Controller

Description

The controller is like an ICE carburetor in that it controls (throttles) the electrical current being used by the motor. It has other uses as well such as overload, fault protection plus many other, more or less useful functions that are accessed via various controller wire connections. Of course, this controller may look different than the one you use and the wire functions vary greatly. This type is described here because it seems to be common in the 24-96V Chinese BLDC motor industry. This controller is a non-programmable type. 

Given the variability even within this type of controller, I refer you to an excellent set of Youtubes that explains each wire function: BLDC Controller Learning Board for Beginners . The rest of the set are listed at the end of this one per Youtube standards.

The sizing/motor-matching rule of thumb I found was: 

"If you buy a non-programmable controller, ensure that the control voltage is the same as the motor voltage and the controller power is the same or slightly more than the motor power."

The controller used had a nameplate rating of 48V, 34A, 2000W:

The rest of this controller section gives an overview of installation results and a few enhancements I made to the usual install.

The controller was connected to the motor, twist throttle, and battery according to the instructions from the manufacturer. Here is the end result with the motor cable and throttle wires passing through the firewall and sealed with a 3/4"thick plug made from the 1.25" diameter hole cutter plug. The black terminal board has been removed for clarity, but will be used when a 12V system is needed later (eg. stop light). :

The following closer image shows the connector strip used to connect the battery to controller and controller to motor. The connector strip is strongly suggested as it keeps connections tidier and you can change a configuration easier than hard-wired connections. You will need some suitable ring connectors like these:

..if your battery, controller, throttle do not come equipped. Make certain they are not too big for the connector strip screw-pair dividers.

This photo shows the additional ignition slide switch I used to:

1. provide another, hidden switch for security beyond the twist grip ignition key

2. To be able to switch off the LED built-in voltmeter in the twist grip throttle, and keep battery plugged into the controller. There were 2 sub-reasons to do this:

   1. 1. This prevented any battery drain when main circuit switched off (without this, LED read-out stayed on).

      2.  Allowed main battery connector to remain plugged in when vehicle not in use which resulted in less sparking, corrosion each time the battery was connected.  The fewer times it is connected/disconnected the better (try to disconnect only when need to connect to charger).

Here is a close-up of slide switch with 0 or 1 position printed on face:

It simply interrupts the ignition wire. I soldered in the red wires to blue wires and used shrink sleeves to insulate. BTW, that black thing is an included 3-speed switch so you can set it on a low speed for kids. Why it would be attached to the handlebars is peculiar. It would not take long for my grandkids to figure out the settings and run it at the max!  So I left this switch here and since the cowl has a lock on it, I can set it at suitable speed range for the driver.