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Discussion Starter · #1 ·
Well, the project is not done (will it ever be?) but I feel like I have moved into a new phase. I drove up to the shop today to work on other things, and so I got some good statistics using the datalogging function on the X144 controller. I was a bit confused by the software at first, but I have to say I am liking all the functionality even with many of the parameters locked out by the distributor. There are some parameters on the motor tab, for instance, that I simply do not understand. Not being able to change them is probably for the best.

I have been trying to get my head around the battery voltage, and how it responds to load. My BMS system communicates with the charger, so the charger cannot cause a problem. When driving, if I exceed the BMS settings for High Cell Cutoff or Low Cell Cutoff, it will sound an alarm; but that is all.

So to protect the cells while driving, I need to set up this map in the X144 software:


The Over and Under voltage limits are the values that the controller is to never exceed. I have them set for a multiple of 4.20 and 2.95v/cell respectively. My system is 42s, and all my cells are within 0.008v, so that should never drive a cell outside of the max values. I am cutting off my charge when the cells get to 4.10v, and then they immediately droop back a bit - so even rolling down a big hill right after a full charge should not be a problem.

Points B and C are the values where the controller starts derating. If driving it will enter a limp mode, and if charging with regen, I guess it will just taper off the current. I have not driven it when the cells are low, so I have not really tested any of it yet.

The software lets you select any of the parameters it measures, and store them in a datalog with up to 200ms sampling speed. I plugged in my laptop, told it to record Current, Voltage, RPMs, and Motor and Controller temperature every second. It was about a 10 minute drive, so it made a nice big spreadsheet. Open Office was not happy about trying to make a graph out of all of it. It is interesting data, and does basically what you would expect. I found with big bursts of power (200-300A) I would see about 15 volts of sag.

I decided to take the average of the current and the voltage, and multiply them together, to give me the average power. That should more or less check out, right? I knew my travel time, and my distance, so I came up with some consumption numbers. On the way up to the shop I used an average of 12.2kW, for a total of 2.2kWh and 486 wh/mile. Wow, thats terrible I thought! But, it is uphill the whole way, and gains about 600 feet of elevation. So on the way back? It dropped to 5.8kW, only 1.1kWh, and 244Wh/mile. If I average them, I get 365wh/m which seems ... about right. I am not really sure how much my truck weighs, at some point I will have to venture down the to dump with a load of recycling or something just to use their scale. The battery pack in the Merc b250e was supposed to be about 28kwh, so I should be looking at about 75 miles of range if any of these wild conjectures are accurate.

Anyhow, it feels like a start. I have maybe not built the best DIY electric car ever, but I did build one! It even went 55mph before I chickened out and eased off the throttle. Seriously, with all the carpet and trim gone, and the ancient cheap Chevy-grade plastic rattling around inside, it sounds kinda scary :D
 

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Discussion Starter · #4 ·
Can you link to your BMS? ideally also a trustworthy source
I used a BMS from thunderstruck: Battery Management System
It is simple to set up, although I think the Orion BMS might have more features. Works great to control the charging end of things, and it is nice to have an alarm that sounds. I do not like the idea of having the car shut down if the battery voltage sags too low for a second. Better to set the threshold a little high and have it beep at you so you know to charge or limp home.
 

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Discussion Starter · #5 ·
Well, the truck is doing great electrically, but I am starting to hear noise coming from the transmission! After watching lots of videos on diagnosing the noises, It seems like the pilot bearing is likely the main problem, but I also hear some rattling/whining when I spin up the motor with the clutch engaged and the shifter in neutral. The truck has almost 200k miles, and it would not surprise me if the transmission is due for an overhaul. If I had it to do over again, I would have ponied up a little more money for the donor vehicle. I guess part of me didnt believe I would ever get this thing running, and wanted to cut my losses up front :). It is much to late to back out now, so I think I will probably end up taking it in for service. I was quoted about 1500 bucks to have it refurbished; I might call around and get a second opinion. I did find a few places online where you can buy a refurbished unit for about a grand (shipped and with the core charge), but I do not know how reputable that sort of thing is. I would love to hear any input people would have, as I am clearly not a "car guy."

The pilot bearing that came with the motor adapter did not fit very tight, as I recall. I seem to remember I could just slide it in by hand. I am not sure how I am going to deal with that, but I think the first thing is to get it taken apart and maybe get someone who knows what they are doing to come take a look at it.

I recorded how much power I needed to charge back up to full after driving, and I feel pretty confident in my 350 to 375 watthour/mile figure. I signed up with a charging network that is common around here, and at some point I want to test out if my charger will work with a j1772 system. In theory it should, but I am just bypassing the pilot signal and using a modified extension cord to charge up.
 

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Well, the truck is doing great electrically, but I am starting to hear noise coming from the transmission!
Ah, the dreaded after conversion start of transmission noise! I think it must be a human nature thing where most people immediately blame the transmission for the problem. I mean it couldn't possibly be anything I did! Usually this problem is associated with poor alignment issues. But I think you have that covered by using the usually well designed and made Can EV adaptor set-up. A couple of times I've seen the press-on hubs start to work their way off of the shaft and cause all kinds of mayhem. Usually, this is accompanied by the clutch pedal raising up out of position. Is your hub secured with set screws and maybe with dimples in the motor shaft?

Is there some way to rotate the set-up to feel and listen for any binding? Maybe drop the driveshaft? If your clutch is the lever type, maybe you can pry back the rubber boot around the lever and take a peak inside the bell housing. It might be worth it to borrow or buy one of the new, low cost inspection scopes to have a better look inside.
 

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Discussion Starter · #7 ·
I think it must be a human nature thing where most people immediately blame the transmission for the problem. I mean it couldn't possibly be anything I did!
Well, I did install all of it without knowing exactly what I was doing, so anything that is wrong with it will be my fault, of course. :)

The noise that I believe is coming from the pilot bearing only occurs when the clutch is fully depressed, and goes away as the motor RPM drops off, or the clutch pedal is released. When I drive it, everything sounds okay. Its just that now it squeals when the clutch is depressed, and if I listen to the transmission in neutral when there is no road noise, I can hear what sounds to me like some bearing noise. There is also a tiny leak at the output shaft. I bought the truck for 750 bucks, and it was not operable when I got it, so I have no baseline for what shape the transmission was in.

I will check the hub, but I seriously doubt it has moved. It was heated to 400F and then just dropped onto the shaft with a plunk. Once it cools it locks on with a death-grip. I know this, because I had to take it in to a motor shop to have it pried off when I botched the first try at getting it on right. My little 2 ton pulley puller would not even budge it. I did check the flywheel hub with a dial indicator, and it was within spec for run-out.
 

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Well, I did install all of it without knowing exactly what I was doing, so anything that is wrong with it will be my fault, of course. :)

The noise that I believe is coming from the pilot bearing only occurs when the clutch is fully depressed, and goes away as the motor RPM drops off, or the clutch pedal is released. When I drive it, everything sounds okay. Its just that now it squeals when the clutch is depressed, and if I listen to the transmission in neutral when there is no road noise, I can hear what sounds to me like some bearing noise. There is also a tiny leak at the output shaft. I bought the truck for 750 bucks, and it was not operable when I got it, so I have no baseline for what shape the transmission was in.

I will check the hub, but I seriously doubt it has moved. It was heated to 400F and then just dropped onto the shaft with a plunk. Once it cools it locks on with a death-grip. I know this, because I had to take it in to a motor shop to have it pried off when I botched the first try at getting it on right. My little 2 ton pulley puller would not even budge it. I did check the flywheel hub with a dial indicator, and it was within spec for run-out.
Throwout bearing is bad.
 

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The squeal could be the classic dry and /or worn pilot bushing sound. Did you use a bushing or a needle bearing for a pilot bearing? If the bearing/ bushing was a loose fit in the hub, it would be all right to use some low strength Locktite to hold it in position. I forget from your build postings: did you make sure there was some clearance between the end of the transmission input shaft and the end of the motor shaft, when everything was torqued down? One way to measure this is, if you are not sure, is to put a dab of modeling clay between the ends of the shafts. Torque down the whole set-up, and then take everything apart and measure the thickness of the clay.

The curse of the EV is that they are so quiet, now you hear every noise, vibration, squeal, and bang that was covered-up by the noise of the ICE.
 

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Discussion Starter · #10 ·
Throwout bearing is bad.
Wouldnt the throw-out bearing start to make noise as soon as the clutch pedal began to engage? The noise I am hearing only starts once the pedal is all the way down.

I suppose that if the tip of the transmission shaft was bottoming out in the flywheel adapter, that would cause the noise to occur when the clutch was disengaged; but it doesnt make sense to me why it would not have been making that noise from the start. Anyhow, when I get a chance, I will tear into it and see what it looks like in there.
 

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Discussion Starter · #11 ·
Well, it has been a while... I got way overextended with all my projects, and the truck just got parked. It pained me at first to keep walking past it, and then I just sort of stopped seeing it altogether. Anyway, I am getting caught up on my other priorities, so I have made some time to dig into the truck again.

I got it up on stands, and dropped the transmission out. The winner of the "how did you manage to mess this up?" award is Electro wrks!

I forget from your build postings: did you make sure there was some clearance between the end of the transmission input shaft and the end of the motor shaft, when everything was torqued down?
I did not! As Brian surely remembers, and can likely quote you the day I said it from memory :D - my critical distance was not lining up. The flywheel position had changed relative to the transmission. How critical is the critical distance? Clearly 1mm is not close enough. The pilot shaft had made contact with the hub adapter, and was merrily drilling away at the steel in its free time (Or whenever I pressed the clutch, at any rate). I recall at my first test drive I thought my clutch was sticking, but it had simply not broken free yet.

There was evidence that the shaft tip had heated up, and that caused the pilot bushing to stick to the shaft, so it was just spinning around in its race. The bushing being soft, I do not think it damaged the shaft. I took the transmission in to a shop to have the rest of it looked at, and then my plan is to just file down the shaft by 1mm. I ordered a new pilot bushing, and some special loctite to make sure it stays put.

Anyway, while I have it in the shop I have been working some wrapping up some loose ends. I tested the coolant heater, and the 220v hotwater tank element is working great. It puts out about 1100W at 162 volts. I have a temperature controller that cycles it on and off, trying to get the temp up to 15C. I didnt time it, but it does raise the battery temperature accornding to the BMS. I suspect that in cold weather the heater going and the heat from driving will get them up to temp pretty quickly. I will just have to remember to shut off regen until they have warmed up a bit.

Today I also worked on getting my cab heater sorted out. I used 2x 220v PTC heater elements that I had from another project - and a couple of 12v computer fans. It blows nice hot air, although it smells a little funny. My amp meter says it is drawing 4 amps, so around 600 watts. I am cautiously optimistic.

Once the transmission is back in, I really need to drive it a bit and see how much range I might possibly have. I think having at least a good guess will make me less hesitant to venture out with it.

Little by little adds up to a lot.
 

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Discussion Starter · #14 ·
Well, my truck is back on the road. Getting the transmission out of my truck was not too bad, getting back in was not as easy. The way my motor cradle and adapter plate are laid out, once the transmission is removed, the motor is only hanging on the metal band, and a ratchet strap up front to keep it from simply falling out. After spending a morning trying to cram it back into place, with transmission oil pouring out the back, I almost quit my project for good. After laying on the ground for a little while feeling utterly defeated, I mopped up the oil, and decided that I would have to pull everything out of the engine bay, and connect the motor and trans as a unit and drop it back in with a hoist like the first time. It took me a bit to muster the energy to actually do it, but I managed to get it all out and back in. I also fixed a slow leak in the coolant tank, so I have now checked all the boxes on the EV part of this project.

With the shaft shortened down, there is now no weird noises when I shift. The transmission actually looked good inside, and all it needed was a new rear seal, which stopped it leaking oil. Coolant system is holding fluid, the battery heater is working, and the cab heater actually even managed to keep the window mostly defogged.

I am seeing quite a lot of voltage sag, maybe as much as 15+ volts when I really need a lot of juice to climb a hill. At 3.36v per cell, the sag could get me down to 3.00v, which I am treating as 0% if it is the resting voltage. My understanding is that voltages below 2.7 are bad for these particular cells, so I do not want to drive them too hard and risk damaging them. My BMS will start to beep when any cell hits 3.00v. I would love to hear from other people using Tesla modules on where you are calling the battery "empty." I do not have great instrumentation, so I am going to need to build up some experience with the pack and cell voltages, as well as how quickly they will stabilize after a drive.
 

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What percent of max motor rpm are you running during the hill climbs and how many HP is the motor again?

How much current are you pulling at what pack voltage?

What kind of grade are we talking about and what speed are you running?
 

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Discussion Starter · #17 ·
What percent of max motor rpm are you running during the hill climbs and how many HP is the motor again?
I looked back over my notes, and the time I logged my drive up to the farm, I was running at about 2000 to 3000 rpm when pulling max current. The motor is rated for 120kw peak, and max 8000rpms.

When I accelerate hard, I draw about 350+ amps at around 160v - so about 56kw. I seem to be able to hold about 50mph with 100 to 150 amps on "flat ground" although around here that is just the 50 or so feet at the tops of the hills 😀

Mostly I am cruising at about 40-45, and the big hill that I need to climb is a 6.7degree or ~12% grade that is about 800ft long.

Invest in a tail shaft end cap.
Haha, if I knew that was a thing, I would definitely have done that! I tried the old "rag and a plastic bag" routine they suggested in the chiltons, but that only goes so long before it gets soaked in oil and falls off. God I hate oil.

I lost my shop solar array in a windstorm this winter, but I was able to siphon off a bit of power from my house array today. I got some used panels that I need to get mounted to get my charging capacity back up, but I have learned my lesson on the importance of proper racks. A gust of wind picked up 3 panels, 6 concrete pier blocks, 30 feet of 4x6 and various other lumber and chucked it about 6 feet down an embankment. A loose tarp 20 feet away did not blow away, so I am not sure how exactly that works.
 

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Discussion Starter · #20 ·
Well, I had someone ask about a list of my projects components (sorry it took so long). I had posted part of this in another thread but never in one of my own. Not sure if this info is of any use, but this gives a pretty good overview. There are undoubtedly lots of ways to trim down the cost on a lot of this stuff, and if I was doing it again (and not during the biggest supply chain disruption of the last 70 years) I would probably have thought about buying a used/crashed leaf and stripping it for parts. Even if the battery was basically shot, it would have been cheaper than the motor kit I bought (at least it was before the price of used cars went crazy).

I am still working on range estimates, but the incredibly slow charger and a general lack of free time is making it go pretty slow. If I can get a 220v outlet wired up, I can boost my charging to 2500W at the shop, which would make it go a little faster. I am getting used to all the strange noises that it makes, which is slowly building my confidence that it is not rattling to pieces as I drive. I stripped all the carpet out of the truck because it was nasty from the previous owner smoking in there, and so there is a lot of road noise. I have one-pedal driving set up, so I also get a bit of lurching when the regen is on and the accelerator is right at the threshold between regen and drive. I also had a bit of a scare when my BMS started randomly beeping at me, but I traced it to a faulty thermal probe, and simply deleted it through the software. I did not want to have to dig into the battery pack... The manual steering works great. When I drive around I forget its even manual until I need to make a 90 degree turn, but it is not difficult at all. The whole front suspension could probably use some TLC, and the alignment seems way off, as the car wants to wander towards the nearest ditch. I am going to plan on overhauling all of it at some point; do the brakes too while I am at it.

Anyway, It feels pretty good to have a "functional" EV! I have learned lots on this project, and I am also going to use it as an excuse to get more experience doing "car stuff." I am going to approach it as an opportunity to learn some new skills, and I do genuinely like understanding how the stuff we depend on actually works.
 

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