS or Model3 motor.
Bye for now, Jeff McCabe

Thanks for the interest and I would love to check out your electric MK2. Im pretty close to San Jose.

[J R Jones]

kim3, I have researched the Model 3 RWD motor application and it looks good to me, but....
I researched the battery and find dimensions / weight: (inches) 85L X 58W X 4.1H and 1060 - 1200 lbs.
Pretty big for my 818.
I have seen a ten second electric AWD 818 and he ran someone else's batteries (VOLT?) but to get the performance, how much smaller can they be?
jim

[kimchikimkim]

kim3, I have researched the Model 3 RWD motor application and it looks good to me, but....
I researched the battery and find dimensions / weight: (inches) 85L X 58W X 4.1H and 1060 - 1200 lbs.
Pretty big for my 818.
I have seen a ten second electric AWD 818 and he ran someone else's batteries (VOLT?) but to get the performance, how much smaller can they be?
jim

The 818C from EV Controls uses Gen 1 Chevy Volt packs. Those packs are known to have a high discharge rating and can make alot of power. The Tesla model 3 drive unit is a good choice for sure too. I would look into a Kia Soul EV Battery pack or something similar, The Soul uses Lipo based pouch cells which have a super high discharge compared to Tesla (using 21700 cells optomized for energy weight density, not power). Look around for any salvage EV battery packs there is a ton of info online.

[kimchikimkim]

UPDATE: Worked today on building up one of the battery boxes in the rear. I plan to use Riv-nuts to hold the brackets in place. Also I learned that STI rear and front Spindles are something that I should be considering as they are much stronger than the spindles on the WRX. Since I'm using the Tesla Drive unit I figured it might be a good idea to pick some up. Problem right now is that they are super expensive and I cant seem to find any new if anyone knows where I can pick some up please let me know. I need to get them ordered ASAP so I can get the custom drive shafts made.

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[J R Jones]

kim3, I too have a 2002 donor, so your comment on STI parts upgrade intrigued me. I could not see a difference in WRX/STI however the parts changed in later years (post 2006?) but those supposedly do not fit a 2002. I am unsure if it is a fitment issue or just different.
BTW the Kia Soul EV batteries are 639lb each, I have not found dimensions. Looks like they doubled output for 2020.
jim

[kimchikimkim]

kim3, I too have a 2002 donor, so your comment on STI parts upgrade intrigued me. I could not see a difference in WRX/STI however the parts changed in later years (post 2006?) but those supposedly do not fit a 2002. I am unsure if it is a fitment issue or just different.
BTW the Kia Soul EV batteries are 639lb each, I have not found dimensions. Looks like they doubled output for 2020.
jim

Depends on what parts you're talking about. STI 2004 spindles are 27 spline vs 25 WRX spline as far as I can tell. Otherwise there are slight casting differences from what I see in my research.

[J R Jones]

kim3, Ahh, I did not look at axles and hubs.
I am concerned about how to integrate the Subaru shafts with the Tesla output gear splines. It is optimistic to think the CVs will marry-up.
BTW as mentioned in an earlier thread on this site, the axle bearings in the rear uprights (spindle) are not robust. Later Subaru vehicles upgraded to a bolt-on bearing carrier, but I do not know if it can be incorporated into an 818, or if the bearings are more robust. The roller style bearing has lower thrust load capacity than ball bearings like Mitsubishi uses in the EVO.
jim

[kimchikimkim]

UPDATE:

Today I finished mounting the Tesla Motor and fully welding/painting the brackets I made to fix it to the frame. I was going to TIG but got lazy so MIG it was lol.

I'm leaving for college in a few days so this might be a good stopping point and time for me to clean up. I will most likely update in December.

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[Frank818]

You actually bolted the engine mounts to the frame? That's a great idea, makes it a lot easier in case of major maintenance or repair or anything, you can get it out of the way.

Unless those MIG welds besides the bolts are in fact welding the engine mount to the frame? Then what are the bolts for?

[kimchikimkim]

You actually bolted the engine mounts to the frame? That's a great idea, makes it a lot easier in case of major maintenance or repair or anything, you can get it out of the way.

Unless those MIG welds besides the bolts are in fact welding the engine mount to the frame? Then what are the bolts for?

It is slotted and welded to another plate like so:

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[Sgt.Gator]

Do you follow Dennis Palatov's EV work, particularly his D9? https://www.dpcars.net/d9/index.htm
The D8 is also available as a EV.
He has formed a sister company based on his fast swap battery modules.
Their D2EV attempt at Pike's Peak:

https://youtu.be/I3rAvDqywyw

The Palatov FB page: https://www.facebook.com/PalatovMotorsport

[kimchikimkim]

Do you follow Dennis Palatov's EV work, particularly his D9? https://www.dpcars.net/d9/index.htm
The D8 is also available as a EV.
He has formed a sister company based on his fast swap battery modules.
Their D2EV attempt at Pike's Peak:

https://youtu.be/I3rAvDqywyw

The Palatov FB page: https://www.facebook.com/PalatovMotorsport

I have not seen this before. Thank you for linking it, very interesting. I really like the pushrod-based suspension design.

[dokujaryu]

I'm looking at doing something similar as well, and I'm considering a Tesla drivetrain, but also others. What's the final drive ratio of the rotation of the electric motor and the wheel? It seemed like the Tesla unit has a 4.5 final drive ratio? So like with a 25" tall tire 8000 RPM is 132MPH? Does all that sound about right?

If you don't use a Tesla drive train, how do you gear down before you hit the axle? Use a traditional diff? What if you go dual motor? Diff in front and back for all wheel drive or like, drive back wheels with two motors somehow?

Is there a better place to ask these questions?

[dlud]

I'm looking at doing something similar as well, and I'm considering a Tesla drivetrain, but also others. What's the final drive ratio of the rotation of the electric motor and the wheel? It seemed like the Tesla unit has a 4.5 final drive ratio? So like with a 25" tall tire 8000 RPM is 132MPH? Does all that sound about right?

If you don't use a Tesla drive train, how do you gear down before you hit the axle? Use a traditional diff? What if you go dual motor? Diff in front and back for all wheel drive or like, drive back wheels with two motors somehow?

Is there a better place to ask these questions?

Regarding other places to look: http://www.diyelectriccar.com/. I am doing a scratch build Tesla now using a Tesla S Sport large drive unit. The final drive is 9.xx. The motor spins north of 16,000 rpm. Tesla uses large diameter wheels, 20 or 21". The differential is integral to the drive unit. If you wanted to mount it longitudinally for some reason and run it through a differential, Zero ev in the UK makes a replacement gear set that gets you down to the 4.xx range. And I recall seeing someone who has a u-joint adapter to run a normal drive shaft...don't remember who.

[kimchikimkim]

I'm looking at doing something similar as well, and I'm considering a Tesla drivetrain, but also others. What's the final drive ratio of the rotation of the electric motor and the wheel? It seemed like the Tesla unit has a 4.5 final drive ratio? So like with a 25" tall tire 8000 RPM is 132MPH? Does all that sound about right?

If you don't use a Tesla drive train, how do you gear down before you hit the axle? Use a traditional diff? What if you go dual motor? Diff in front and back for all wheel drive or like, drive back wheels with two motors somehow?

Is there a better place to ask these questions?

I would use the transfer case and not mount the motor longitudinally if possible. Might as well reuse as much of Tesla's engineering as possible.

[kimchikimkim]

UPDATE:

After some consideration I decided to transfer colleges in order to work on projects like this more often. Because of this, I expect some significant progress in the upcoming months!

Over thanksgiving break I was able to secure a deal on 4 corners of WRX STI 2004 as well as 2/4 pot breaks all around for 580. I decided to put a new wheel bearing in and clean them up while I was at it since I didn't trust the (only "60k miles") that the seller was advertising. Upon further inspection I wouldn't be surprised if these knuckles were used in an actual rally car since they were packed with dirt. These knuckles support the larger 27 spline rear hubs and are much better suited to take up the power of the Tesla LDU. I also decided to rebuild the calipers since the appearance was in very rough shape. I was super happy that I ended up rebuilding the brakes since there was a huge amount of crud built up on the front 4 pots from what I think to be caused by a bad seal. I ended up cleaning it all up with a wire wheel and some sand blasting which took forever but I want to have very solid brakes. A full rebuild kit for the brakes as well as wheel bearing/seals is waiting for me at home right now! I put some pictures of the rear calipers below. All paint for brakes has been VHT caliper paint and VHT epoxy paint for knuckles. I have also finalized the color for the car as well, I want to make it completely while all around with black accents (hence why I painted the calipers black). I'm really looking forward to finishing up this semester of school and getting back on it asap!


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[Ajzride]

Buy a powder coating kit from Eastwood and a used oven on craigslist for 25 and put them to use on those components while you have them apart, you won't regret it.

[roadrashrob]

AJziride is correct! Powder coating is easy and makes for a great end result. I bought an oven on Craig's list, then built a larger cabinet to fit all the larger 818 parts, but the end product is totally worth it! Then I was donated a standard sized oven I use for smaller parts, so now I have a dual oven setup. Just saves electricity when I can use the smaller oven.


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[kimchikimkim]

I would but I am already done painting them up with VHT! I also don't have room for an oven anywhere in the garage right now.

[J R Jones]

kim3, The VHT paint is intended for brake calipers and I assume the operating temperature range. That is appropriate.
The racing and track day cars I have run have burned Wilwood and Brembo caliper paint. That was obviously extreme.
Hard braking especially with battery weight may develop brake temperatures that will melt powder coat paint. I recommend high temp paint.
jim

[kimchikimkim]

Yeah exactly. That being said I don't think the brakes will be doing much as regen should take care of most of the braking 90% of the time. That's the main reason I went with VHT, it is rated for higher temps than a powered coat at the cost of a surface that isn't nearly as durable. If it starts to give me problems down the road I will fix them but for now, I will keep them as is.

[Ajzride]

I saw a youtube build on a Lotus that was converted with a Tesla powertrain and he rigged up the paddle shifter to be a regen brake controller, so that the harder he pulled the paddle the more regeneration braking was applied. I thought that was an awesome concept. Something worth looking into.

[J R Jones]

Kim3, I read about regen braking in terms of recovering energy but not pure brake performance, like distance to stop vs speed or G-force developed.
In 2WD I speculate brake coordination with the non-driven axle is challenging. Even cumulative effect of regen + friction brakes would be a challenge. Worst case being a panic stop or downhill into turn 5 at Elkhart Lake at 150MPH. I read that F1 has done it but at what cost?
Coordination with ABS?
jim

[kimchikimkim]

I saw a youtube build on a Lotus that was converted with a Tesla powertrain and he rigged up the paddle shifter to be a regen brake controller, so that the harder he pulled the paddle the more regeneration braking was applied. I thought that was an awesome concept. Something worth looking into.

That’s awesome but I don’t feel comfortable enough but to design my own controller to modulate regen power over CAN. I know it’s fairly simple but since it’s safety critical I plan on trying to isolate the powertrain CAN to only a few devices. Down the road I would want to add this but I already have enough battles to fight as if now. Thanks for the tip!

[kimchikimkim]

Kim3, I read about regen braking in terms of recovering energy but not pure brake performance, like distance to stop vs speed or G-force developed.
In 2WD I speculate brake coordination with the non-driven axle is challenging. Even cumulative effect of regen + friction brakes would be a challenge. Worst case being a panic stop or downhill into turn 5 at Elkhart Lake at 150MPH. I read that F1 has done it but at what cost?
Coordination with ABS?
jim

I do not know nearly enough to comment on this, especially on the driving characteristics of regen but I know that regen is not made to be used to stop extremely fast. I believe this comes down to the huge inductive surge caused by slowing down the rotor and limited space for dc link cap (again not sure but that’s what my intuition thinks). I would assume F1 has a pretty sweet inverter powering the motor and can handle a huge amount of bemf. The bottom line is that I will only be using regen to coast to a stop (as soon as my foot leaves the gas pedal it will be activated). If I want to slow down faster I tap the brakes and rest of the stopping power is all mechanical. As far as traction control goes I will have none (at least until I can afford going AWD).

[kimchikimkim]

Update:

Today I was able to finish pressing the hubs and bearings in the four corners. The bearings feel super smooth and so much tighter than the wrx knuckles with 200k+ miles on them. I cleaned up the garage making more space. I also designed a battery shelf that I will continue to fabricate throughout the week and weekend. I also purchased a ton of new bolts off of mcmastercarr to replace the wrx bolts since a majority were severely overtorqued and the zinc was wearing off one of the many previous owners. I wanted to replate them but my dad told me about hydrogen imbrittlement and it scared me enough to shell out money to just get new fasteners. Here are some pictures of the progress!



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[Sgt.Gator]

Saw this and thought of our EV 818 folks:

1,500 ft-lb Torque Electric Powered Shelby Cobra Tesla KILLER


https://youtu.be/wW7J2DkRaO0

[BrettR]

Hi Kimchikimkim, Very Nice,

What sort of range do you think you will get.

Regards
BrettR

[kimchikimkim]

Hi Kimchikimkim, Very Nice,

What sort of range do you think you will get.

Regards
BrettR

I just got another full battery pack from a 2016 Chevy Volt (gen 2 LG Chem based) for only 1k and it had 70k miles. If I can fit it, I'm hoping for 200miles to 250miles.

[DSR-3]

Nice.
That's like double my range on gas, and E85... don't even ask!

[J R Jones]

Tesla love leads to lots of Tesla parts and Valhalla:
https://www.yahoo.com/news/watch-tesla-owner-blow-model-161712290.html

Scandinavian rage = 66lb explosive and overkill.
jim

[kimchikimkim]

Tesla love leads to lots of Tesla parts and Valhalla:
https://www.yahoo.com/news/watch-tesla-owner-blow-model-161712290.html

Scandinavian rage = 66lb explosive and overkill.
jim

I wish he could have let me take the OBC and some of the battery modules before he did that! It really hurts to see someone be so wasteful for views and just blow it up like that.

[dlud]

Actually most of the good stuff was removed from the car before it was blown up. Someone posted on another site all the stuff he was able to pull off the car. He tried to convince the owner to let him have/buy the car but he was insistent on blowing it up. https://www.diyelectriccar.com/threads/full-tesla-model-s-swap-to-mercedes-benz-g-class-w463.205360/#post-1081208

[Bob_n_Cincy]

Actually most of the good stuff was removed from the car before it was blown up. Someone posted on another site all the stuff he was able to pull off the car. He tried to convince the owner to let him have/buy the car but he was insistent on blowing it up. https://www.diyelectriccar.com/threads/full-tesla-model-s-swap-to-mercedes-benz-g-class-w463.205360/#post-1081208

If they would have blown up the battery pack. There would be an enviomental mess. Burning Lithium-Ion batteries give off Tixic Fluoride gas. https://www.nature.com/articles/s41598-017-09784-z

[J R Jones]

If they would have blown up the battery pack. There would be an enviomental mess. Burning Lithium-Ion batteries give off Tixic Fluoride gas. https://www.nature.com/articles/s41598-017-09784-z

I did contract development engineering for a popular tool manufacturer, specializing in battery power. I discovered a technical program about Lithium-Ion batteries on PBS and brought it to the department manager. He ignored it.
https://www.pbs.org/video/nova-search-super-battery/

Nonetheless the battery lab had run-away fire incidents four times while I was there. The building evacuated to the parking lot and the fire department did their job. The rate of conflagration and temperatures were unreal.
PBS/Nova covered future battery technology that is safer.
jim

[kimchikimkim]

Update:

I have mounted all the batteries in the car! I'm ordering a bunch of parts to start to wire up the car.

I have changed direction with what onboard charger I am using after picking up a tesla Gen 2 OBC on eBay for $225. This will facilitate 10kw of charging power meaning I can charge the car in about 6 hours off a Level 2 EVSE. I need to figure out how the internal CAN bus works on it but looks like most of the CAN messages are available on open inverter forums.

On the downside, this project is going over budget so I will likely have to start to rethink a lot of design decisions and sell some of the parts I currently have! I still have the full set of WRX spindles, brake calipers as well as a lower control arm and linkages so if anyone Is looking for some I would be more than happy to sell them off.

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[J R Jones]

Kim3, That is a lot of battery. What is the total battery weight? Have you measured corner weight and predicted suspension spring rates?
I assume they can be removed easily for service access?
jim

[mikeinatlanta]

Yeah exactly. That being said I don't think the brakes will be doing much as regen should take care of most of the braking 90% of the time. That's the main reason I went with VHT, it is rated for higher temps than a powered coat at the cost of a surface that isn't nearly as durable. If it starts to give me problems down the road I will fix them but for now, I will keep them as is.

Awesome project. A bit of advice on the VHT. It will only meet the ratings and be tough/chemical resistant if it goes through the heat cycles mentioned on the can. A long bake at lower temp will work as well. IMO better than powder after the heat cycles.

[kimchikimkim]

Awesome project. A bit of advice on the VHT. It will only meet the ratings and be tough/chemical resistant if it goes through the heat cycles mentioned on the can. A long bake at lower temp will work as well. IMO better than powder after the heat cycles.

Yeah I threw them in the oven. I appreciate the reminder though.

[kimchikimkim]

Kim3, That is a lot of battery. What is the total battery weight? Have you measured corner weight and predicted suspension spring rates?
I assume they can be removed easily for service access?
jim


I haven’t even thought about that stuff yet I’m so deep into the electronics that I’m holding all of this stuff for later. Batteries should be about 950ish pounds alone.

Each Chevy spark Ev gen 2 module is approx 53 lb

And for they aren’t super easy to take out but realistically they won’t be removed much

[kimchikimkim]

UPDATE:

I went to the local wrecking yard today and picked up a CCS Charge port from a Chevy BOLT EV. I plan on adding CCS combo support down the road but will use it for J1772 for now. I paid $200 for the port and the HVJB ( a snag considering how expensive the ports alone are from other sellers. I was super tempted to pick up the QAC7000 greenphy module (part K190) that handles all of the PLC for EVSE signaling in DIN 70121 or maybe ISO 15118 (haven't looked into it super deep yet) but passed since I wasnt trying to push my luck with the auto wrecker.

I took apart the HVJB and noticed that they have an opto-isolated HV present circuit using a resistor divider powered by a TI isolator IC. This is super similar to the same voltage sense found in the BMW i3 Fast charging "KLE" module meaning I might be able to use this circuit in a similar sense with the LIM which CAN DBC is already hacked for me! For Christmas, my parents got me a Saleae Logic 8! If I end up going back to the junkyard I will take the K190 PLC module and hook it up via serial to my logic analyzer and see if I can decipher anything.

I also mounted the DC/DC Converter and started plumbing up the front batteries, DC/DC, etc.....

I am waiting on the HV traction cable from IGUS. I asked for a sponsorship for some 2/0 chainflex cable which is super high quality and shielded so I'm waiting on a response. With so much current going through these wires shielding is a must for signal integrity of low voltage harnesses! It would be close to $450 in HV cabling alone so if I can get it for free it would really help the budget.

On a side note, if I'm not updating as much it's because of a busy week in school coming up.

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[kimchikimkim]

UPDATE:

I got the sponsorship through the Igus young engineers support program. They sent me over $500 in HV traction cable and I am super thankful for it.

I also landed a sponsorship with Alphacool in Germany for radiators, low-power d5 pumps, and really nice delrin/glass reservoirs. I will be using 10x 420mm aluminum radiators from them to cool everything in the car. It should be overkill which is definitely not a bad thing considering the AC induction motors' tendency for the rotor to get pretty toasty due to rotor currents!

I worked on the drive unit contactor box and have a pretty good idea of how it's going to look (photo below). This box will contain only stuff related to driving the motor. Sadly the wrecking yard where I bought the non economized GV200 contactors decided to use an impact wrench on them and the underside of the stud threads is busted so I need to buy new contactors. This time I'm just getting GV200MA's new since I don't want to deal with creating my own coil economizer and transient expression system.

I am using a Rincon Power 400a service disconnect which is going to reside in the center column between the seats. This will be the main HV junction box that each set of batteries will lead up to. Since I have 3 "sets" of 96s groups of batteries I will have 3 leads going into it. On the output side, I will have a lead for the charging box, and another for other high voltage systems (such as PTC heater, AC compressor, DC/DC Converter, etc...)

That's all for now.

On a side note, I decided to take a little bit of a break and make some money by buying a Nissan leaf 2011 with 75k miles on craigslist. I paid $550 for it and tore the whole thing down today. I plan on keeping parts but pick n pull will give me $475 for the shell so it's basically a no-brainer. It's pretty interesting but the battery pack but terribly designed (no active thermal management). No clue what the Nissan engineers were thinking but clearly not much....... I'm going to test the battery pack's capacity (I'm praying that it is good). There is a boatload of parts that I will use to upgrade the first electric car that I built in 2016. I plan on using the motor, inverter, and DC/DC converter to make my Locost a serious rocketship. If the battery pack is good I will use that too (and I will design a forced-air cooling system for it as well). I've gotten a little too sucked into the 818 project so stepping away for a few days has been really good for me! ​

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[kimchikimkim]

UPDATE

I got my hands on a Prius electric power steering column at pick-n-pull (I also got an inverter from a gen 3). If anyone is looking for cheap inverters the Prius gen 3 inverter is absolutely beans cheap for what it is. It was $51 for the inverter and $42 for the steering column + control module that goes with it. The column uses the same spline as the Subaru rack I got off my donor, Perfect! I just cut up the console spaceframe up to get the epas motor to fit. I plan on adding CAN control on the column but I need to use my logic analyzer to look into how the control module communicates with the rest of the car. I've been asking all of my friends but none of them have a Prius with the same year as the donor I got it out of. Just another tangent to go down....

I got the Prius inverter working with an open inverter custom logic board to generate PWM for the IGBT drivers. This inverter will have both of its motor outputs parallel for more current handling since I'm not going to use the synergy hybrid drive. This stack will go in the first car since the leaf inverter is far too big to fit.

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[Ajzride]

You probably don’t need to control the EPAS unit, limp mode should be about right for an 818. We use them in classic mustangs all the time in limp mode and it’s perfect. A 65 mustang is about the same weight and track width as an 818.

[J R Jones]

You probably don’t need to control the EPAS unit, limp mode should be about right for an 818. We use them in classic mustangs all the time in limp mode and it’s perfect. A 65 mustang is about the same weight and track width as an 818.

A, My 1965 SCCA GT350 Shelby B Production spec weight was 2700lb + or - a tolerance. Based on Kim3's battery weight comments I predict his 818 will weigh more.
I had my first drive by wire steering experience in a 2010 Acura TL SH AWD. It was wonderful until I pushed it to understeer. Setting up for a high speed left hander onto a freeway entrance ramp the steering felt routinely great, but the front tires did not, they were sliding on the wet pavement. If you prefer genuine feedback, drive by wire does not provide it.
jim

[kimchikimkim]

UPDATE

Got the Tesla gen 2 OBC (onboard charger) mounted in the vehicle! I probably spent 4 hours drawing up ideas for where to mount the charger but I'm pretty happy with what I ended up with. A big part of its location is the fact that the gen 2 charger is not weatherproofed (as it sits under the rear seats in a model s. I don't have room under seats and I didn't have enough money to get a waterproof enclosure so it basically had to be mounted in the interior of the car.

The Igus cable came in the mail today. Super high quality and the RAAL 2004 looks super nice brand new! Both SKUs of cable I got are fully shielded.

Starting to fab up the emergency HV disconnect mount. I'm making this super overbuilt as the last thing I want is dangling HV.

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[kimchikimkim]

You probably don’t need to control the EPAS unit, limp mode should be about right for an 818. We use them in classic mustangs all the time in limp mode and it’s perfect. A 65 mustang is about the same weight and track width as an 818.

I'm pretty sure I don't have one with failsafe when CAN isn't present. Also, for my application I want to be able to adjust the column assist strength.

[kimchikimkim]

UPDATE

I've been working on the car steadily since the last post.

I had to completely redesign the BMS system due to a major oversight. This has been a HUGE roadblock in the project so far as I have had to learn a lot to just get the boards ordered. I've had to design my own BMS based on the ZEVA EVMS V3 system. I finalized the Gerbers and sent them off to get partially populated at JLCPCB. I have so much soldering ahead of me it's no joke lol. I am by no means an electrical engineer so it took a while to understand how to use EAGLE EDA and modify the boards for my purpose.

Because I will have a total of 288 cells to monitor, I had to change the microcontrollers to ones with larger flash capacities and redo the embedded code architecture to read all of these cells on the bus. The way the BMS works is it uses LTC6802-2 ICs to do the cell management, then it uses an ATMEGA32M1 in my case to take the isolated SPI and throw it on the CAN Bus via a Texas instruments CAN transceiver! Pretty simple from an electronics standpoint but the code behind it is far from simple.

I decided to move to CAD for a lot of the high voltage subsystems since I'm routing cabling. I'm using EMI mitigation guidelines to keep logic-level signals from picking up on interference from the traction battery cables which is a huge headache.

I'm also thinking about getting another 3d printer since my Prusa is running 24/7 and I need to print a boatload more parts.


too many projects too little time.

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[kimchikimkim]

UPDATE

It's been a while since I made an update since I had a lot of reading and learning to do. I am working on making a custom BMS solution since I am working with a total of 288 cells. A few weeks ago I started by taking the reference designs of the ZEVA BMS system and tweaking the boards to work with components that are still in production and work with my use case. I also rewrote firmware to increase the amount of BMS modules supported by the system. Just to be safe, I increased the flash size of all microcontrollers using pin-compatible ATmega64m1. I'm not a programmer by any means so it took weeks to understand both how the IDE works and how to use the chips. Since some of the parts were not stocked by the PCB/PnP manufacturer, I had to hand solder a ton of microcontrollers including the LTC6802-2 BMS IC. Finally have some good news to share after all that pain-the all 12 BMS slave units are spitting out respective CAN frames! I will be working more on software integration down the road as I need to make a thermal management circuit board to control the battery heater over LIN as well as integrating some sort of Economizer for my flow indexer. Lots more to come, but I am slowing down a lot since this is very new stuff for me. I've barely touched the car since the last update since I have been on my computer so much but I did a bit of work today on the battery thermal management system (almost done plumbing up the water loops).

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[kimchikimkim]

UPDATE

Working on wiring and completely redesigned the High voltage junction box.

I built up the custom driveshafts that adapt the Telsa CV cups to STI spindles I got the cv shafts made by dutchman axles and they cost $630 shipped for the pair (they fit perfectly!)

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Here are some pictures of the work I have done.

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I'm trying to finish the car within the next few months but as I'm learning on the job I'm not sure if that's feasible.

[Bob_n_Cincy]

kimchikimkim
Don't hesitate to ask any questions. In 2010 I did a power distribution box for a port container mover. I also designed BMS hardware and software for using LTC6802 chip.

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[kimchikimkim]

kimchikimkim
Don't hesitate to ask any questions. In 2010 I did a power distribution box for a port container mover. I also designed BMS hardware and software for using LTC6802 chip.

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That BMS looks awesome. The discrete bleed resistor network on your custom BMS is insanely beefy where your parallel groups really unbalanced? How did you deal with isolation fault detection on your build too?

[Bob_n_Cincy]

That BMS looks awesome. The discrete bleed resistor network on your custom BMS is insanely beefy where your parallel groups really unbalanced? How did you deal with isolation fault detection on your build too?

At the time we were running 96 700AH thundersky (winston) batteries. It needed a lot of balancing power.

I design an isolation fault detection circuit board that would measure the voltage Pack+ and chassis ground and also measure between Pack- and chassis ground. I had a resistor array on the board to adjust the sensitivity of the circuit.
Dealing with isolation faults was a big problem with our trucks. In southern California, it was not a problem. But running our trucks in Michigan winters there was salt spray that would get into the battery packs. The salt would dry on the cells and leave invisible conductive tracks.

[kimchikimkim]

UPDATE

Working on the cooling system right now. I had to buy new seats since the NRG ones I got were too wide to center the steering wheel properly. Since I am using a Prius EPAS column, I needed to redo the mounting system for the WRX column. I'm pretty happy how it ended up but since I am using the stock AT Subaru pedal box (that is really wide compared to the manual one, I needed to hack it up to make the u-joint fit. Even with this mod I still can't center the wheel perfectly in line with the driver seat space so I ended up getting some Kirkey Seats. Although they were expensive they were much thinner in x y and z so I'm definitely going to enjoy the extra legroom as well as the ability to offset them inwards to be centered with the steering wheel.

After the cooling system is tested in a vacuum I will proceed to fill both the power electronics loop (with G48) and the battery loop (deionized dexcool). I'm hoping to be able to fire up the motor then and get my VIN! A bunch of features that I want on the car are being skipped right now in the interest of time such as the battery conditioner logic as well as a majority of the CAN bus system including the BMS integration with an ECU that I will have to design down the road.

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[Dave 53]

That BMS looks awesome. The discrete bleed resistor network on your custom BMS is insanely beefy where your parallel groups really unbalanced? How did you deal with isolation fault detection on your build too?


If the parallel groups are unbalanced, try a series counter phase rheostat coupler. Isolation fault detection is best delt with by installing a class 3 micro incapacitator linear inspection gauge.

[Bob_n_Cincy]

If the parallel groups are unbalanced, try a series counter phase rheostat coupler. Isolation fault detection is best delt with by installing a class 3 micro incapacitator linear inspection gauge.

Hey Dave, you have been watching too many Turbo Encabulator videos.


https://www.youtube.com/watch?v=Ac7G7xOG2Ag

[kimchikimkim]

UPDATE

The motor is finally spinning. I cleaned up the harness I made and plasma cut out a temporary key switch to gokart around.166480

[kimchikimkim]

UPDATE

I got a VIN! Luckily the CHP didn't care much for body panels and just riveted on the VIN no problem.

I've been really quite since I'm diving really deep into embedded systems coding. I decided to redo the BMS system and instead leveraging chevy volt gen 1 BMS modules (since the CAN network is completely reversed engineered). I bought most of the LTC6802-2 ICs on eBay and lets just say that some of them have some pretty wack mem register values when reading cell voltages. I have 3 months before college starts so realistically I don't think I can finish with how much more I have to learn in the coding department. I'm now using a TMS570 MCU with 4 CAN peripherals. Its a really cool chip that has dedicated ECC memory for each CAN message box as well as super robust watchdog/hardware level clock protection. CCS and HALcogen is still super confusing to me so don't expect any sort of serious leap forwards anytime soon haha.

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[FFRWRX]

You're going to need one of these for your car:

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https://www.etsy.com/ca/listing/1235112804/electric-car-custom-badges?click_key=cfac6e9d186de44d93f76194bc12b4270 f0061e6%3A1235112804&click_sum=9ceed9ec&ref=hp_rv-2&frs=1&sts=1

[fletch]

UPDATE

I got a VIN!


OK. I'm jealous.
But seriously, congratulations. That's an amazing accomplishment, especially since you're building an electric 818. Well done! And good luck at college. I'm sure you will do just fine!

[kimchikimkim]

Update

Well I couldn't say no to a deal on a Chevy BOLT 2020 battery pack and basically I'm starting from scratch. I scored a full chevy bolt battery pack for $3.5k with only 6K miles! This car was literally brand new. I pulled out all of the battery modules in the car now and I sold some of them on craigslist. I was actually able to offset the cost of the new battery and pocket $500 in profits on top of that by selling only 2/3 of the cars original pack! I tore the battery down to module level and am designing a new thermal management system. This battery has a volumetric energy density and a gravimetric energy weight density that is 50% better than the volt pack so it will save around 600lbs off the entire car while giving me 10kwh extra of range (I'm looking to closer to 280miles now abt 66kwh in total!) They are a pain in the *** to package though since they require me designing a custom cold plate and a bunch of other custom bracketry/boxes to house them. I've spent the past few days modeling everything in Solidworks I really want to do this right so I'm doing flow sim on the coldplate to make sure that I am able to dissipate more than enough heat given a typical delta T of coldplate/cell. This is a ton of work but I as nearly everything I'm doing is teaching me more and more about engineering, I am more than willing to go the long route and end up saving money in the end.

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[kimchikimkim]

UPDATE

The car is mostly reworked with the new battery setup. Since I knew exactly what was going into the car and I recently bought a cnc plasma cutting table I headed straight to CAD for everything. I'm pretty happy how it turned out! I just took it around the block today for a drive and it was absurd how much power this thing had. The whole time I was barely touching the throttle

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[kimchikimkim]

Its been a while since I updated.

I have decided to make my own ECU for the car which has taken me a while to design and layout but here is a board shot of it in EDA.

I sent off the Gerbers yesterday and will be developing firmware for it as soon as it comes in. It will be inc charge of every can bus network on the car and I plan on using it to even control DCFC through the implementation of CHAdeMO and hopefully, the CCS LIM now that the CAN bus messages have been decoded (thank you Damien Macguire)

some quick specs of it:

µC: NXP ARM CORTEX-M7 MIMXRT1062 @ 600mhz Core

Input Vdc: 5v-40v

5v 3a Switch Mode PSU

2x CAN 2.0B+ 1x CANFD Interfaces

8x isolated 12v Digital Inputs

8x Smart High-side driver outputs

1x Low-side driver

2x TE Connectivity 23 Pin AMP SEAL connectors

2x 5v PWM

2x 12v PWM

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[kimchikimkim]

The PCBs arrived and I assembled 2 up. Found that I didn't set up some trace DRCs correctly and one of my nets was linked incorrectly but that's life. A botch wire and some soldering later confirms that the switch mode power supply I designed works flawlessly!

I have a lot of coding now ahead of me!

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[kimchikimkim]

UPDATE

I got a really really overkill pre-charge setup that measures voltage rise time on the dc link caps and only closes contactors when the voltage differentials past the contactors are acceptable. I also am able to directly control the tesla motor to change drive modes and also am working on emulating the entire car to control things such a "range mode" and "ludicrous mode" I think I know enough now to control the entirety of the cars drive system.

Im currently working on making another wiring harness to integrate the VCU in the car.

[kimchikimkim]

UPDATE (Big one)

The car is working! (I still need to polish up the code running the charger in the car (a lot of it is not based on ISRs so it's a basic loop that is definitely janky))

The car drives, stops, regens, and charges (only AC charging up to 10kw)

I'm going to shift my attention over to starting to add body panels to the car since most of the basic functions of the car work.

Here is a picture of it as of now. I redid the entire wiring harness in the car. Progress has been a little slow due to school but I'm still moving forward little by little every day!

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[kimchikimkim]

UPDATE

I've fallen off the deep end with all these embedded systems but I figured it would be worth sharing my latest creation for the car. It's a custom ECU and custom HV precharger

These little PCBs have taken me way more time than I want to admit to design and layout but don't worry I'm still working on the car!

I'm a bit of a rookie in the electrical engineering space so the time to completion on all of this is very TBD.


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[kimchikimkim]

UPDATE

Don't worry guys I'm still at it!

I just recently started a company so that has been taking up a bunch of time but I still am working on the car!

Everything is working and it just needs some glass to seal it up. I think after I button it up I'm going to sell it! I love learning through building and this project is about finished so its time to take on another challenge. If anyone is interested feel free to pm me!

Here is a picture of where I am right now.

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