Why? Battery connection has an extra green line.

[qtipslea]

http://imgur.com/VrFRg

Motor is MXUS 350W from Cell_man.
Controller is also from the kit.
Battery is also from Cell_man.

Why do my batter have an extra green cable?

 

[OlderThanDirt]

There is a spark-arrest resistor inside the battery/BMS (usually 200-ohm, 2 Watt). What you do is wire a green wire of your own to controller fat red positive lead (if your controller didn't come with one). Put a connector on it to match the one on the battery.

When you connect the battery to the controller, first connect the black negative leads together, then the green ones, wait a few seconds while the controller capacitors charge, then connect the red wires together. After that, you disconnect the green wires. No spark and no wear and tear on your connectors.

 

[qtipslea]

Thanks for the reply.

So do I need to use the green wire every time now that my controller has one?

I wanted to know in order to plan future upgrade to the battery for example.

 

[OlderThanDirt]

You need to use the green wire every time you connect the controller to the battery if you want to avoid a spark. If you change batteries (unless it's from Cellman), it is unlikely that it will have an incorporated spark-suppression resistor and you'll need to install one. It can either be on the battery leads or the controller leads, it doesn't matter. What does matter is that the FIRST connection between the battery and controller is through the resistor, followed by the main power leads.

It's not a good idea to leave the resistor connected because if something untoward happens in the controller or motor or their connections, you could get a large current through the resistor and burn it up. If it's installed inside the battery like the Cellman, you will have to open up the battery to make repairs.

Many riders construct a separate 3-wire cable with the resistor installed: Red = power positive, black = power negative, and green = resistor.