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Discussion Starter · #1 ·
I would like to add electric drive train capability to my '54 Chevy 3/4 ton, without removing the ICE drivetrain. Goal is fun driving around town (not freeway), limited distances, moderate speeds, while still preserving the historical drive train, which I would fire up a few times a year just to keep fluids circulating, seals wet, etc. Not my every day driver, but fun for short trips in fair weather to the grocery store, hardware store, school dropoff and pickup, little league games, etc. Range needed likely under 40 miles. Ideally I could pull over and switch from EV to ICE, but I'm also okay with an hour or two under the hood or under the truck to manually covert over from legacy drive train to electric and back a few times a year. Is there any logic to considering a pair of front wheel drive motors, leaving the ICE drive train in neutral with engine off when driving EV? Tons of room under the truck bed for motors, batteries, controllers, transfer cases, etc. Ideally not butchering the truck so it could be a clean ICE-only again some day. Though not a garage queen by any means. Goal is fun, educational project with my 8yo. Comfortable rebuilding engines, soldering, programming, general construction skills, and just now getting in to welding. Years of RC model flight so quite comfortable with batteries, DIY controllers, software, firmware, chargers, wiring, etc. Also just PV'd three homes, so I now know my way around PV, inverters, RSD, large (expensive) lithium batteries, etc. Welcome any suggestions such as "buy a wrecked Leaf" or "buy an EV West kit" or "take the DIY class in Anderson, CA". Only a few hours into the research, and have only owned the truck for a year. Project budget? Ideally $10k. Paid $15k for the truck, so wouldn't want to spend much more than low teens all in for EV project, with plenty of DIY hours expected. Welcome any suggestions. Bay Area based. And hey, why not have several fold-out PV panels on a classic wood fence in the truck bed? I know two to four 360W panels isn't going to do much, but if the truck is driven < 1 hour a week, and the sun here shines 60 hours a week, why not? Thanks for any guidance.

121382
 

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Discussion Starter · #2 ·
Forgot to mention the legacy drive train is a dual-carb 236ci inline 6 paired with a stock 4 speed manual transmission. 2WD. Truck is quite stock throughout (other than the dbl barrel carb), and went through a down-to-the-frame 12 year restoration by previous owner.
 

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You could make an electric motor mount (with reduction unit if needed - you can get a motor with a Chevy driveshaft spline from EV West that I recall if you really want to keep it simple and most driveshaft shops can chop a shaft for you and adapt drive yokes) midships and run a short driveshaft. Plug and play battery pack in the bed, with a faux bed on top of the pack that doubles as weather resistance, that you can hoist/forklift out.

That way you can have stupid dead iron in the front for running electric and not wreck the truck apart from the removable crossmember that mounted the electric drive. Might have to beef the rear springs and shocks, as half tons tend to go nose vertical when the bed's loaded. From what you describe, around 500lb of battery will be fine.

You'll also need to cap off the tailshaft of the ICE transmission when running around electric. Easily 3d printed.

You should be able to do this back and forth reconfiguration in less than four hours if you design it to be reconfigurable. Bonus in doing this is you can run the ICE now and then, including running the trans through the gears, to keep corrosion out of them.

A lot of hours in that truck so would be a shame to butcher it. My dad had a '53 I grew up in...I cried for two days when he sold it (I was 11).
 

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Discussion Starter · #4 · (Edited)
Thanks Remy. Great suggestions. I like the ability to periodically run the ICE drive train from carb intake through tranny output, independent of electric drive train. And reversibility of implant / lack of scarring is important. A few holes/welds on the rails for the mid span motor mount is not a big deal to me. Re 500# of chemistry to make it all go, would you DIY that? What base cell, and voltage, etc.? I can easily imagine four anchor points that I use overhead block and tackle to remove/add the pack with. Lastly, is there a car in particular that would be a good donor for this project, or am I better off just picking up the best motor, controller, charger, etc? In a conversion like this, would you fit the controller input to gas pedal, while still leaving pedal-to-cable-to-carbs-linkage in place? And where would charging point go? Rear?

BTW, it's a 3/4 ton, not 1/2 ton. 8 bolt wheels. Not averse to beefing up springs and shocks, but not sure I'll need to.

EDIT: How can I determine if I need gear reduction? I can calc RPM of drive shaft and wheels at ~40mph desired top end. Not planning on pulling stumps in 1st gear, so low end torque not a key objective either. All ears on this one.
 

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To avoid really awkward mode changes, it would make sense to me to treat this like a parallel hybrid conversion, even if you never run both power sources at the same time. The easiest way to do that is to insert an electric motor between the transmission and the last section of propeller shaft to the axle.

It might make sense to use an induction motor, because they spin freely when not powered.

A 3/4 ton truck with parallel hybrid conversion using an induction motor has been done commercially. If I find a link, I'll post it.
 

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The parallel hybrid truck system I was think of was the Balance hybrid by Azure Dynamics, available initially on the E-450 and later on the F-450 (both of which are much heavier than a 3/4 ton).
 

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Discussion Starter · #7 ·
Thanks Brian. I searched Azure Dynamics Balance hybrid. Sounds like they went BK in 2012.

You said "insert an electric motor between the transmission and the last section of propeller shaft to the axle". Is propeller shaft the same as drive shaft? Internet makes me think so.

If I didn't mind the explicit mode change once or twice a year, and it seems Tesla 3 or Nissan Leaf or Prius are the best donor platforms to start with. Apologies for my ignorance as I'm only a few days into researching this project and the EV conversion space, but is your suggested induction motor inline with tranny and drive shaft possible with one of those mainstream OEM platforms?

Also, anyone know the ballpark dimension of the Leaf battery modules? Wanting to start measuring under bed vs in bed with false floor above. My instinct is there is a ton of room beneath the bed. But I don't know if exposure to road elements is a significant consideration in the over/under debate.
 

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Yeah - you can also do what Brian suggested, but it means a fair bit more fab work and design effort.

Now you need to support the driveshaft yoke with bearings, lube them, incorporate a pulley or gear (which arguably you need anyway - my rule of thumb is to run the motor at 80% of its rated RPM to get around 3000 RPM at the driveshaft 2:1 to 3:1 usually. If you don't do this, you're throwing away half the HP and half the torque -- many people live with that and don't do the reduction, which was what I mentioned with the EV West Chevy driveshaft output motor) and have the ability for the original trans to run power through to your reducer-speeded output shaft.

My opinion is once you go electric, you won't want to go back to ICE, though, which means you'll convert it to electric once, then back when you sell it. So, in reality, you're still swapping hardware the same number of times. I still remember where the gas tank was in those - would be nice to ditch that one if you're not into self-immolation.

I also would AVOID any welding if possible and use existing frame holes if you can.
 

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How about one of the newer high voltage alternator motor some of the new cars have? If you can live with < 40horse in the city.
 

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Discussion Starter · #10 ·
Thanks all for feedback. Tentative decisions:
  • Going with a Tesla 3 or Prius or Leaf. Arguments made in various places about volume and quality of OEM EV drivetrains are compelling. Plus ready availability of used donor vehicles, especially in California.
  • Open to pro's/con's/guidance as to which donor platform. From what I've learned over the last few days, it seems to be a choice between cost, horsepower, battery size/config/ease, and openness or lack thereof on controller and other system components (Tesla being the least open?). I covet the HP of the Tesla 3, and not afraid of dealing with battery coolant system, but if all that costs twice as much as a perfectly good Leaf or Prius platform, and the latter are more open, then maybe I should go Japanese. I like open source, having played in the custom firmware builds for ArduPilot (open source flight controls), and not averse at all to rolling up those sleeves.
  • Fine with a electric-only install, with ability to occasionally manually toggle between ICE and EV with a few hours of wrench time. Though if a quality EV implementation with the appropriate gear reduction is 90% of the effort of a quality hybrid install, then I should go hybrid. Just to clarify, a hybrid install would fix a gear on the drive shaft, mid shaft, and drive that from EV motor via belt/chain/pinion? And that system is happy idling if truck driven by ICE engine+tranny?
  • Agree self-immolation is not a goal, and gas tank behind seats will be emptied, possibly removed. If pure EV and not hybrid, periodic ICE turnover once a quarter will be with temp fuel container with hood open, warming up ICE, running through the gears (tranny disconnected from drive shaft), just to circulate fluids, keep seals wet, corrosion at bay.
  • Battery location: over bed or under bed? And/or perhaps behind seat if I decide to remove gas tank?
  • Is 4WD some day out of the question? That may be a fantasy not worth it, especially if I want to leave ICE drivetrain installed. Curious what more experienced automotive minds than mine think about putting EV 4WD on an ICE 2WD truck that never had it.
 

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I searched Azure Dynamics Balance hybrid. Sounds like they went BK in 2012.
Yes, Azure Dynamics went under - as all EV conversion companies eventually do. Bits from their liquidation inventory are still found for sale. I wasn't suggesting them as a conversion vendor, only using their Balance hybrid as an illustration of a possible configuration.

You said "insert an electric motor between the transmission and the last section of propeller shaft to the axle". Is propeller shaft the same as drive shaft? Internet makes me think so.
Yes, "propeller shaft" means the drive shaft from transmission to axle; it's just a more specific technical term to identify the correct shaft.

If I didn't mind the explicit mode change once or twice a year, and it seems Tesla 3 or Nissan Leaf or Prius are the best donor platforms to start with. Apologies for my ignorance as I'm only a few days into researching this project and the EV conversion space, but is your suggested induction motor inline with tranny and drive shaft possible with one of those mainstream OEM platforms?
The motor in the Balance design has a double-ended shaft, so it becomes part of the propeller shaft. Unfortunately that means that it runs at propeller shaft speed, so you need a big motor to deliver enough torque with only the rear axle gearing.

The alternative to the through-shaft motor is a motor with reduction drive (gear, chain, or belt) - that's more complex, and there's a lack of off-the-shelf bits to use for this. Unfortunately, most reasonable EV motors can run a few times as fast as the propeller shaft, and as remy martian points out you need gearing to make the best use of them. EV motors all come in the cars with a reduction gearbox attached, but that's a transaxle with an unwanted differential and too much gear reduction to use in addition to the ratio of the rear axle. So...
  • yes, you can use some production EV parts, such as motors, controllers, batteries, and supporting electronics, but
  • no, production OEM drive units (motor with transaxle) are not generally usable directly as an inline additional motor.

There is one slightly obscure possibility...
  1. any common drive unit could be turned 90 degrees around a vertical axis so the axle outputs face forward and rearward
  2. the differential could be replaced by a spool (e.g. Quaife Tesla Model S Spool Differential – Large Unit) so that the axle outputs turn together
  3. a first section of propeller shaft could be connected between the truck's transmission output and one axle "output" (using output flanges for the drive unit as required)
  4. the rear section of propeller shaft could be connected between the other axle output and the rear axle
  5. if this is done with a Tesla Model S large drive unit the gearing could be changed with the Tesla Large Drive Unit Gear Set 4.5:1
The overall result looks like what some people have done to convert Land Rovers to electric, with the Tesla drive unit replacing the engine, transmission, and transfer case; however, in this case the two shafts would be passing engine and transmission output through the electric drive unit, instead of taking electric drive unit forward and rearward to the axles. The cost is huge if you need to use all parts from supplier such as I have linked; a more moderately priced solution may be possible for builders who are able to fabricate parts themselves, but making custom gearing is generally not a DIY task.

As remy_martian noted, the mechanical bits here are far from trivial. The motor with double-ended shaft is by far the simplest, and straightforward to implement... if you an find a motor which will produce enough power at the low speed of the propeller shaft.

Also, anyone know the ballpark dimension of the Leaf battery modules?
Just Google search "Leaf battery module dimensions"... you might be surprised how much detail is available. In anything other than the new 62 kWh battery there are 48 identical modules, which come glued together in pairs in most variants.

Wanting to start measuring under bed vs in bed with false floor above. My instinct is there is a ton of room beneath the bed. But I don't know if exposure to road elements is a significant consideration in the over/under debate.
There is not a lot of space for battery. You may think so, and it looks like that at first glance, but fit a motor and controller under there, and considered that battery modules are absolutely inflexible boxes, and you'll realize that there really isn't much space. It's a challenge when doing a conversion which removes the original powertrain; doing with the engine and even the fuel tank still in place is a creative shoehorn exercise.
 

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How about one of the newer high voltage alternator motor some of the new cars have? If you can live with < 40horse in the city.
I assume that you're talking about the alternator/starter/hybrid machines used in "mild hybrids" such as FCA's eTorque system available in Ram trucks and some Jeeps. They're normally connected by belt to the engine, so are never used to propel the vehicle by themselves, and they're too low in power to be useful as an electric-only drive. The V6 version of eTorque is only capable of 12 horsepower (at the 48 volts used in that system).
 

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My immediate thought was along the same path as brian_, but I've been watching a few of Damiens videos lately, and I think this would be a fairly reasonable place to put a Lexus hybrid transmission in place of the 4 speed manual.
The Lexus hybrid transmission has a motor that drives the propshaft, and a generator spun by the engine (which Damien uses as another motor by locking the input shaft to the housing). In the Lexus, pure EV mode is a bit limited, though.
MG1 as a generator necessarily need to handle half the ICE output power (and torque), otherwise that power (and torque) would just be lost and never reach the wheels. MG2 as a motor has to take in the power from MG1 and convert it back to mechanical power, plus the added 20kW from the battery. So MG1 regularly handles between 100 and 150kW, while MG2 handles a bit more.

I know, it would be a bit of unexplored terrain, because Damiens project doesn't support having the engine in there and the Lexus originally uses the boost converter, limiting the battery current. Damien uses the boost converter as a charger instead, or to drive a DC-DC converter. But just having MG1 spinning freely in regular use, spinning it up to start the ICE if wanted and using it as a generator to charge battery from ICE power are all doable even if the eCVT mode probably requires the boost converter to separate the battery voltage from the working voltage of the generator/motor dynamic. How it behaves if the boost converter is bypassed and the DC bus is limited to the battery voltage is an unknown. But a very interesting unknown.

The good news is that mechanically, this is MUCH simpler than any other solution. And electrically, we're talking a bit of custom firmware in a logic board that Damien has already made, just to use MG1 as a generator and starter instead of a motor. So not that much there either.
 
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