Is this motor controller Adequate?

Other Hardware Motors, Mechanics, Power and CNC
1

Following an issue with my motor controller in my earlier post, i don't know whether i can trust a replacement from the seller.
here is my problematic one (25-30A continuous and has an arduino library)
http://www.ebay.com.au/itm/130717806584?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

If i choose to get a refund i have another option:

im planning on using this 2 channel motor controller to control 2 motors per channel of this spec:

http://www.trossenrobotics.com/store/p/5151-RS-540-Motor-12V.aspx

its going to be for an offroading 4wd robot with 4 motors. Will i need to buy 2 of them to compensate for the current or will 1 be enough? or is getting a replacement be a safer option?

2

That motor isn't very big, and suspiciously it doesn't have a continuous power rating
that I can see... I wouldn't expect it to handle anything like the power the motor
controller can handle.

The peak efficiency point seems to be 12V 6.6A, ie 79.2W in, yet mechanical output
power is 66.3W from the speed and torque data given, which doesn't agree with the
71% efficiency figure very well.

I think it can be assumed the motor will run to 7A or so with good airflow round it,
a 20A motor controller is not even breaking a sweat at that power level.

3

I think it can be assumed the motor will run to 7A or so with good airflow round it,
a 20A motor controller is not even breaking a sweat at that power level.

So do i need 1 motor controllers to control 2 motors per channel or 2 motor controllers, "paralleled? or should i just request a replacement of my 30 amp controller?