thin red wire

[jason72]

hello guys.

there is something i dont understand...
today i got lyen's controller.
the battery connector has three wires.
one red, one black and one thin red wire.

how am i supposed to connect the thin red wire?
should i split the battery's red wire into two wires and then connect it to the controller?

i dont understand this.

 

[Philistine]

The thin red wire connects the MCU in the controller, so think of it like an ignition wire. You can put a switch in line with that thin red wire, which then connects up with the thick red wire to your battery red wire. This will allow you to turn your controller on and off with that switch.

If you don't want such a switch, you can just join the thin red wire with the thick red wire, but it is good to have a switch per the above, as it allows you to turn off the controller without having to connect and reconnect the power wires. Just be aware that when that thin red wire switch is off, you are still using a very small amount of power (as the battery is powering the caps), so if you are leaving the bike for weeks on end unused, you should also disconnect the main power wires.

Cheers, Phil.

 

[jason72]

The thin red wire connects the MCU in the controller, so think of it like an ignition wire. You can put a switch in line with that thin red wire, which then connects up with the thick red wire to your battery red wire. This will allow you to turn your controller on and off with that switch.

Cheers, Phil.

Phil can you describe how am i going to do this?

 

[Philistine]

If you want to use a switch (which I would suggest you do), then buy a switch (it can be any switch, doesn't matter if it is low amp rated, as there is very small current going through the thin red wire). Put the switch where you would like it to be - eg handle bars etc..), then get some thin wire and solder or connect it to the thin red wire coming out of the controller, run this wire to the switch, and run another wire from the switch back to the controller and connect it with the thick red wire coming out of the controller, which you then connect to your battery.

If you don't want a switch (ie if you just intend to connect and disconnect your power wires as the way to turn the bike on and off, you can just join the thin red wire with the thick red wire, when connecting up the battery.

The switch option is just a way to allow you to power down the controller without disconnecting the battery.

 

[jason72]

i see.

so the best way to connect the battery and the controller is:
SPLIT the red battery wire into two wires.
then connect the three battery wires to the three controller wires.

am i right?

 

[dogman dan]

Not really. You want all the wire to the battery going to all the wire on the big wire to the controller. Just make a Y connection to the battery wire if you are going to use the switch.

 

[Philistine]

No, what I am saying is, you will have the red and black battery wires connect up to the red and black controller wires. Your thin red wire can just join with your thick red wire, when connecting with the battery red, but your choice is that if you like, you can also put a switch between the the thin red wire, and where it connects with the thick red wire on your controller. That switch is then effectively disconnecting your thin red wire from your thick red wire (on your controller side). Including that switch (that connects and disconnects the connection between the thick and thin red wire on the controller, before they connect to the battery red) is your choice. I suggest doing so, as it allows you to turn off the controller without disconnecting the battery from the controller.

 

[dnmun]

you should ask lyen, the small wire supplies the circuit current for the controller, and the large red wire goes to the mosfets in the output.

 

[jason72]

ok, i am going to buy a Y connection from an electronics shop.

 

[dnmun]

why?

 

[jason72]

to avoid splitting the red [+] wire of the battery.

 

[dnmun]

no, no, the thin red wire is for the controller circuit current, you have to put a switch in that line from the battery so the controller can be turned off. otherwise the controller will drain the battery pack. you can leave the large red wire to the mosfets connected since no current leaks through them until they are turned on. so if the controller circuit current is switched off, then the mosfets are turned off and you can leave the large red wire connected and not have the spark problem eating up the connectors.

 

[jason72]

guys i really dont understand how to connect it...
can u post me a video or an image to show me how to do it please?

 

[mud2005]

well Im no artist, but there ya go. hope that clears it up.

 

[jason72]

so i need an extra small cable connected to the battery red cable right?

 

[d8veh]

I think you've nearly got it, but I'll have a go to try and make it clear. First get a switch that can be mounted on or near the handlebars. Then solder two wires to it long enough to reach the controller and battery. Thin wire is OK and color doesn't matter. If your thin red wire goes into a three-way connector, cut it at the connector. Join one switch wire to the thin red wire. Join the other switch wire to anywhere that has battery +voltage, which can be directly to the battery + terminal or anywhere on the thick red wire where you can solder it on without having to cut the thick red wire. If your thin red wire is already joined directly to the thick red wire, just cut it (the thin one) half-way along it's length and join the two switch wires, one to each side of the cut.

Some throttles come with a switch, which can be used like this, which puts the switch right where you want it, like these two:
http://www.bmsbattery.com/accessory/390-thumb-level-throttle.html
http://www.bmsbattery.com/ebike-parts/54-thumb-level-throttle-with-battery-meter-and-a-switch.html

 

[mud2005]

simply put: cut the thin red wire and solder in a switch.

if you want to see how this works, cut the thin red wire, plug in your batteries and you will see that your controller is not working.

strip a little insulation off the ends where you cut the wire and twist the ends together. now the controller works. simple as that. the thin red wire and the larger red wire both go to + on your battery.