Planning 1994 Honda Acty conversion!

9396 Views 55 Replies 11 Participants Last post by Acty DCty, 2 mo ago

Acty DCty

Discussion Starter · Apr 22, 2021 (Edited)

Hey, friends! My buddy and I recently decided to try an electric conversion.

We found a working base-model 1994 Honda Acty in a used car lot, and it seemed to be a good fit. Manual transmission, manual steering, manual windows. Light, small frame. Plenty of room for batteries in the pickup bed. Rear wheel drive, right under the batteries.

Neither of us has much experience working with cars, but we used to kit-bash old computer parts together to get them to run operating systems they were never meant to run. We once turned a 1991 Mac LC into a web server. We were looking for a more 21st century engineering challenge, and settled on this. I am quite sure we will screw something up horribly, but that's part of the fun!

For me, the goal is not to make the World's Greatest EV, but to make an EV that starts and stops and does not catch fire.

As far as components we have so far - just the Acty. Everything in it seems to work great. We are researching parts, but thought it was smart to post here before we spent more money.

So, if this were your conversion project - where would you begin?

Please don't judge us for being beginners! We're committed to doing the research, and we don't mind if we fall short. We figure the worst thing that can happen is we ruin a 1994 Honda Acty.

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Electric Land Cruiser

· #21 · Aug 7, 2021

Sepex motors can regen, but it's not the same thing. Sepex motors do not have permanent magnets in them they require a separate field voltage applied. It's really hard if not impossible to find Sepex controllers that work over 60-70 volts or so which is why it piqued my attention.

I'm sure you guys could figure out how to make it work. You could use a separate controller with modified Arduino code possibly.

Here's a good explanation: Sepex Motors explained for dummies (like me) by JohnnieB

Sepex motors are like the modern induction motor of their time but now obsolete except in golf carts. But still quite a few good reasons to use it if you've got it!

Acty DCty

Discussion Starter · #22 · Aug 7, 2021

Hey, thanks for that info! I had been under the impression that SEPEX and regen were the same - that one was necessary to get the other. Looks like we have some reading to do. Appreciate the link especially. Will come back with questions.

brian_

· #23 · Aug 7, 2021

Acty DCty said:
I had been under the impression that SEPEX and regen were the same - that one was necessary to get the other.

Regeneration, which is just running the motor as a generator, is possible with almost every type of electric motor, but the big exceptions are series-wound brushed DC motors: in series motors, the field winding is in series with the stator winding, so it's not possible to separately control the field - you can't "turn on" (excite) the field to make it generate. The controller linked earlier can only handle regen if there is no field winding, specifically in a brushed DC motor with permanents instead of a field winding. A SepEx motor (also called a shunt wired motor) allows separate control of the rotor (armature) and stator (field) current, so it can do regen... if you have a controller with separate armature and field sections, or two controllers which are coordinated as Electric Land Cruiser suggested.

You're off into obscure territory here, which is fine if you want to explore and learn. The vast majority of DIY conversion projects either use brushed DC series-wound motors (so they can't do regen), or use three-phase AC motors (which can all do regen). A few use permanent magnet DC motors (in small sizes); almost none use SepEx motors and it would be hard to find a single example of anyone using a SepEx motor with a custom set of coordinated by separate controllers.

Hopefully that round-up will help in interpreting what you find in your reading.

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Acty DCty

Discussion Starter · #24 · Aug 8, 2021

Fascinating.

We also have the option of just ignoring the SEPEX field and not doing regen, right?

brian_

· #25 · Aug 8, 2021

Acty DCty said:
We also have the option of just ignoring the SEPEX field and not doing regen, right?

Earlier you said that the "has a SEPEX field". Unless it has both a series field and a shunt (SepEx) field... no, you can't just ignore the SepEx field. You need a magnetic field, created by current in some field winding (or by induction which this motor doesn't do, or by permanent magnets which this motor doesn't have).

Acty DCty

Discussion Starter · #26 · Aug 9, 2021

The way it was described to me is that it has 2 series fields and a SepEx field. In the video where we tested it, we got it spinning by just connecting the power to the series fields (ignoring the SepEx). I'll post a picture and label the parts when I get a second.

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Acty DCty

Discussion Starter · #27 · Aug 9, 2021

Photoshop is crashing on my little netbook, so I'm having trouble cropping and labeling a pic. But here's the part of the video where the original owner explained the motor (sorry Brian, I know you don't love videos, but the relevant info is conveyed within 30 seconds or so).

And here's the part where we test the series fields with a 12vdc current, just to make sure the thing wasn't DOA. We didn't hook anything up to the SepEx fields.

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Acty DCty

Discussion Starter · #28 · Aug 11, 2021

Here's a diagram:

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rmay635703

· #29 · Aug 11, 2021

Albeit off topic a Nissan Leaf motor has a 7/8” 20 count slip fit spline, Many Honda’s including the ACTY (depends on age can be 18 or 19 as well)
can have this same spline count on the transmission meaning you just need an adapter for the mounting face of the Nissan to mount up when the spline matches

brian_

· #30 · Aug 11, 2021

Acty DCty said:
Here's a diagram:

View attachment 123299

"Field" in this context means the stator winding(s), so the group labelled as "Connectors for main field" are actually

the armature (rotor) connections (A1 and A2), and
the series field (stator) connections (S1 and S2)

Acty DCty

Discussion Starter · #31 · Aug 12, 2021

Thanks for clarifying! Still learning the terms for everything. Read a paper today about sepex fields and my brain leaked out my ears.

We opened up the motor and cleaned it, by the way. It was pretty heavily used. Should be in better shape now.

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Acty DCty

Discussion Starter · #32 · Aug 29, 2021

What adhesive do you folks use to attach two small pieces of plastic together? The piece is too small to drill holes in, and various forms of glues have failed us.

Electric Land Cruiser

· #33 · Aug 29, 2021

This stuff is my go-to for that, chemically bonds to plastics and also fills gaps, reinforces, etc: https://amzn.to/3ymb26Y

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brian_

· #34 · Aug 30, 2021

Acty DCty said:
What adhesive do you folks use to attach two small pieces of plastic together? The piece is too small to drill holes in, and various forms of glues have failed us.

Adhesives work poorly on polymers in general, but exactly which polymer is very important. For instance, even the Permatex Permapoxy Black Plastic Weld suggested above works for many polymers, but Permatex says that it "will not bond polyethylene and polypropylene plastics". For some polymers, solvent bonding is the practical solution - that's how ABS and PVC pipes are joined.

Acty DCty

Discussion Starter · #35 · Nov 18, 2021

We're finishing up our circuit diagram!

We are building an EV system with 96VDC, 100A. We have this controller. Anyone got any idea what specifications the precharge relay should have?

Acty DCty

Discussion Starter · #36 · Dec 30, 2021

We've got a bunch of new parts, including a Daly BMS for LiFePO4 batteries that meets our specs, and our full set of batteries.

We also cleaned and rebuilt our motor, built a heat sink for our controller, tested our potentiometer pedal, replaced the incandescent light bulbs with LEDs, installed cabin insulation, and fixed some mechanical issues in the car.

Video updates are here, for those who like videos:

We're probably working on our precharge relay next. Also need to figure out what we need between the BMS and the wall plug. Would be happy to hear recommendations on these steps!

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mons2b

· #37 · Jan 1, 2022

wjbitner said:
I would say the cheapest would be to use a wreck Nissan Leaf. However, assuming you want to keep the manual transmission, there is a far amount of effort involved in matching a Leaf motor to a different manual transmission, and a learning curve on how to control the Leaf systems. On the other hand, depending on the dimensions, you might be able to make the Acty a front-wheel drive using the Leaf front-end, depending on how much you are willing to cut and weld to the Acty. Looks like a fun project for sure.

I’ve seen tons of people mating leaf motors to manual transmissions. Oddly they seem ideal for it. Not much learning curve if you can afford a resolve ev box. IMO the easiest solution these days unless you go for a simple dc motor system

brian_

· #38 · Jan 1, 2022

mons2b said:
I’ve seen tons of people mating leaf motors to manual transmissions. Oddly they seem ideal for it.

I don't know about "tons", but it is certainly being done. Unlike many EVs, notably all Teslas, the Leaf motor unbolts from the transaxle as a usable motor with a complete housing; that makes mounting it to a different transmission much more practical. Other motors provided for production EVs by suppliers who don't also build the transaxle (perhaps Siemens) are likely to be similar, but the Leaf is far more common than any other EV that might have this feature, so both a supply of salvage motors and aftermarket and hobbyist support is much better than for the alternatives.

Acty DCty

Discussion Starter · #39 · Jan 1, 2022

We've already got a motor, so unless we break it or it doesn't work, we're all set there. Interested in folks' thoughts on how to set up precharge relays, and what parts we need to plug the BMS into the wall.

remy_martian

· #40 · Jan 1, 2022

It's got new paint, so of course the motor will work.

You should have changed the bearings out while you had it apart, though.

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