1979 XS750 electric conversion

[biothundernxt]

Thanks, I have not posted because I am waiting for parts to arrive. The virus slows everything down I guess.
The factory in China (QS Motor) says it's going to take at least another 10 days before they can ship it out, and I am still waiting on my BMS to arrive.

I will post a lot more pictures once more things arrive.

I have found some interesting information about my motor controller though that is going to require me to re-pin the connectors;
The thermal sensor wire is routed to a different connector than the one that the motor uses.

[Csecrist12]

Really good write up and project overview. Interested to see how the hub motor is going to work in that setup.

I'll be following to see your setup and documentation.

Have you done any wiring diagram research and how you may implement the 12v components that are already on the bike? What charger are you going with and can it be programmed?

I am going to be following suit this winter on my project similar to yours, except using a '98 Kawasaki zx6 frame and some other bits. Looking forward to see where you come to.

[biothundernxt]

Latest update:
My contact with QS Motor says that the motor is completed and will be shipping this week.

My BMS arrived 2 weeks ago, and I finished wiring up the battery.
IMG_20200815_164834.jpg
I will post more photos and details when my motor arrives.

[biothundernxt]

Really good write up and project overview. Interested to see how the hub motor is going to work in that setup.

Thanks! Yeah, I know that using a mid motor is the better option, but a hub motor is simpler, and this is my first build, so I figured that I would start there. Also programming the motor controller for this motor is much simpler.

I'll be following to see your setup and documentation.

Yea, I figure that there will be a lot of scattered information, and I am sure I will have to change a few things. So I plan to re-write this thread after I have everything completed and working like I want it.

Have you done any wiring diagram research and how you may implement the 12v components that are already on the bike?

Not yet. That is going to be one of my next steps though. I want to use as much of the existing parts from the original bike as possible. As for getting the 12v systems to run, I plan to use a DC-DC converter to power accessories such as lighting, and some computer systems. The DC-DC converter takes the 96v power from the battery and steps it down to 12v (or around there). I may also integrate a small 12v battery to help be get the main power contactors online when starting up the bike.

What charger are you going with and can it be programmed?

Good question. I do not believe that it can be programmed, but it is an AC to DC charger specifically for lithium batteries at my desired voltage (96v nominal) and it handles the constant voltage/constant current for charging. The unit is capable of outputting 2.1KW. It handles either 120 or 240v, but puts out considerably less power when running at 120v. I plan to connect this system with a J1772 (standard electric vehicle charging plug) and an IEC C-14 (standard 3 pin power inlet) with some circuitry to ensure that the circuit is never connected to both plugs at once. Charging time with the J1772 should be about 2 hours from empty, while with the IEC C-14 from a standard wall outlet should be closer to 8.
Here are some photos of the unit:
IMG_20200712_155602.jpgIMG_20200712_155609.jpg

I am going to be following suit this winter on my project similar to yours, except using a '98 Kawasaki zx6 frame and some other bits. Looking forward to see where you come to.

Nice! sounds like a fun project. I will look forward to seeing your write-up when you post it.

[biothundernxt]

The text in the second image of the charger is small and unreadable, so I am posting it again here in the hope that it is clarified:
IMG_20200712_155609.jpg

[soyachips]

My BMS arrived 2 weeks ago, and I finished wiring up the battery.

I’m thinking of using the same BMS but was concerned about how much current they can handle. The two blue cables it comes with seem a bit small. Do you know what the continuous current rating is? Also what gauge cables are you using for the HV circuit? Thanks!

[biothundernxt]

I’m thinking of using the same BMS but was concerned about how much current they can handle. The two blue cables it comes with seem a bit small. Do you know what the continuous current rating is? Also what gauge cables are you using for the HV circuit? Thanks!

They claim a continuous rating of 300A. The two blue wires look to be 8AWG each, and the larger wires I have connected to those are 4AWG. The current carrying capacity for wire varies depending on who you ask and what you're doing with it, but a good rule of thumb value would be 73A maximum continuous power for 8AWG, and 135A maximum continuous power for 4AWG. These numbers are assuming no air circulation or cooling is involved.

I don't think I will have any issues with the amount of power my motor controller pulls. It has a max continuous draw rating of 240A, and that is going to be hard to achieve for long periods of time. Cruising at 60 on the freeway I estimate will pull closer to 80A.

In any case, I plan to run some load testing of the whole system before putting it into the motorcycle to see where the system is comfortable.

[biothundernxt]

I ended up getting hit with a 250 dollar customs charge on my motor coming in. (ouch..)
But in good news, the motor should be here by tuesday the 8th.
I am really looking forward to running some tests with the electronics.
More photos to come soon.

[Stevo]

You really only pull max amperage from a dead stop or upon hard accelerations. I don't stress out too much about it. But I dont think the BMS will pass anything even close to 300 amps during cell balancing if I read that correctly... Forgive me if I misunderstood what you were saying.

[biothundernxt]

You really only pull max amperage from a dead stop or upon hard accelerations. I don't stress out too much about it. But I dont think the BMS will pass anything even close to 300 amps during cell balancing if I read that correctly... Forgive me if I misunderstood what you were saying.

The cell balancing current is only like an amp I think.
It does not auto balance unless you have that setting turned on, and then only when you're charging, but you can manually initiate a balance from the app if you want to.

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