My first EV conversion: '69 Honda CA160 "Baby Dream"

[mannydantyla]

Time to wire everything together!!



Here is my final version of the wiring diagram:



This is excluding anything that is not required to get the wheel spinning. So, no headlight, taillight, horn, etc. (I still wired up the headlight, tail light, and brake light, just didn't need to see a diagram for that. No turn signals and horn, yet.)

Then I re-arranged the diagram to organize it into the sections of the bikes where the wires would go, this helped me to visualize it while I was doing the wiring, and this is the diagram I kept open while wiring the bike:



The contactor is located deep into the frame, under the seat. I connected all the wires to it before bolting it into place, and there were many of them because I used one of the  large lugs as a distribution terminal for the 72v circuit.



I didn't want to do this at first, but I finally accepted what had to be done. I had to cut and drill holes in the top of the gas tank for some of the components. But I must say, it does look good! (I ended up not keeping the label bellow the rocker switch and LED).





I had access to the back of the motor controller via the hole in the other side of the frame, that made it easy to access the wire lugs. I then covered the hole with a re-purposed chrome Honda clutch cover that I found in a parts bin.



Almost done now!!

 

[harrisonpatm]

I didn't want to do this at first, but I finally accepted what had to be done. I had to cut and drill holes in the top of the gas tank for some of the components. But I must say, it does look good! (I ended up not keeping the label bellow the rocker switch and LED).

I had to do the same on mine, and cut into the tank when I really didn't want to. But it has to fit somewhere.

Looks so clean!

Do you have a link for that voltmeter? Have you used it before, do you know how accurate it is, and whether it's going to respond to voltage sag during rides?

Also, it looks like your DC/DC converter is always on. Is that correct? Worried about parasitic draw at all?

 

[mannydantyla]

Do you have a link for that voltmeter? Have you used it before, do you know how accurate it is, and whether it's going to respond to voltage sag during rides?

That is a very apt question! It is a "voltage charge meter" from Kelly - https://kellycontroller.com/shop/volt-charge-meter/ - and at the end of this post is a somewhat lengthy discussion about it. It should show the voltage sag but I will have to find out soon enough.

Also, it looks like your DC/DC converter is always on. Is that correct? Worried about parasitic draw at all?

The dc-dc converter is turned on by the double toggle switch, which also turns on the precharge resistor across the contactor, so when that is off there should be no parasitic draw. I think.

-------

After the wiring was finished, there was nothing more I could do with the bike still on the table I built for it.

Down on the ground at last! It sat on the table for nearly two years, and once it was on the ground, holy cow! It was suddenly so low looking.







I charged it for just a few minutes (first time ever, even while the batteries sat for nearly two years, which is not good) and then I went on a quick test ride. Everything seemed to work just fine, only there was a little noise coming from the front wheel because, in my haste, I hadn't attached the front brake linkage and this caused a lot of noise to come from the front hub. I secured the front brake to the fork but that was all I had time for that night.



The test drive was extremely short but very promising. It was completely silent except for a little tire noise, some wind noise, and the clanking coming from the front hub. I only got up to about 30mph, but to my surprise I didn't experience any strange effects from having worn out shocks and an extremely heavy rear wheel that is also badly out of balance.

The next morning I took it to the big car & motorcycle show I was working so hard to get it ready for. Thankfully the show was only three blocks from my house because the bike didn't have any foot pegs yet!



When I was leaving the show, I got on the road and once I was clear of the spectators, I goosed the throttle pretty good. Wow it was fast! Much faster than my 200cc Honda CL200, and I wasn't even all the way on the throttle. But immidiatly after that the power started to cut out and the motor shut off, the analog voltmeter was reading zero, and I coasted to a stop. I had to push the bike the two remaining blocks home.

The next day I plugged in the charger and after a few minutes I turned on the bike and it was acting like everything was normal again. But I couldn't charge it for long as I had meet my folks for lunch, and I don't yet want to charge it unattended.

What I believe happened is that the batteries where too low and when I gave it full throttle, it caused a large voltage sag that was enough to trip the battery management system and it shut down the battery. I could have proven this if I had thought to check the battery pack voltage, and if it was reading zero than this theory should be correct.

I need to charge it for a many hours and then give it another test drive. But I want to get some foot pegs before I do any more testing. Gotta walk before you can run, I guess.

When the bike was at the show, the analog gauge was saying the battery was at 50%. The gauge is not a typical voltmeter, it is volt charge meter and the manufacturer (Kelly) says it "indicates from ~80% peak voltage to peak voltage of the battery, corresponding to 0%-100%." I bought the 72v meter because I believed that was what I needed, but now I think I should have bought the 84v meter because that is the peak voltage of my pack, 72v is only the nominal voltage. 80% of 72 is 57, so when the battery is at 57 volts, it will say it is 0%. And when the pack is at 72v, it will say it's at 100%, but the below chart says it's more like 10% charge. (?!)



If I bought the 84v charge meter, 0% would indicate 67v. A difference of 10 volts.

And 65v would indicate 50% on the 72v charge meter (.9 x 72), and the chart above says that is less than 5%. So the battery pack was nearly dead when I thought it was 50%!

I believe I need to order the 84v meter to replace the 72v meter.

 

[harrisonpatm]

That is a very apt question! It is a "voltage charge meter" from Kelly - https://kellycontroller.com/shop/volt-charge-meter/ - and at the end of this post is a somewhat lengthy discussion about it. It should show the voltage sag but I will have to find out soon enough.

I guess I'm wondering because it would be great if it didn't show sag. I got a cheapo digital battery meter, and it quickly became apparent how inaccurate it is. I still use it, because it shows real-time voltage, and thats helpful to see how much sag is going on when I accelerate. But I'm in the market for an external gauge of battery life, percentage wise, and I'm looking forward to your reviews of this one. I love the analog look.

Looks so good, btw.

 

[harrisonpatm]

The dc-dc converter is turned on by the double toggle switch, which also turns on the precharge resistor across the contactor, so when that is off there should be no parasitic draw. I think.

When I look at the diagram, I see two red lines on the right side of the DC/DC converter. The thin one indeed goes to the DP switch, which also turns on the precharge resistor as you said. However, the thicker red line goes to the right side of the contactor coil. Which also is connected to the main battery positive terminal. Is that correct?

 

[SlowCo]

Great result and looking very good :thumb:

 

[mannydantyla]

The dc-dc converter is turned on by the double toggle switch, which also turns on the precharge resistor across the contactor, so when that is off there should be no parasitic draw. I think.

When I look at the diagram, I see two red lines on the right side of the DC/DC converter. The thin one indeed goes to the DP switch, which also turns on the precharge resistor as you said. However, the thicker red line goes to the right side of the contactor coil. Which also is connected to the main battery positive terminal. Is that correct?

You are correct, there is no switch on the main 72v wire to the dc-dc converter which is connected directly to the battery. Instead, the smaller red wire, which is like a signal wire telling the dc-dc converter to turn on, is switched. The documentation calls it the "key switch" https://amzn.to/3V2e6S3

I need the dc-dc converter on before I can turn on the main contactor, since the contactor's coil is 12v. So to turn on the bike, the DP switch is first turned on, which also connects the precharger circuit needed by the motor controller before the contactor is fully closed. Then the key switch and the kill switch are closed and this closes the contactor, and now the controller has full 72v power.

If there is a mistake somewhere in there then I would not be surprised!

Is there a way for me to measure the any parasitic drain from the battery while the bike is off?

 

[harrisonpatm]

You are correct correct, there is no switch on the main 72v wire to the dc-dc converter which is connected directly to the battery. Instead, the smaller red wire, which is like a signal wire telling the dc-dc converter to turn on, is switched. The documentation calls it the "key switch" https://amzn.to/3V2e6S3

See, that's great, I didn't get at first that it was a model that uses a key switch like that. I guess if I was being really curious, I would check to see if that thin red wire is switching 72v or 12v. If it's 72, just to make sure the switch can handle it.

I need the dc-dc converter on before I can turn on the main contactor, since the contactor's coil is 12v. So to turn on the bike, the DP switch is first turned on, which also connects the precharger circuit needed by the motor controller before the contactor is fully closed.

That's always the issue with having a contactor use at 12v coil, you gotta power it with something other than your battery voltage (I'm using the MZJ contactor that you first got, I found a solution that worked for me, having the coil voltage use battery voltage). I like your solution, I didn't know there were DC/DC's that have a key switch. Again, if it was me, I'd still check to see what voltage is actually being switched, but it's probably no big deal anyway; even if it is 72v, I'm sure it's a few dozen mA of current. Another solution some people use is having a separate 12v battery somewhere in their ignition wiring, just for switching the coil. But then you gotta worry about making sure the battery is always charged enough to activate the coil... so you could wire it to the DC/DC converter to keep it charged at 12v, which is another level of wiring... it's all a matter of what works for you in the end.

Is there a way for me to measure the any parasitic drain from the battery while the bike is off?

Can't remember what bms you said you used, but you could possibly just check it while the bike is off and see if any power is being consumed. It might be such a small amount that it's not showing up. You could use a sensitive DC clamp meter or shunt off the main battery +. Also, you could just determine that if you do have parasitic draw, it might just be a little bit and you're okay with it.

For example, I decided to just leave my precharge resistor across the contactor coils all the time, unswitched. My reasoning being, I don't want to have it on a switch, forget to switch it on, then close the contactor and risk damaging my controller. So, I have 5w being drawn by the battery all the time, 120wh per day. For a small system like an ebike, that's a lot. For my 5.5kwh battery, I'm okay with it. I blow through 120wh during 10 seconds of acceleration. If I was storing the bike, I have a circuit breaker I could open to completely isolate the battery. But I'd rather "waste" that 120wh per day than risk one day of forgetting to close my precharge switch and damaging my controller.

I like your solution though. In order to close the contactor, you need the 12v on, which you've also put onto the same switch as your precharge resistor. So its impossible for you to close the contactor without flipping your precharge switch first. Nice. Have you figured out how long it takes for the controller to slowly get the full battery voltage? Stick your multimeter on the (-) and (+) terminals of your controller, while it reads 0V. Flip your precharge switch. Wait for the multimeter reading to slowly climb up to full battery voltage, or at least like 90% of it. Now you know how long you have to wait before closing the contactor.

If you google parasitic losses on Teslas, some people report 1-5% of their battery capacity draining overnight. On a 60kwh battery, that like 600-3000wh lost per day. Yikes.

 

[mannydantyla]

 

[SlowCo]

Great looking bike. Although the seat could be "fatter/thicker" to match better with the overall look.
In Europe there is a "Puch" moped saddle that would be ideal I think:https://www.jmpbonderdelen.nl/zadel-puch-maxi-als-origineel-zonder-opdruk.html
Honda C100 solo seat:
https://www.ebay.com/itm/150571226350

 

[harrisonpatm]

Even though I might agree on the seat, that has to be one of the cleanest builds I have seen. Amazing.

 

[amberwolf]

For example, I decided to just leave my precharge resistor across the contactor coils all the time, unswitched. My reasoning being, I don't want to have it on a switch, forget to switch it on, then close the contactor and risk damaging my controller.

It's possible to build a relatively simple circuit with a small relay that uses the switch you use for the contactor to instead trigger the circuit. The circuit would first turn on the relay connecting the precharge resistor across the contactor. After the voltage on the controller side rises to whatever point you want, it then uses a second relay to switch on the contactor. When the switch is turned off, it can either just shut it all off at the same time(simplest), or disconnect contactor first and then precharge resistor (potentially requires extra parts to store enough charge to last enough time for both to happen, if controller capacitors dont' hold enough).

Would have to work out the whole circuit, but probably only needs two relays, one for precharge one for contactor coil, a resistor and capacitor for an RC circuit timer to engage the second relay based on calculated time for precharge *or* a transistor circuit with it's base on the controller side via resistor divider to turn on at the actual voltage point of precharge complete. Snubber diodes to go across each relay coil. That might be all of it. Fancier functionality can be done with more transistors, or IC chips for even fancier stuff, but not required.

 

[harrisonpatm]

For example, I decided to just leave my precharge resistor across the contactor coils all the time, unswitched. My reasoning being, I don't want to have it on a switch, forget to switch it on, then close the contactor and risk damaging my controller.

It's possible to build a relatively simple circuit with a small relay that uses the switch you use for the contactor to instead trigger the circuit. The circuit would first turn on the relay connecting the precharge resistor across the contactor. After the voltage on the controller side rises to whatever point you want, it then uses a second relay to switch on the contactor. When the switch is turned off, it can either just shut it all off at the same time(simplest), or disconnect contactor first and then precharge resistor (potentially requires extra parts to store enough charge to last enough time for both to happen, if controller capacitors dont' hold enough).

Would have to work out the whole circuit, but probably only needs two relays, one for precharge one for contactor coil, a resistor and capacitor for an RC circuit timer to engage the second relay based on calculated time for precharge *or* a transistor circuit with it's base on the controller side via resistor divider to turn on at the actual voltage point of precharge complete. Snubber diodes to go across each relay coil. That might be all of it. Fancier functionality can be done with more transistors, or IC chips for even fancier stuff, but not required.

Indeed, but I'm still a newbie at the more complex stuff and I wanted to keep it simple for my first build. I'll get there though. What you described, I get, in theory, and ill do some practice on it, then incorporate it into my next build. "Relatively simple" being the key word; I'm not there yet. Whearas the permanently connected resistor is dead simple. Inefficient, absolutely, but kinda failproof

 

[mannydantyla]

New video is up on youtube!

[youtube]JWA5krgAwQ4[/youtube]

I've been having fun riding it around the neighborhood, each time taking it further away from home and going faster. My speedometer is having some trouble but I think I've gotten up to 40mph. No issues at that speed with suspension or anything.

I've found an electrical gremlin: the plastic connector for the dc-dc converter came loose, causing the contactor to open and the bike lost power. It was because the connector is located between the tank and the headlight bucket, so turning the front fork tugged on the wires and caused it to come loose. I fixed it with a zip tie.

I also killed the battery when it was extremely low on charge, and I gave it max throttle, this caused it to sputter and then shut off, and everything indicated that there was no battery power at all. I believe the voltage sagged so low that the BMS shut everything down until it got charged up.

I've also started thinking about turn signals and where to mount them, and I've decided to replace the oem steel rim on the front wheel with an aluminum one that matches the rear wheel.

Oh and I also have a video showing how I programmed the Kelly controller:

[youtube]lFwknCOwdso[/youtube]

 

[nicobie]

Love your EVgrin!

Well done

 

[mannydantyla]

Thanks nicobie!

Top speed is 55mph, just a bit less than I was hoping for. Range without regen on is 20 miles, again less than I had hoped for but not outside the range of what was predicted for a 20 amp hour battery.

I love riding it! It's so different than my gas powered motorcycle, just completely different experience. It's completely smooth and vibration free, and of course silent and odorless.

 

[mannydantyla]

I'm not sure I ever posted a full parts list and some people are asking about that, so here that:

EV Components:

used LG pouch cells
15ah 3.6v LG Chem pouch cells (when new)
200mm x 260mm x 8mm - or - 8” x 10.5” x 3/8” (with the plastic cases)
need to cut these 4p modules to two 2p packs:
https://batteryhookup.com/products/lg-chem-4p-modules-60ah-stackable
20s2p = 72v 30ah and 90amp continuous discharge rate (3c)
but if 2/3 capacity left, then only ***20ah and 60amp discharge rate***
40 cells total, a four pack is $20, that’s $200
max voltage: 84v
min voltage: 50v
peak discharge current: 150amps ???
6.5kw ~= 72v x 90 amps (continuous discharge rate)
4.32kw = 72v x 60 amps (comtinous discharge rate @ 2/3 capacity)
...
range:
at 30mph, expected consumption will be approx. 50 Wh/mile, or 20 miles per kWh
1800 Wh / 50 Wh/mile = 36 miles
however, others say it is 8-14 miles per kWh
1.8 kWh * 8 miles / kWh = 14.4 miles
1.8 kWh * 14 miles / kWh = 25.2 miles
and yet others say 100Wh/mile or 10 miles per kWh
1800 Wh / 100 Wh/mile = 18 miles
....
motor:
http://www.qs-motor.com/product/4000w-spoke-hub-motor-for-electric-motorcycle/
maximum motor current at 72v: 90 amps (as stated in specs)
continuous motor current at 72v: 55 amps (4kw / 72v) (61a stated in the specs)
...
controller
Kelly KLS7245N
90 amp continuous and 270 amp peak (phase current, which approaches battery current as RPM approaches max speed)
...
DC-DC converter:
20w from amazon
https://amzn.to/3M3UFV5
BMS:
DALY 100amp 20s 72v
Charger: https://amzn.to/3rnosi5
Contactor:
https://www.te.com/usa-en/product-1618387-3.html
Fuse:
Kill switch: https://amzn.to/3NXKkKH
display: 72v charge meter from Kelly
rear brakes
how the rear brake bracket from QS works: https://endless-sphere.com/forums/viewtopic.php?f=10&t=89582&start=25#p1316018
Connectors and misc:
charger port: https://amzn.to/3BXeDfm
battery enclosure connectors: https://amzn.to/3fwSg93
wire connector kit: https://amzn.to/3UZbnc3
terminal covers: https://amzn.to/3ydIU8J

Restoration parts:

tank emblems
tank bushings/cushions
tank side covers
tank knee pads
speedometer cable
handlebars
grips
tires
front brake lever
front brake cable
rear brakes
ignitition key
turn signals
swing arm bushings
speedometer lightbulbs
headlight bulb
horn and button
handlebars
seat
Wheels:
tires that came on the bike:
- front: 3.25 - 16
- rear: 2.75/3.00 - 16
- stock rims are both 1.85” inner, acceptable for up to 3.5” wide tires

Budget:

CA160: $500
Emblems: $30
handlebars, grips, horn: $100
tank side covers: $56
QS 4kw hub motor $335
Kelly motor controller $228
disc brake $30
twist throttle $5
shipping for motor etc $218
cart jig thing $75
antique license plate. $55
primer: $20
tires: $152
speedometer cable: $18
tank rubber cusions: $40
spare key: $14
battery cells: $225
^^ shipping: $55
tubes: $53
headlight: $27
clear paint: $40
wire connectors: $23
horn button: $15
various things: $130
2k urethan paint: $110
wire and tape: $50
sheet metal & tools: $200
dc-dc converter $22
BMS $65
contactor & accessories: $114
^^ shipping: $30
charger: $60
connectors: $20
more connectors: $40
handlebars: $50
seat: $50
handlebars (again): $71
inner tube: $20
hand controls: $40
distribution blocks: $35
crimper tool & connectors: $35
contactor: $70
turn signals: $60

Total: $3,586

 

[mannydantyla]

I always finish my projects like this by going out and taking some glamor shots.

But first lets get to what everyone has been asking for:

• top speed: 55mph (88kph)
• range: 20 miles (32 kilometers)
  • without regen braking activated
  • thats on used, old batteries, new batteries would probably get 30 to 40 miles.

I need to program the motor controller again and activate the regen mode so I can see how many more miles that would add to the range, but my wife is learning how to ride it (the bike is for her) and that would just make it more complicated I think.

Ok now for the photos!

 

[SlowCo]

Wow, what a gorgeous conversion
I hope your wife is happy with the result?

 

[Elektrosherpa]

This is really a stylistically great conversion !

The battery box with its "classic" form is matching the rest of the bike perfectly.

And the hub motor does not disturb either.
Maybe I had removed the black paint from it, so that it looks more like the front hub.
But this is a very very small detail.
Else I dont see anything which could have been made better.

 

[mannydantyla]

I just put this video together, showing the entire build from start to finish, hope you enjoy it!

[youtube]9-WlJsjmed4[/youtube]

https://www.youtube.com/watch?v=9-WlJsjmed4

 

[tomjasz]

That was my dream bike in 1967. What a sweet and wonderful build. Nice work!!! I wish I had local pals that enjoyed this sort of adventure!

 

[MDG]

Not sure if you’re checking messages still. I’m doing a CA160 as well and noticed you still have the side stand. I do plan on using the center stand but curious how you mounted the side stand? I believe the original is part of the foot peg mounts that bolt to the motor. Did you just bolt this assembly to the bottom of your battery box?


EDIT: zoomed in on the pics and see you did some custom brackets off the frame