Im guessing, a 2x 32 Sabertooth (40amp system, 20 amps per motor)would work, but concerned that the peak could go over the 64amp peak of the Sabertooth, so wondering if i should go to the 2x60, or is that complete overkill?

Sorry I can't find the post right now. A couple of years ago someone did a oist about sizing controllers. I think they said to go 10% over the motor rating, so 2x32 should do it. Maybe get away with a 2x25.

Alan

Thanks for the response I searched again this morning for any kind of rating for the motors, and nothing. But nearly all applications like this are using the 2x25, and since i'm going to be crawling with it, and no sudden high torque starts, i'm thinking the 25 will be ok. If not Ill order the 32 and keep this one as a spare to play with on another project. If i don't smoke it of course lol :O

@Dana 2 x 25 is the one you want You could probably get away with the 2 x 12 if your bot is light... All sabertooths have a built in over current protection which will shut down the sabertooth if you motors try and pull too much current... Remember max of both motors and possibly the controller is listed at 40amps... My guess that is extreme where both motors are close to maximum output... I doubt with what you want to use it for that each motor would not draw more than 10amps... the 2 x 25 will be more than adequate for your needs...

What are the motor's rated voltage?... If the are 24V, running the motors with 24V instead of 12V will drop the amps needed...

@Richard R Thanks Richard IT's a 24 system, but i it's 12v going to each motor. But ive read that it could be 24 going to each, but 12v for the motor and 12V for the brake, so not completely sure. The postings are so random in opinion its hard to figure it out, and nothing listed in the paperwork or on the chair. I think the base is about 60lbs.

The motors are meant to carry people, right? So if your bot when finished won't be weighing hundreds of pounds and you won't be using it in extreme conditions (like robot fighting LOL) then the 2 x 25 will do you just fine...

Remember 2 x 25 means 25amp rating on each of the 2 channels so each motor has available to it a continuous 25amp draw... You'll lucky (if the above conditions apply) if each motor draws more than 10amps each on average...

A good formula to remember...

Watts/Volts=amps

Using the above formula you can see by increasing the volts means you will use less amps... That's why I asked whether you were using 12V or 24V to drive the motors...

@ Richard R Yes, absolutely right, no people, and only adding about another 20-30 lbs tops, so it wont be working as hard as intended by design, plus when moving it will be at a very slow speed for short distances. Still learning on the electrical side of things, obviously lol. Im used to designing Industrial machines, then pass it along to the Electrical guru's to make it actually move, so this is one heck of a learning curve for me.

@Dana no worries ... Like I said, the sabertooth's have a built in overdraw protection so you worst case scenario you bot shuts down trying to climb a steep hill while overloaded with weight... One thing about the sabertooth I would caution you on... there is no reverse polarity protection, so if you accidently reverse + and - .... you will get to experience the wondrous and mysterious magical blue smoke.... .... Don't ask me how I know....