New BAC-0282P controller has problem

[hardmouse]

I just got BAC-0282P controller and trying to connect to motor, however, as soon as I connect to battery I figured something wrong. The red wire(+) and black wire(-) for battery is actually shorted. Is that normal? or what did I do wrong?

[Bikemad]

Are you sure it is shorted, or could it just be the normal big spark that is very noticeable when you first connect the power?

This alarming spark is caused by the initial current surge as the battery instantly charges the capacitors in the controller up to battery voltage in a split second.

If, after the initial big spark, you can keep the wire connected without any heat building up in the wire, it is probably OK.
However, a direct short across a battery lead connection can instantly melt the copper terminals:






..and I discovered that it doesn't do your fingers any good either:



If you have a 40 Amp fuse fitted to your battery, it should blow instantly if the battery power lead was accidentally short circuited.

Alan
 

[hardmouse]

Yes I tried and tested. 100% sure they are shorted. I connect 6V battery and LED through the + & - pole from controller and I can light up LED.

[Bikemad]

Testing with an LED will not indicate a short circuit, as the controller will allow enough current to pass through to light up a typical LED.

To prove this, I tried your test on one of my controllers using a 6V battery and a very bright 3.6V LED and what I thought was a 150 ohm resistor. I must have put the resistor back into the wrong bag last time I used it, as it was only a 15 ohm resister and the poor little LED was drawing 120mA through the controller instead of ~20mA.

Try using a mains voltage electric kettle or iron (switched on) in series with your bike battery and see if your battery gauge LEDs light up. If your controller is shorted, the LEDS would not light and the kettle element (or iron) should start to warm up.

If you have access to a voltmeter, try measuring the voltage at the battery connections on the controller with the appliance still connected in series. A very low voltage reading could be indicative of a short, a high voltage reading at the controller (and a very small voltage reading across the appliance) is what I would expect if the controller was not shorted.

Alan
 

[hardmouse]

This is what was happening.
I connected 5 wires connector(the biggest white one) and 3 thick wires(Green,Blue,Yellow) to my motor, then I connect black and red wire to my LIPO battery(6Sx2). Last thing I saw is a vary large spark (or fire) coming out from connector and it almost burn my hand.


Can you tell me which part goes wrong? Thanks for help.

[Bikemad]

If the polarity of the battery wiring is definitely not reversed, then the controller must be dead.

Alan
 

[hardmouse]

I use the same battery same wire on other machine it works fine. So, what do you suggest? Return the controller and how?

[Bikemad]

Contact the dealer you purchased it from and explain that the controller is faulty and ask what needs to be done to obtain a working replacement controller, and then fit a suitable fuse into your battery wiring!

Alan
 

[hardmouse]

I bought directly online. Try to connect them by email but never replied. Do you know any proper email I can contact with?

[Bikemad]

Try sending an email to David (wyh@goldenmotor.com) and briefly explain the problem to him.

Alan
 

[hardmouse]

Thank you Alan.

[hardmouse]

Finally, David promise me to send me a new one and he did and he will test it personally before ship to me. Thanks! David!
However, when I got it today I can't wait to go home to try it out. Since the last bad experience it almost burned my battery I decide to try again if the battery connection are shorted. Unfortunately, it did. Yes, the battery wire comes out from controller is shorted. See image below:

I connect 10mm LED with 6V battery through the black- and red+ wire from controller. The LED lights up!!! Does it mean the wires were shorted? Or it's me who stupid enough to test it that way??
Hopefully someone could help me out of this. Thanks a lot!

[Morgen 3Eman]

If the LED requires 10 milliamps to light, I don't think the controller is shorted, it is probably just the 5v system drawing power..... Now if the LED  requires 3  AMPS to light, yeah, you have a short.   

If you were "David", would you say you tested the controller and found it satisfactory if you hadn't actually done so?  I don't have a clue who "David" is,   but most of the folks I know wouldn't put their name to it without actually testing it. 

So what to do?  You surely don't want to damage your battery, and your experience so far has not been exactly wonderful.

First off, make sure you have the correct polarity at the battery.  Is the positive marked terminal really the positive voltage source?   If that is correct, then what?

Maybe follow Alan's suggestion?


So then, do you have a toaster or a waffle iron, or a clothes iron or something with a high power heating element controlled by a bimetallic switch?  And a voltmeter?   If you do, you can jumper wire the heating element in series with the controller, and measure the voltage drop across the heating element when you apply power.  If the controller is shorted, you will see battery voltage across the heating element, and if the controller is ok, the voltage across the element should be very low.  The high power resistor of the heating element will keep the current to a few amps, even if the controller is a dead short. 
 
Please feel free to ignore every thing I have said, my wife does it all the time.  But please pay attention to polarity. 

TTFN,
Dennis

[Bikemad]

Dennis is absolutely correct, that 10mm LED requires less current than the controller draws on standby, therefore the current flowing through the LED will be sufficient to allow it to light up.

Testing with an LED will not indicate a short circuit, as the controller will allow enough current to pass through to light up a typical LED.

Although that LED has a typical current draw of ~20mA (0.02A), a current of just 1mA is sufficient to visibly light up the LED, but if you try the same test using a 5W bulb instead of the LED, then the bulb should not light.

As Dennis also mentioned, make 100% sure the battery polarity is correct, otherwise you would experience a virtual short circuit, as the current will easily flow through the controller's MOSFETs in the reverse direction, giving the impression of a short circuit on the power connections.

As your LiPo pack has no BMS to control the maximum current flow, I strongly recommend that you fit a suitable fuse or circuit breaker into your battery supply circuit, so you won't have to worry about your LiPo pack suddenly turning into an incendiary device should a short circuit or reverse polarity occur!

Alan
 

[Morgen 3Eman]

I  strongly agree with Alan about the fuse.   One thing to consider when selecting a fuse is that the rated current is what it will carry indefinitely, and that a fuse will carry a short term over current far about its rating.  A 30 amp fuse will easily carry 45 amps for a short time, or 35 amps  for a long time, but if you short your battery, the fuse will blow in milliseconds. 

I had a lead-acid battery explode in one of my Mini Coopers, and it sounded like a 40mm cannon going off in the boot.  I do not recommend the experience.

TTFN,
Dennis