Building an EV motorcycle. Batteries: Need opinions.

[TurnNBurn]

Originally Posted by oil pan 4

Yeah that primary wire is usually rated to 60 degrees C.
I just wanted to know if you speced 90'C cables or not.
But its a elecycle so it should matter too much, I am guessing the main power wires will be some what exposed and able to cool?

Oh yeah! The cables and motor and everything will have adequate airflow. It may be a 1996 CBR, but in the end it want it to look like a cafe racer, somewhat exposed guts and all. Also, I was going to have panels and surfaces directing airflow to parts that need to be cooled.

[TurnNBurn]

I have a question regarding the fuses and this diagram:



You'll notice there's some 20amp fuses from the DC-DC converter on the 12v and 76v side. What's the voltage rating of these fuses? Or I should ask, how do you determine the voltage rating of a fuse like this?

[oil pan 4]

The type of fuse and the amp rating for the fuse determines the voltage.
Glass tube type fuses can be rated from 24 or 36 volts up to 250 volts. The lower 5 and 10 amp fuses are rated up to 250 and the 20 amp ones are rated for 36.
Automotive buss or blade type fuses are usually considered to be good for up to 36 volts. (its usually not an issues since 99% of the time they are used on 12v systems)

For the 400 amp high voltage fuse you are going to have to try and find a high voltage motor controller slow blow fuse. That is the closest thing to your application I can think of.

[TurnNBurn]

Originally Posted by oil pan 4

The type of fuse and the amp rating for the fuse determines the voltage.
Glass tube type fuses can be rated from 24 or 36 volts up to 250 volts. The lower 5 and 10 amp fuses are rated up to 250 and the 20 amp ones are rated for 36.
Automotive buss or blade type fuses are usually considered to be good for up to 36 volts. (its usually not an issues since 99% of the time they are used on 12v systems)

For the 400 amp high voltage fuse you are going to have to try and find a high voltage motor controller slow blow fuse. That is the closest thing to your application I can think of.

I have the 400 amp fuse already. It shipped with the controller.

I'm just concerned with the smaller fuses. I checked out lowes and looked at the fuses. The blade fuses, which I was wanting, were rated at 36 volts. So were most of the glass ones. So they looked to be the same.

I didn't buy anything at lowes because I didn't find anything specific. Will the 36v fuses work for this application? Because my bigger main question is how do I determine the voltage rating needed for the fuse?

[oil pan 4]

You can use fuses with 36 volt rating on a 12 volt system.
The voltage rating on the fuse is the max voltage you can subject the fuse to and have it reliably cause an uneventful open circuit when it blows.
If you put a 36 volt fuse on a 250 volt system, when the fuse blows it could create a sustained arc, which would cause a fire or it could explode injuring people or damaging other near by equipment with hot flying fuse bits.

[TurnNBurn]

Originally Posted by oil pan 4

You can use fuses with 36 volt rating on a 12 volt system.
The voltage rating on the fuse is the max voltage you can subject the fuse to and have it reliably cause an uneventful open circuit when it blows.
If you put a 36 volt fuse on a 250 volt system, when the fuse blows it could create a sustained arc, which would cause a fire or it could explode injuring people or damaging other near by equipment with hot flying fuse bits.

What about a 100 volt fuse? I don't see those even online. not 20 amps/100 volts. Is that a typo in the wiring diagram?

[oil pan 4]

If its only needs a 5 amp fuse for a 72 volt system just use a glass tube type.
I believe at 5 amps the glass tube types are rated for 250 volts.
Then at 10 amps and above they drop to 36 volts.
For the 20 amps requirement, the cheapest easiest solution I can think of with out getting a real expensive fuse and fuse holder is to use the glass tube type fuse holder and get a high voltage ceramic body slow blow fuse. Its the same size as the clear glass tube ones but these white tube fuses are rated to much higher voltage. You should be able to get a 20 amp ceramic tube slow blow fuse rated for 250 volts very easy.
I use fuses like this all the time at work.

[TurnNBurn]

Well, I'm stumped. I can't get the light on the controller to come on. I've got the bike wired slightly different than the diagram above. Everything but the 12v system is in place. I'm thinking the issue is with the contactor. It's not engaging and letting power through. Also, I'm trying to power the contactor with the 72v system. Not anything 12v.

I uploaded some pictures, but I'll color code the wiring and write where everything is going, but I have to head out to work.

-edit-
pictures are too big to upload here. So here's a link to them:

https://copy.com/thumbs_public/cYn0C....JPG?size=1024
https://copy.com/thumbs_public/iYirn....JPG?size=1024
https://copy.com/thumbs_public/iYirn....JPG?size=1024

I'm using the 72v SW200 albright contactor, and if I had to guess I'm guessing I need some external power to it? 12volts?

-edit-
Yeah, I went home for lunch just now and hooked up 12 and 24 volts to the contactor. I got nothing from it. Not even a click. I made sure everything from it was disconnected except the alligator clips.

-edit-

Additional info. I guess the contactor requires at LEAST 36volts, because I added an extra 12v battery to the mix, and sure enough it works now. Now I need to wire everything back up. But first...some pants are required.

Does this mean It'll be safe to wire 72 volts to the contactor to activate it?

-edit-
The answer to my previous question is "yes". I guess I ordered the 72v actuated contactor instead of the 12v. Simple mistake, but it's a learning process for me.