ESC with highest maximum continuous amp draw rate
 

I'm looking for an ESC with the highest maximum continuous amp draw rate for a special project of mine.

Application: I built an e-puller out of an old nitro E-Revo I had lying around. I've locked the diffs, and added 3lbs lead weight up front (but under the body shell) to be better able to get the traction down. I'm currently running a Mamba Monster on 6S and a 350KV brushless outrunner motor from hobby king. It gets warm but nothing gets hot. Top speed is maybe 6 or 7mph, which is perfect for what I'm doing ... I'm using it to pull the kids around in a wagon. It's great fun, but when going up hills (like the driveway), the ESC shuts down for a couple of seconds (and if you're not ready for it, the wagon will start to roll back down the driveway).

So I've heard the Monster has a maximum continuous amp rating of 120A. I have a 2nd gen RX8 lying around that I could use, and I understand those are rated at 210A, so that should be better. But I've also had one RX8 catch fire on me and another let out the smoke (unrelated applications), so I'm a little gun-shy. Viper has an ESC rated at 220A, which isn't enough more to justify buying it when I already have the RX8 I guess. I think the Castle XL2 is only rated at 200A. Is there anything out there that's significantly higher than 200A?

The only thing I can think of is using a marine esc. The Heifei Swordfish is rated at 300A continuous. It's fully programmable, data logging, and will take up to 15s lipo. So you could wire a pair of 6s lipos in series which should lower the amp draw. Attach a pair of fans to the esc and away you go.

I would be careful comparing ratings between manufacturers, as they may not be rated with the same methods. I really don't know, but I would think the XL2 would have quite a bit more capability, being intended for considerably heavier 1/5 scale. And would still have brakes, something I would suggest would be very important safety consideration for your application, not sure if a marine ESC would have that.

Generally raising the voltage won't lower the amps by itself, it will raise amps. Lower amps require a change to the load, generally a lower kv motor all else being the same. Possibly a gearing reduction with same motor, assuming the motor isn't driven to a range where it is relatively inefficient. Higher voltage can be effective for high power, but takes appropriate adjustments.

Thanks. Good thought on the marine ESC, but yes, I would like brakes.

I don't have a good way of reducing the gearing down any further than I've already done. I did find a 225KV or thereabout motor, which would effectively reduce it by another 1/3, and that is an option, but then I would have to go to an 8S setup and I don't have any 4S packs. Suppose I could go 9S and run 3 3S batteries in series, but most of my 3S packs are matched pairs for use in my E-Maxx and E-Revo. Maybe 3 3S 2100KV packs from my 450 heli?

I was wondering whether there was some obscure company out there making 300A or 400A ESCs that would work for surface vehicles, but sounds like that isn't the case.

So I'm going to try the following 2 approaches using supplies I already have:
1. I have a sneaking suspicion that the old green Mamba Max ESCs have been one of the more underrated ESCs out there, so I'm going to switch out my motor for a 775KV motor and a 4S setup with separate BEC on a Mamba Max and see what happens.
2. if that doesn't work, I'll try the Tekin Rx8 on 6S and the 350KV motor.

Then last resort, if neither of those solutions work, I'll pick up a Castle XL2 and somehow cram it under the shell, still run on 6S, and see if I have any better luck.

Is 450A and 24s enough? :)

Although I must say I have no experience with them, maybe try an Alien Power System ESC.

They are ESCs more or less specially designed for electric vehicle use like e-bikes and scooters and such. They seem to be based on Flier ESCs but with own PCB Design and modified software for electric vehicle usage. Prices are also very reasonable.

MGM has up to a 400 amp, 64 volt version. I'm currently using a MGM controller in my 1/10 TMM-7035-3 (70 amps, 35 volts) in my TLR 22T. I'm happy with it overall. One issue I've had with it is the motor temp went up using the same motor I ran before while in sensored mode. In sensorless, temps went right back down. I think it has to do with the timing, but swapped the motor out for a different option that I was looking for an excuse to try anyway. I've since stuck with the option I tried as it suits my style better. Amazing ESC though.

http://mgm-controllers.com/index.php...llers-x-series

Thanks for the suggestion, but MGM is really expensive and I have a bad history with them. I bought 2 of their HV controllers back when I first did the E-conversion of the Revo (before Traxxas made the E-Revo). Paid a lot of money for them, the programming was incredibly complicated and I never actually got them to work right. Now this was early on and no one else really had anything worthwhile, but it left a bad taste in my mouth.

Alien Power Systems has me very intrigued. If the in-house solutions I've identified don't work, I might just have to give them a try ... or at learn more about them ... see if anyone has had any experience with them. Thank you!

I think with your in-house solutions you are at a high risk of frying your ESC, these things are just too small to constantly put so much wattage through it.

Maybe have a look at endless sphere forums, there are a lot of people there who sit on a pile of burnt-out 'RC grade' gear that they have been trying to use with heavy stuff like e-bikes etc. Some got it to work, some didn't, but I think for those who got it to work, it was too much "on the edge".

You'll also find a very interesting thread about these ESCs there, the owner of the business sent a test-unit to some forum guru guy on the forum, but it never got tested (Or maybe it got tested and the forum guru didn't want to admit that it did last actually, who knows)

Thanks; I just took a quick look at the Endless Sphere forums and someone posted that Alien doesn't ship to the US?

In any case, I should know by the end of the week how my systems work. If I burn up an old Mamba Max, that's fine. Raining today so tomorrow will be the earliest I can do some testing.

I know this sounds crazy, since your not concerned about weight.

Why not build up a simple water cooling system for the ESC, it would help fight the thermaling. All you would need is a small inline water pump, a copper block that fits over the mosfets on the board, and a small radiator with fan. All powered off a BEC. Only reason something like this wouldn't work normally is most people are concerned about weight.

Looking at cooling solutions for PC would be a good starting point. A CPU block adapted to the ESC could be done, the only thing that may be a challenge is finding a radiator. It may be a one off type of thing, but sweating copper pipe is pretty doable at home.

This is just putting ideas out there, I'm not sure on how realistic this is. This idea is just to help with the heat problem you seem to have with your current MM ESC

Now that is some outside of the box thinking ... I love it!

When you say MM, I assume you're referring to the Mamba Monster, not the Mamba Max that I just swapped in. So I don't even think the Mamba Monster is getting hot. There's so much plastic around it that it's hard to be sure, but the fan isn't switching on, and the plastic case feels cool to the touch. It's just shutting down momentarily when under load. So I assume some sort of internal fuse is flipping when the amps get too high, presumably to protect the ESC from flowing too many amps. Strange because I would think that heat would be a biproduct, but I'm not experiencing it. Things should dry up over here by the evening, so when I get home from work will try it today with a Mamba Max on 4S and see how warm it gets.

A peltier cooler with a decent heatsink would work as well, and be pretty compact.

Those things are sweet, but for something like this, that adds way to much complexity I think. They are a good draw on power alone, but with added cooling for the hot side, you would still want water cooling.

I would deff recommend swapping in a Monster for sure, the MMP is a nice controller. However I wouldn't pull any more amps through it then a normal motor. Like 10th scale stuff, I'm currently putting one in a 1/8 buggy and I'm a little afraid this will be asking to much from it.

I had some time to think about this on my way home from work. The best I can suggest is to run a boat ESC, and to hook up a mechanical brake. You really do need a super high amp ESC and you may want to run more volts with such a low kv motor.

Using a mechanical brake will take stress off the motor and ESC, plus it would provide a fail safe if the motor or esc does let go. Just get the strongest servo you can manage, and the largest Disc brake you can make fit. You want maximum clamp and leverage forces, considering you are pulling kids up a hill in a wagon.

Braking power & control needs to be appropriate and in some moderation. The truck won't offer much braking safety after it locks up and jackknifes. Safe trailering is never about how much one can pull, it's always about braking capability.

Agree some type of fail safe would be good.