How to wire up a controller for a custom electric wagon

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askeese
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I am in the process of building an electric wagon for my daughter and I am not very knowledgable about electrical. I purchased a CT-660B9 controller from TNC Scooters, a 750W 36V moter, (3) 12V batteries, a brake handle with two wires to connect to controller, a thumb throttle to connect to controller and a charger port. Do I need an ingnition switch for this application, and if so, how many wires (2,3,4)? Is there anything else I should need to get this powered up and any suggestions on wiring it together?
THANKS!

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e-doggies
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Re: How to wire up a controller for a custom electric wagon

I'd suggest you also add an inline fuse between the battery and the main switch. You don't need an "ignition" switch unless you want to lock it. How are you getting power from the motor to the wheels?

askeese
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Re: How to wire up a controller for a custom electric wagon

My controller does include an inline fuse to the batter connection. I did find out some more information regarding the ingnition switch, and you are right, I don't need an "ignition switch" but I do need a switch to turn the power on and off (even a toggle) to keep from draining the batteries. I am getting the power from the motor to the wheels with a #25 chain from the motor sprocket to a sprocket on my wheel hub assembly.

e-doggies
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Re: How to wire up a controller for a custom electric wagon

According to the pic and wiring instructions on TNC, the inline fuse is on the "Lock Connector" and is only 5A. You will still need a 40A(?) fuse between the battery and the main on/off switch. (See the last line of instructions on the wiring page on TNC)

Are you using the brake lever and wires just to control the "brake inhibit" function of the controller? (You did not mention any brake cables or braking mechanisms)

The "Lock Connector" must have continuity from one lead to the other or the controller will not turn on. That's where you could put a key switch, or a simple toggle, or just jumpering from one wire to the other will work too. I did that to my LB-37 controller. I cut off the connector and stripped the ends of both wires and twisted them together with a wire nut.

For a main power switch, there are some rocker types that are used on Schwinn scooters. I've used them at 36V and even in an overvolted (48V) S600. I've never had a problem with any of them. Whatever switch you choose will need to be able to handle the full voltage and current from the battery to the motor, so a little 2A toggle would be too small, for example.

Are you planning on connecting the charger port directly to the batteries? Or through the controller? It's much simpler IMHO to run the positive side of the charger port to the positive terminal on the most positive battery in the 36V pack. Attach the negative side of the charger port to the negative terminal on the most negative battey. Interconnect all three batteries with jumpers from positve on one battery to negative on the other. Your controller would not be involved in the charge cycle at all this way.

Can you post a pic of what you're working on? Sounds like fun.

askeese
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Re: How to wire up a controller for a custom electric wagon

First off, thanks for your response, I was definitely not sure what I needed. I will go ahead and get a fuse for use between the battery and main on/off switch. I was thinking that the Lock Connector served as my on off switch, but it sounds like I need a separate switch to power it on and off?

I am using the brake lever and wires to what I thought is just turning the motors off. I have a brake cable from my brake lever to a band brake on my wheel assembly for the actual braking mechanism.

I do have a key switch that I will use for the "Lock Connector" that should be mailed today. Where should I mount the main power switch? Just inline from the batteries to the controller connection?

I was planning on connecting the charger port through the controller, so I won't have to take off the access panel to batteries everytime to charge. I will take a picture and get it uploaded later today. Thanks again for your insight.

e-doggies
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Re: How to wire up a controller for a custom electric wagon

Yes, you will still need a main on/off switch that is heavy enough to handle the entire power load that it might see. If you don't have a main switch, the "Lock" will disable the controller so no one can jump on and ride away, but you will still have a small and constant drain on the batteries, even when it's locked. Hence the need for a main switch.

You can connect the wires from the brake lever to the controller. When you pull the lever to apply the brakes, it disables the controller (actually completes the brake-inhibit circuit), so the motor can'tbe running while you are braking. (a good thing) Brake-inhibit is "normally open" so the controller will function properly even without a connection to your brake lever. If you do use it, be aware that sometimes the little switch in the brake lever will stick in the closed position and you might wonder why your wagon won't move.

Without seeing what you are building, I'd suggest positioning the main switch where it is very easy to reach while riding. Try to minimize the amount of wire involved. The longer the wire, the more resistance it will create. From the most positive battery, connect a red wire to the positive battery terminal and then to the main fuse (as close to the battery as possible), then from the other side of the fuse, go to the "hot" side of the main switch. From the other side of the switch, run a red wire to the positive connection on the controller. From the most negative battery in the pack, run a black wire directly to the controller. All this wiring should be 12AWG.

I still believe it's better to connect the charger port directly to the pack and bypass the controller for re-charging. Could you mount the port in a location that you could access without removing anything? A through-hole in the battery compartment?

Looking forward to seeing this...

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