Thread for budget controllers

harrisonpatm

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@neptronix pointed out that it might be useful to have a discussion thread regarding controllers in the budget category. There's lots of good ones out there, many with their own threads specific to them, but I think that a lot of DIYers may fit into the category of people that don't necessarily need or want all the features, maximum performance, infinite tuning capability...

Feel free to discuss and post links here.
 
I'll go with the first one. When making my small moped conversion, I wanted something less than a motorcycle, more than a bike, and a power range to fit it. But it wasn't ever going to be my main form of transportation, I didn't need maximum performance, and I didn't want to spend any time tuning it. So I ended up spending only about 15 minutes on AliExpress finding something in my power requirements, for the cheapest I could get it.

1721223773945.png

Been using it for 6 months now, at least a couple times a week. Hasn't broken yet! But seriously, regarding this thread's theme of budget controllers, this one has been pretty great.

Pros
-Plug and play. Before fastening it to the moped, I bench tested (no load) it on 2 mid drive motors, one without halls (so it must also be able to run sensorless), as well as 3 different hoverboard motors I had lying around from other projects, which had 3 different windings/power ratings. Everything spun up without issue. The "learning" wire function worked the first time I needed it to, when I finally got around to putting it on the moped.
-Price: currently listed at $27.60, plus $15 shipped to US.
-Actually puts out its rated 3000w. I'm running it on 20s Li-Ion, so max voltage about 82v. Using both my BMS and external clamp ammeter, I can see that I'm drawing 35-50 amps when accelerating to my top speeds, and roughly 25-40 amps when cruising at said top speed. So it actually is pulling 2500-3000w continuous, and perhaps even 4000w peak for a couple seconds.
-Threaded connections for phase and battery, with a decent plastic cover
-Seems to be durable plastic construction. Advertised water resistant, haven't tested it, but I'd be fine splashing through a deep puddle.

Cons
-The throttle response is stepped, or at least not smooth. Perhaps this means it's a square wave controller, rather than a true sine wave controller.
-Bit noisy motor operation. Lends to the theory that it's actually square wave. I have a loud chain drive anyway, so I don't mind.

I could also add that it's not programmable, and that you can't use it with a display or something. But being that the thread is for "budget" controllers, that might be a given for every controller in this category.
 
I bought that very same controller a couple of weeks ago. It's part of the test mule for my supercapacitor experiment.
I bought it hoping it had a brake regen function. As far as I know, it might have regen. Can't tell at the moment. I need to put my $79 DD hubmotor in a wheel first. So, that's my question. Does it have regen?
The controller cost me $49, no shipping charge. It was simple enough to wire up and turn the motor. It came with documentation, which helped, but that documentation was for a different manufacturure's contoller.
 
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Well, I put the controller on a DD hub motor bike in order to see if it does regen;

View attachment 361467

.... and it does regen!
Oh, cool. I never bothered to check whether it does for myself, I didn't want it for my build. What kind of regen is it? Variable, on/off, automatic or user-controlled?
 
ml7280_clone-jpg.296477

These ML7280 clones have been around a while. You can find them on Amazon, eBay, or Aliexpress relabeled under different names. The descriptions state 60V/72V (selected using a jumper), 80A; various phase current limits stated (180A to 240A). It doesn't have the programming port that the Sabvoton has, and a few people have attempted to add one, but I haven't heard of any success.

These can be found for $70-$80 and the design is fairly compact. Available documentation is minimal and conductors were not labeled.

The main issue with this controller is that it comes delivered with varying current limits. Mine came delivered at 60A, so a shunt mod is necessary to output the full rated (80A) current:

APL used one in this build, and implemented a refined version of a shunt mod that precisely dials in the current limit compared to traditional shunt mods.

I used the traditional glob of solder method and overshot to 91A. I the limit current to 70A with my Cycle Analyst.

Per the various descriptions, the controller is supposed to support regen and cruise control, but I haven't been successful at getting the features to work, although I only tinkered with it for a few minutes.
The 3 speed switch works great (I'll never get another controller without one): For example, at 76V and 24" wheel, the low speed is 43mph, normal speed is 58mph, and boosted is 65mph.
I bought the first one for $80, but the bought a second one for backup for $70 (dollar cost averaging lol). Because of the detachable wiring harness, swapping should only take a few minutes.
 
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