Open ReVolt (Cougar) Controller

I recently got an e-mail asking me a few questions about the Open ReVolt controller.

Many of the questions were asking how it compared to other controllers, the features and benefits, and my thoughts in general. So, here goes:

I think the ReVolt Cougar compares favorably to the Curtis 144V 500amp. I don’t have the 500 amp Curtis, but I have used 48 and 72 V Curtis controllers, and a friend of mine has the Curtis 144V 500 amp running in his pickup truck. The advantage of the ReVolt (besides being considerably less expensive) is that it also has some great additional features and programming. Like the Zilla, it will run the main contactor for you. You can really tweak the throttle settings. Having a real-time display out to a small computer is pretty slick as well. Also, you can FIX the controller if you ever have a problem with it! Controllers like Curtis are always embedded in a hunk of plastic, so that you have NO access to any of the parts inside. (That’s great for weatherproofing though!)

Changing settings on the ReVolt Cougar controller is easy with RTD Explorer. Just connect a COM to USB adapter between the controller and a computer. Turn both on, and boot up RTD Explorer. When you go to the HELP menu, it gives you a list of commands. Those are the valid commands you can type into the text box in the lower-right area of RTD Explorer. By typing in the various commands and parameters, you can change almost anything you want about the controller. The guy who designed the software is really nice, and always helpful if you run into a software bug.

The EVAlbum doesn’t have the ReVolt controller listed because it IS NOT a commercially available controller that you can just run out and buy. Instead, it’s a concept, a set of plans, and parts list. I did recently send a message to the operator of the EVAlbum suggesting that we add the Open Revolt or at least a Open Source/Homebuilt/DIY category to the controllers list.

I have never used a Logisystems controller, so I can’t tell you how it compares to that.

You could easily ADD liquid-cooling to the ReVolt controller, but there’s really no need for it. It’s your controller – YOU build it, SO if you want to add an extra fan, liquid-cooling, or other options like that, it’s up to you and easy to do.

Overall, it’s a very good controller. The only drawback that I can think of is that it depends on the skill of the person building it. If you are not at all good at soldering, you may end up with a few problems with it. If you are good at soldering, it will turn out great. You also need a good case for it. Cars are outside, in the rain and snow. The controller needs to be protected from the elements. Please make sure to use a nice solid case that keeps out moisture.

Also, if you want to help support the project, you can get a cool Open ReVolt logo decal for your car or controller case. Or, you can order a t-shirt with the same cool design! Paul Holmes, who was the original designer of this project is still in business, now at P&S Power Electronics.

The original project was posted at with a VERY LONG, but good, project thread.  There was also a project Wiki posted at Ecomodder, but since the files there were collaborative and posted by individuals, many of those links are broken or files are no longer available.

I did contact Paul Holmes, and he sent me some of the original files that he had. I put those into a .ZIP file. Those are now hosted right here on Click HERE for that ZIP.

One of the members of the project has been working on relocating and compiling files related to the project. He has been posting them to GitHub. You can see those HERE.

{ 4 comments… read them below or add one }

1 Nick September 15, 2011 at 5:21 pm

I wonder if the open revolt controller can control a shunt wound dc motor?

2 admin September 15, 2011 at 7:03 pm

I would imagine that it could be modified to.
My experience is only with Permanent Magnet and Series-Wound motor controls. Try looking at the Open ReVolt Wiki on Ecomodder, or go to one of the threads there. Those are the real electronical geniuses! I just test pilot electric cars and try to get more on the road!

3 rico March 27, 2020 at 1:35 am

Thank you for compiling the files.
I will try to build one.

Send my regards and thanks to Paul..

4 Enrique September 28, 2022 at 5:59 pm

Thank you for hosting this files

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